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Chapter 2: Technology and Cost

2.1 Overview of Technologies 

In discussing the potential for CO2 emission and fuel consumption reductions, it can be 

helpful to think of the work flow through the system. The initial work input is fuel. Each gallon 

of fuel has the potential to produce some amount of work and will produce a set amount of CO2

(about 22 pounds (10 kg) of CO2 per gallon of diesel fuel). The engine converts the chemical 

energy in the fuel to useable work to move the truck. Any reductions in work demanded of the 

engine by the vehicle or improvements in engine fuel conversion efficiency will lead directly to 

CO2 emission and fuel consumption reductions.

Current diesel engines are around 40 percent efficient over a range of operating 

conditions depending on engine sizes and applications, while gasoline engine efficiency is much 

lower than that of diesel engines. This means that approximately one-third of the fuel’s chemical 

energy is converted to useful work and roughly two-thirds is lost to friction, gas exchange, and 

waste heat in the coolant and exhaust. In turn, the truck uses this work delivered by the engine to 

overcome overall vehicle-related losses such as aerodynamic drag, tire rolling resistance, friction 

in the vehicle driveline, and to provide auxiliary power for components such as air conditioning 

and lights. Lastly, the vehicle’s operation, such as vehicle speed and idle time, affects the 

amount of total energy required to complete its activity. While it may be intuitive to look first to 

the engine for CO2 emission and fuel consumption reductions given that only about one-third of 

the fuel is converted to useable work, it is important to realize that any improvement in vehicle 

efficiency proportionally reduces both the work demanded and the energy wasted. 

Technology is one pathway to improve heavy-duty truck GHG emissions and fuel 

consumption. Near-term solutions exist, such as those being deployed by SmartWay partners in 

heavy-duty truck long haul applications. Other solutions are currently underway in the light-duty 

vehicle segment, especially in the large pickup sector where some of the technologies can apply 

to the heavy-duty pickup trucks covered under this rulemaking. Long-term solutions are 

currently under development to improve efficiencies and cost-effectiveness. While there is not a 

“silver bullet” that will significantly eliminate GHG emissions from heavy-duty trucks like the 

catalytic converter has for criteria pollutant emissions, significant GHG and fuel consumption 

reductions can be achieved through a combination of engine, vehicle system, and operational 

technologies.

The following sections will discuss technologies in relation to each of the proposed 

regulatory subcategories – Heavy-Duty Pickup Trucks and Vans, Heavy-Duty Engines, Class 7 

and 8 Combination Tractors, Trailers, and Class 2b-8 Vocational Vehicles. In each of these 

sections, information on technological approaches, costs, and percent improvements is provided. 

Depending on the segment, the vehicle-level technologies available for consideration may

include idle reduction, improved tire rolling resistance, improved transmissions, improved axles, 

weight reduction, improved accessories, and aerodynamic technologies. Depending on the 

segment, the engine-level technologies available for consideration may include friction 

reduction, variable valve timing, cylinder deactivation, turbocharging, downsizing, combustion 

optimization, aftertreatment optimization, and waste heat recovery. The agencies are not 
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projecting that all of the technologies discussed in these sections would be used for compliance 

with the engine and vehicle standards, for reasons that are also discussed in each section. 

Nevertheless, the potential for there to be technologies other than those which form the basis for 

the compliance pathway set forth by the agencies, or which can be used in different combinations 

or penetration rates than that projected compliance pathway, is an important consideration in 

assessing the feasibility of the proposed standards. Summaries of all of the technologies, along 

with the corresponding costs, fuel consumption and GHG emissions improvement percentages 

are provided in this chapter. A summary of engine and vehicle technologies, effectiveness, and 

costs for HD pickup trucks and vans is provided in Chapter 2.5. Summaries of engine 

technologies, effectiveness, and costs are provided in Chapters 2.6 and 2.7. A summary of 

technologies, effectiveness, and costs for tractors is provided in Chapter 2.8. A summary of 

technologies, effectiveness, and costs for vocational vehicles is provided in Chapter 2.9. A 

summary of technologies, effectiveness, and costs for trailers is provided in Chapter 2.10. A 

detailed analysis of technology costs is found in Chapters 0 and 2.13.

EPA and NHTSA collected information on the cost and effectiveness of fuel 

consumption and CO2 emission reducing technologies from several sources. The primary 

sources of information were the 2010 National Academy of Sciences report on Technologies and 

Approaches to Reducing the Fuel Consumption of Medium- and Heavy-Duty Vehicles (NAS)1, 

TIAX’s assessment of technologies to support the NAS panel report (TIAX)2, EPA’s HeavyDuty Lumped Parameter Model3

, the analysis conducted by NESCCAF, ICCT, Southwest 

Research Institute and TIAX for reducing fuel consumption of heavy-duty long haul combination 

tractors (NESCCAF/ICCT)4, and the technology cost analysis conducted by ICF for EPA (ICF).5 

In addition, the agencies relied on NHTSA’s technology assessment report under contract with 

SwRI and Tetra Tech.6,7,8 In addition, the agencies used the vehicle simulation model (the 

Greenhouse gas Emissions Model or GEM) to quantify the effectiveness of various technologies 

on CO2 emission and fuel consumption reductions in terms of vehicle performance as they are 

evaluated in determining compliance with the HD program. The simulation tool is described in 

draft RIA Chapter 4 in more detail.

2.2 Technology Principles – SI Engines

The engine technology principles described in this chapter for SI and CI engines are 

typically described as applying for gasoline and diesel-fueled engines, respectively. Even so, 

these technology principles generally also apply for engines powered by other fuels, including 

natural gas. In Section II of the preamble to these rules, the agencies describe regulatory

provisions that differ between SI and CI engines. Technologies related to closed crankcases for 

natural gas engines are described below in Chapter 2.11 and in the Preamble Section II. The 

agencies describe technologies and test procedures related to minimizing evaporative emissions 

from natural gas fuel systems in Chapter 2.11 as well as in Section XI of the preamble to these 

rules. The agencies’ approach in this document is to first describe the principles of how 

technologies can work for an engine, without specifying the type of vehicle into which it will be 

installed, or the test cycle over which it will be certified. Later, in Chapter 2.5, the agencies 

describe a subset of these technologies as they apply specifically to complete HD pickup trucks 

and vans. In Chapter 2.6, the agencies describe a subset of these technologies as they apply to SI

engines intended for vocational vehicles. 
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2.2.1 Engine Friction Reduction

In addition to low friction lubricants, manufacturers can reduce friction and improve fuel 

consumption by improving the design of engine components and subsystems. Examples include 

improvements in low-tension piston rings, piston skirt design, roller cam followers, improved 

crankshaft design and bearings, material coatings, material substitution, more optimal thermal 

management, and piston and cylinder surface treatments. The 2010 NAS Report, NESCCAF9

and EEA10 reports as well as confidential manufacturer data used in the light-duty vehicle 

rulemaking suggested a range of effectiveness for engine friction reduction to be between 1 to 3 

percent. Reduced friction in bearings, valve trains, and the piston-to-liner interface would

improve efficiency. Any friction reduction must be carefully developed to avoid issues with 

durability or performance capability.

2.2.2 Variable Valve Timing

Variable valve timing (VVT) classifies a family of valve-train designs that alter the 

timing of the intake valve, exhaust valve, or both, primarily to reduce pumping losses, increase 

specific power, and control the level of residual gases in the cylinder. VVT reduces pumping 

losses when the engine is lightly loaded by controlling valve timing closer to the optimum 

needed to sustain horsepower and torque. VVT can also improve volumetric efficiency at higher 

engine speeds and loads. Additionally, VVT can be used to alter (and optimize) the effective 

compression ratio where it is advantageous for certain engine operating modes (e.g., in the 

Atkinson Cycle).

VVT has now become a widely adopted technology in the light duty fleet: in MY 2014, 

most of all new cars and light trucks had engines with some method of variable valve timing.11

Manufacturers are currently using many different types of variable valve timing, which have a 

variety of different names and methods. Therefore, the degree of further improvement across the 

fleet is limited by the level of valvetrain technology already implemented on the vehicles. The 

three major types of VVT are listed below.

Each implementation of VVT uses a cam phaser to adjust the camshaft angular position 

relative to the crankshaft position, referred to as “camshaft phasing.” This phase adjustment 

results in changes to the pumping work required by the engine to accomplish the gas exchange 

process. The majority of current cam phaser applications use hydraulically-actuated units, 

powered by engine oil pressure and managed by a solenoid that controls the oil pressure supplied 

to the phaser.

2.2.2.1 Coupled Cam Phasing for Overhead Valve (OHV) and Single Overhead 

Camshaft (SOHC) Engines

Valvetrains with coupled (or coordinated) cam phasing (CCP) can modify the timing of 

both the inlet valves and the exhaust valves an equal amount by varying the phasing of the 

camshaft across an engine’s range of operating speeds; also known as VVT. For engines 

configured as an overhead valve (OHV) or as a single overhead camshaft (SOHC) only one cam 

phaser is required per camshaft to achieve CCP. 
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Based on the heavy-duty Phase 1 vehicle rulemaking, 2015 NHTSA Technology Study, 

and previously-received confidential manufacturer data, the agencies estimate the fuel 

consumption reduction effectiveness of this technology to be between 1 and 3 percent over 

average driving patterns.

2.2.2.2 Intake Cam Phasing (ICP) for Dual Overhead Camshaft Engines (DOHC)

Valvetrains with ICP, which is the simplest of the cam phasing technologies, can modify

the timing of the inlet valves by phasing the intake camshaft while the exhaust valve timing 

remains fixed. This requires the addition of a cam phaser on each bank of intake valves on the 

engine. An in-line 4-cylinder engine has one bank of intake valves, while V-configured engines 

have two banks of intake valves.

Some newer Class 2b and 3 market entries are offering dual overhead camshaft (DOHC) 

engine designs where two camshafts are used to operate the intake and exhaust valves 

independently. Consistent with the heavy-duty 2014-2018 MY vehicle rulemaking and the SwRI 

report, the agencies agree with the effectiveness values of 1 to 2 percent reduction in fuel 

consumption over average driving patterns, for this technology.

2.2.2.3 Dual Cam Phasing (DCP) for Dual Overhead Camshaft Engines (DOHC)

The most flexible VVT design is dual (independent) cam phasing, where the intake and 

exhaust valve opening and closing events are controlled independently. This option allows the 

option of controlling valve overlap, which can be used as an internal EGR strategy. At low 

engine loads, DCP creates a reduction in pumping losses, resulting in improved fuel 

consumption. Increased internal EGR also results in lower engine-out NOX emissions. The 

amount by which fuel consumption is improved depends on the residual tolerance of the 

combustion system. Additional improvements are observed at idle, where low valve overlap 

may result in improved combustion stability, potentially reducing idle fuel consumption. DCP 

requires two cam phasers on each bank of the engine. 

Some newer Class 2b and 3 market entries are offering dual overhead camshaft (DOHC) 

engine designs where two camshafts are used to operate the intake and exhaust valves 

independently. Consistent with the light-duty 2012-2016 MY vehicle rulemaking and the SwRI

report, the agencies agree with the effectiveness values of 1 to 3 percent reduction in fuel 

consumption over average driving patterns, for this technology.

2.2.2.4 Variable Valve Lift (VVL)

Controlling the lift of the valves provides a potential for further efficiency improvements. 

By optimizing the valve-lift profile for specific engine operating regions, the pumping losses can 

be reduced by reducing the amount of throttling required to produce the desired engine power 

output. By moving the throttling losses further downstream of the throttle valve, the heat 

transfer losses that occur from the throttling process are directed into the fresh charge-air mixture 

just prior to compression, delaying the onset of knock-limited combustion processes. Variable 

valve lift control can also be used to induce in-cylinder mixture motion, which improves fuel-air 

mixing and can result in improved thermodynamic efficiency. Variable valve lift control can 
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also potentially reduce overall valvetrain friction. At the same time, such systems may also incur 

increased parasitic losses associated with their actuation mechanisms. A number of 

manufacturers have already implemented VVL into their fleets (Toyota, Honda, and BMW), but 

overall this technology is still available for most of the fleet. There are two major classifications 

of variable valve lift, described below:

2.2.2.5 Discrete Variable Valve Lift (DVVL)

Discrete variable valve lift (DVVL) systems allow the selection between two or three 

discrete cam profiles by means of a hydraulically-actuated mechanical system. By optimizing 

the cam profile for specific engine operating regions, the pumping losses can be reduced by 

reducing the amount of throttling required to produce the desired engine power output. This 

increases the efficiency of the engine. These cam profiles consist of a low and a high-lift lobe, 

and may include an inert or blank lobe to incorporate cylinder deactivation (in the case of a 3-

step DVVL system). DVVL is normally applied together with VVT control. DVVL is also 

known as Cam Profile Switching (CPS). DVVL is a mature technology in LD applications with 

low technical risk. 

Based on the light-duty MY 2017-2025 final rule, previously-received confidential 

manufacturer data, 2015 NHTSA Technology Study, and report from the Northeast States Center 

for a Clean Air Future (NESCCAF), the agencies estimate the fuel consumption reduction 

effectiveness of this technology to be between 1 and 3 percent over average driving patterns.

2.2.3 Cylinder Deactivation

In conventional spark-ignited engines throttling the airflow controls engine torque output. 

At partial loads, efficiency can be improved by using cylinder deactivation instead of throttling. 

Cylinder deactivation can improve engine efficiency by disabling or deactivating (usually) half 

of the cylinders when the load is less than half of the engine’s total torque capability – the valves 

are kept closed, and no fuel is injected – as a result, the trapped air within the deactivated 

cylinders is simply compressed and expanded as an air spring, with reduced friction and heat 

losses. The active cylinders combust at almost double the load required if all of the cylinders 

were operating. Pumping losses are significantly reduced as long as the engine is operated in this 

“part cylinder” mode. Effectiveness improvements scale roughly with engine displacement-tovehicle weight ratio: the higher displacement-to-weight vehicles, operating at lower relative 

loads for normal driving, have the potential to operate in part-cylinder mode more frequently. 

Cylinder deactivation is less effective on heavily-loaded vehicles because they require more 

power and spend less time in areas of operation where only partial power is required. The 

technology also requires proper integration into the vehicles which is difficult in the vocational 

vehicle segment where often the engine is sold to a chassis manufacturer or body builder without 

knowing the type of transmission or axle used in the vehicle or the precise duty cycle of the 

vehicle. The cylinder deactivation requires fine tuning of the calibration as the engine moves 

into and out of deactivation mode to achieve acceptable NVH. Additionally, cylinder 

deactivation would be difficult to apply to vehicles with a manual transmission because it 

requires careful gear change control. NHTSA and EPA adjusted the 2017-2025 MY light-duty 

rule estimates using updated power to weight ratings of heavy-duty trucks and confidential 

business information and downwardly adjusted the effectiveness to 0 to 3 percent over average 
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driving patterns for these vehicles to reflect the differences in drive cycle and operational 

opportunities compared to light-duty vehicles. 

2.2.4 Stoichiometric Gasoline Direct Injection (SGDI)

Stoichiometric gasoline direct injection (SGDI) engines inject fuel at high pressure 

directly into the combustion chamber (rather than into the intake port in port fuel injection). 

SGDI requires changes to the injector design, an additional high pressure fuel pump, new fuel 

rails to handle the higher fuel pressures, and changes to the cylinder head and piston crown 

design. Direct injection of the fuel into the cylinder improves cooling of the air/fuel charge 

within the cylinder, which allows for higher compression ratios and increased thermodynamic 

efficiency without the onset of combustion knock. Recent injector design advances, improved 

electronic engine management systems and the introduction of multiple injection events per 

cylinder firing cycle promote better mixing of the air and fuel, enhance combustion rates, 

increase residual exhaust gas tolerance, and improve cold start emissions. SGDI engines achieve 

higher power density and match well with other technologies, such as boosting and variable 

valvetrain designs.

Several manufacturers have recently introduced vehicles with SGDI engines, including 

GM and Ford, who have announced their plans to increase dramatically the number of SGDI 

engines in their vehicle portfolios.

Based on the heavy-duty 2014-2018 MY vehicle rulemaking, 2015 NHTSA Technology

Study, and previously-received confidential manufacturer data, the agencies estimate the fuel 

consumption reduction effectiveness of SGDI to be between 1 and 2 percent over average 

driving patterns.

2.2.5 Turbocharging and Downsizing (TRBDS) 

The specific power of a naturally aspirated engine is primarily limited by the rate at 

which the engine is able to draw air into the combustion chambers. Turbocharging and 

supercharging (grouped together here as boosting) are two methods to increase the intake 

manifold pressure and cylinder charge-air mass above naturally aspirated levels. Boosting 

increases the airflow into the engine, thus increasing the specific power level, and with it the 

ability to reduce engine displacement while maintaining performance. This effectively reduces 

the pumping losses at lighter loads in comparison to a larger, naturally aspirated engine.

Almost every major manufacturer currently markets a vehicle with some form of 

boosting. While boosting has been a common practice for increasing performance for several 

decades, turbocharging has considerable potential to improve fuel economy and reduce CO2

emissions when the engine displacement is also reduced. Specific power levels for a boosted 

engine often exceed 100 hp/L, compared to average naturally aspirated engine power densities of 

roughly 70 hp/L. As a result, engines can be downsized roughly 30 percent or higher while 

maintaining similar peak output levels. In the last decade, improvements to turbocharger turbine 

and compressor design have improved their reliability and performance across the entire engine 

operating range. New variable geometry turbines and ball-bearing center cartridges allow faster 

turbocharger spool-up (virtually eliminating the once-common “turbo lag”) while maintaining 
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high flow rates for increased boost at high engine speeds. Low speed torque output has been 

dramatically improved for modern turbocharged engines. However, even with turbocharger 

improvements, maximum engine torque at very low engine speed conditions, for example launch 

from standstill, is increased less than at mid and high engine speed conditions. The potential to 

downsize engines may be less on vehicles with low displacement to vehicle mass ratios for 

example a very small displacement engine in a vehicle with significant curb weight, in order to 

provide adequate acceleration from standstill, particularly up grades or at high altitudes. 

Use of gasoline direct injection (GDI) systems with turbocharged engines and charge air 

cooling also reduces the fuel octane requirements for knock limited combustion and allows the 

use of higher compression ratios. Ford’s “EcoBoost” downsized, turbocharged GDI engines 

introduced on MY 2010 vehicles allow the replacement of V8 engines with V6 engines with 

improved in 0-60 mph acceleration and with fuel economy improvements of up to 12 percent as 

documented in their technical paper.

12

Recently published data with advanced spray-guided injection systems and more 

aggressive engine downsizing targeted towards reduced fuel consumption and CO2 emissions 

reductions indicate that the potential for reducing CO2 emissions for turbocharged, downsized 

GDI engines may be as much as 15 to 30 percent relative to port-fuel-injected engines. 

Confidential manufacturer data suggest an incremental range of fuel consumption and CO2

emission reduction of 4.8 to 7.5 percent for turbocharging and downsizing. Other publiclyavailable sources suggest a fuel consumption and CO2 emission reduction of 8 to 13 percent 

compared to current-production naturally-aspirated engines without friction reduction or other 

fuel economy technologies: a joint technical paper by Bosch and Ricardo suggesting fuel 

economy gain of 8 to 10 percent for downsizing from a 5.7 liter port injection V8 to a 3.6 liter 

V6 with direct injection using a wall-guided direct injection system;13 a Renault report 

suggesting a 11.9 percent NEDC fuel consumption gain for downsizing from a 1.4 liter port 

injection in-line 4-cylinder engine to a 1.0 liter in-line 4-cylinder engine, also with wall-guided 

direct injection;14 and a Robert Bosch paper suggesting a 13 percent NEDC gain for downsizing 

to a turbocharged DI engine, again with wall-guided injection.15 These reported fuel economy 

benefits show a wide range depending on the SGDI technology employed. 

The agencies reviewed estimates from the 2017-2025 final light-duty rule, the TSD, and 

existing public literature. The previous estimate from the MYs 2017-2025 suggested a 12 to 14 

percent effectiveness improvement, which included low friction lubricant (level one), engine 

friction reduction (level one), DCP, DVVL and SGDI, over baseline fixed-valve engines, similar 

to the estimate for Ford’s EcoBoost engine, which is already in LD production. Additionally, the 

agencies analyzed Ricardo vehicle simulation data and the 2015 NHTSA Technology Study for 

various turbocharged engine packages.

2.3 Technology Principles – CI Engines

2.3.1 Low Temperature Exhaust Gas Recirculation

Most LHDD, MHDD, and HHDD engines sold in the U.S. market today use cooled EGR, 

in which part of the exhaust gas is routed through a cooler (rejecting energy to the engine 

coolant) before being returned to the engine intake manifold. EGR is a technology employed to 
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reduce peak combustion temperatures and thus NOX. Low-temperature EGR uses a larger or 

secondary EGR cooler to achieve lower intake charge temperatures, which tend to further reduce 

NOX formation. For a given NOX requirement, low-temperature EGR can allow changes such as 

more advanced injection timing that would increase engine efficiency slightly more than one 

percent. Because low-temperature EGR reduces the engine’s exhaust temperature, it has not 

been considered as part of a technology package that also includes exhaust energy recovery

systems such as turbocompounding or a bottoming cycle.

2.3.2 Combustion System Optimization

Improvements on the fuel injection system that allow more flexible fuel injection 

capability with higher injection pressure can improve engine fuel efficiency, while maintaining 

the same emission level. Combustion system optimization, featuring piston bowl, injector tip 

and the number of holes, in conjunction with the advanced fuel injection system, is able to 

further improve engine performance and fuel efficiency. Manufacturers have been working to 

improve engines these areas for some time. At this point, all engine manufacturers have 

substantial development efforts underway that we project would be translated into production in 

the near future. Some examples include the combustion development programs conducted by 

Cummins16, Detroit Diesel17, and Navistar

18 funded by Department of Energy as part of 

Supertruck program. These manufacturers found the improvement due to combustion alone 

during this program was 1 to 2 percent. While their findings are still more towards research 

environment, specifically targeting one optimal operating point, the results of these research 

programs do support the possibility that some of technologies they are developing could be 

applied to production in the time frame of 2027. The agencies have determined that it is feasible 

that fuel consumption and CO2 emissions could be reduced by as much as 1.0 percent in the 

agencies’ certification cycles in the 2027 time frame through the use of these technologies.

Some technologies were evaluated but not included in the agencies’ technical feasibility

analysis for the Phase 2 regulation since the agencies do not anticipate these technologies will be 

commercially available by 2027. For example, alternative combustion processes such as 

homogeneous charge compression ignition (HCCI), premixed charge compression ignition 

(PCCI), low-temperature combustion (LTI), and reactivity controlled compression ignition 

(RCCI) technologies were not included in the feasibility analysis for Phase 2. While these 

technologies show good indicated thermal efficiency, fuel savings over the entire range of engine 

operation is still a major challenge. At the current level of development it is not clear that the 

technologies will be in commercial production by 2027. This, however, does not preclude the 

use of these technologies for compliance should manufacturers develop and commercialize these 

alternative combustion or other approaches.

2.3.3 Model Based Control

Another important area of potential improvement is advanced engine control 

incorporating model based calibration to reduce losses of control during transient operation. 

Improvements in computing power and speed would make it possible to use much more 

sophisticated algorithms that are more predictive than today’s controls. Because such controls 

are only beneficial during transient operation, they would reduce emissions over the Federal Test 

Procedure (FTP) cycle, but not over the Supplemental Emission Test (SET) cycle. Detroit Diesel 
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introduced the next generation model based control concept, achieving 4 percent thermal 

efficiency improvement while simultaneously reducing emissions in transient operations in their 

earlier report.19 More recently, this model based control technology was put into their one of 

vehicles for final demonstration under DOE’s Supertruck program.20 Their model based concept 

features a series of real time optimizers with multiple inputs and multiple outputs. This 

controller contains many physical based models for engine and aftertreatment. It produces fully 

transient engine performance and emissions predictions in a real-time manner. Although we do 

not project that this control concept would be in 2017 production, it would be a realistic estimate 

that this type of real time model control could be in production during the Phase 2 time frame, 

thus significantly improving engine fuel economy. 

2.3.4 Turbocharging System

Many advanced turbocharger technologies can be potentially added into production in the 

time frame between 2021 and 2027 and some of them are already in production, such as 

mechanical or electric turbocompound, more efficiency variable geometry turbine, and Detroit 

Diesel patented asymmetric turbocharger. A turbocompound system extracts energy from the 

exhaust to provide additional power. Mechanical turbocompounding includes a power turbine 

located downstream of the turbine which in turn is connected to the crankshaft to supply

additional power. On-highway demonstrations of this technology began in the early 1980s. It 

has been first used in heavy duty production by Detroit Diesel for their DD15 and DD16 engines 

and they claim a 3 to 5 percent fuel consumption reduction due to the system.21 Results are duty

cycle dependent, and require significant time at high load to see a fuel efficiency improvement. 

Light load factor vehicles can expect little or no benefit. Volvo reports two to four percent fuel 

consumption improvement in line haul applications, which would be likely in production even 

before 2020.22

Electric turbo-compound is another potential area that can improve engine brake 

efficiency. These are attained through better vehicle integration and lower backpressure impacts. 

Since the electric power turbine speed is no longer linked to crankshaft speed, this allows more 

efficient operation of the turbine. Navistar reports on the order of a 1 to 1.5 percent efficiency

improvement over mechanical turbocompound systems at 0.5 to 0.7 gm/hp-hr engine-out NOX

levels, but dropping at lower engine-out NOX.

23

 However, this concept may not work well with 

lower engine out NOX as indicated in this report, showing zero benefit is reported at 0.3 to 0.4 

gm/hp-hr engine-out NOX, due to lower available temperature. Navistar reports a 1.6 percent 

fuel efficiency improvement, again as compared to a mechanical turbocompound system.

24

Two-stage turbocharger technology has been used in production by Navistar and other 

manufacturers. Ford’s new developed 6.7L diesel engine features a twin-compressor 

turbocharger. Higher boost with wider range of operations and higher efficiency can further 

enhance engine performance, thus fuel economy. It is expected that this type of technology will 

continue to be improved by better matching with system and developing higher compressor and 

turbine efficiency.

Furthermore, improved turbocharger efficiency when combined with turbocompounding 

was shown in the SwRI study to reduce fuel consumption while maintaining criteria emissions 

limits. Findings show that there is limited scope for improved turbocharger efficiency on 
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engines which do not use turbocompound, because an increase in turbocharger efficiency would 

result in reduced or eliminated EGR flow which in turn would cause the engine to exceed NOx 

emissions requirements.

2.3.5 Engine Breathing System

Various high efficiency air handling (air and exhaust transport) processes could be 

produced in the 2020 and 2024 time frame. To maximize the efficiency of such processes, 

induction systems may be improved by manufacturing more efficiently designed flow paths 

(including those associated with air cleaners, chambers, conduit, mass air flow sensors and intake 

manifolds) and by designing such systems for improved thermal control. Improved 

turbocharging and air handling systems must include higher efficiency EGR systems and 

intercoolers that reduce frictional pressure loss while maximizing the ability to thermally control 

induction air and EGR. EGR systems that often rely upon an adverse pressure gradient (exhaust 

manifold pressures greater than intake manifold pressures) must be reconsidered and their 

adverse pressure gradients minimized. “Hybrid” EGR strategies which rely upon pressure 

gradients and EGR pumps may provide pathways for improvement. Other components that offer 

opportunities for improved flow efficiency include cylinder heads, ports and exhaust manifolds 

to further reduce pumping losses. Cummins reports 1.4 percent through optimization.25 Detroit 

Diesel projects a two percent fuel efficiency improvement through air handling system 

development.

26

 Navistar predicts almost four percent through a combination of variable intake 

valve closing timing (IVC), turbocharger efficiency and match improvements.

24

 A few plots in 

this reference show another four percent, but these are not explained.

Variable air breathing systems such as variable valve actuation may provide additional 

gains at different loads and speeds. The primary gain in diesel engines is achieved by varying 

the EVO event versus engine speed and load, in conjunction with turbocharger optimization to 

minimize blowdown losses. Navistar reports a 1.25 percent fuel consumption improvement.

23

 

Again, all these reference points are referred to a single optimal point conducted at DOE 

Supertruck program.

2.3.6 Engine Parasitic and Friction Reduction

Engine parasitic and friction reduction is another key technical area that can be further 

improved in production moving to the 2020 and 2027 time frame. Reduced friction in bearings, 

valve trains, and the piston-to-liner interface can improve efficiency. Friction reduction 

opportunities in the engine valve train and at its roller/tappet interfaces exist for several 

production engines. The piston at its skirt/cylinder wall interface, wrist pin and oil ring/cylinder 

wall interface offers opportunities for friction reduction. Use of more advanced oil lubricant that 

could be available for production in the future can also play a key role in reducing friction. Any

friction reduction must be carefully developed to avoid issues with durability or performance 

capability. Lube pump as well water pump are another areas that improve efficiency. Navistar

identifies a combined improvement of up to two percent through reduced bearing friction, 

reduced piston and ring friction, and unspecified lube pump improvements.27 In his 2012 paper 

he reports 5.5 percent through a combination of friction reduction and both lube and cooling 

system improvements.23 Later in the same presentation he specifies 0.45 percent demonstrated 

through water pump improvements and 0.3 percent through lube pump improvements. The total 
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number of 5.5 percent seems optimistic, even for a single optimal point. Cummins reports a 

combined number of 3 percent.

25

. Detroit Diesel reports a combined number of two percent, 

with 0.5 percent coming from improved water pump efficiency.

26

 Navistar shows a 0.9 percent

benefit for a variable speed water pump and variable displacement oil pump; piston/ring/liner 

friction reduction as 0.5 percent; bearing friction reduction as 0.6 percent.24 In addition, FederalMogul recently announced new piston ring coatings that can lead to a 20 percent reduction in 

engine friction and looking to the future sees an opportunity to reduce friction by an additional 

30 percent, equivalent to 1.2 percent reduction in brake specific fuel consumption at road load 

conditions.28 It should be noted that water pump improvements include both pump efficiency

improvement and variable speed or on/off controls. Lube pump improvements are primarily 

achieved using variable displacement pumps and may also include efficiency improvement. All 

of these results shown in this paragraph are demonstrated through DOE Supertruck program 

under single optimal point.

2.3.7 Integrated Aftertreatment System

All manufacturers now use diesel particulate filter (DPF) to reduce particulate matter 

(PM) and use SCR to reduce NOX emissions, and these types of technologies are likely to be 

deployed for many years to come. Three areas are considered to improve integrated 

aftertreament systems. The first is to have better combustion system optimization through 

increased aftertreatment efficiency. The second is to reduce backpressure through further 

development of the devices themselves. The third is to reduce ammonia slip out of SCR during 

transient operation, thus reducing the urea consumption. This is in turn translated into reduced 

fuel consumption. Navistar reports a seven to eight percent improvement projected through a 

combination of higher cylinder pressure, injection optimization, and engine/aftertreatment 

optimization.23 Cummins reports a 0.5 percent improvement through improved aftertreatment 

flow (catalyst size optimization and improved NOX surface utilization).

25

 Detroit Diesel projects 

a two percent fuel efficiency improvement through reduced EGR (thinner wall DPF, improved 

SCR cell density, and catalyst material optimization).

26

2.3.8 Engine Downsizing 

Engine downsizing can be more effective if it is combined with the down speeding. This 

is due to increased vehicle efficiency resulting in lower power demand. This lower power 

demand shifts the vehicle operating points to lower load zones, which moves the engine away

from some of the optimum operation points. In order to compensate for this loss, down speeding 

allows the engine to move back into the optimum operating points resulting in reduced fuel 

consumption. Increasing power density by reducing the engine size allow the vehicle operating 

points move back to the optimum operating points, thus further improving fuel economy. Both 

Detroit Diesel and Volvo show the same methodology of how downsizing should be properly 

used.

29,30

 Detroit Diesel also shows that engine downsizing can reduce the friction due to smaller 

surface area as opposed to bigger bore engine.26 

2.3.9 Waste Heat Recovery

Organic Rankine Cycle waste heat recovery (WHR) systems have been studied for many

years. The agencies’ overall assessment of WHR as a fuel saving technology is that it offers 
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great promise in the long term. However, it would take several years to develop, and initially, it 

would be viable primarily in line-haul applications. The agencies recognize the many challenges 

that would need to be overcome, but believe with enough time and development effort, this can

be done. The discussion below highlights these challenges to show why the agencies currently

believe WHR would not achieve a substantial market penetration until 2027.

The basic approach of these systems is to use engine exhaust waste heat from multiple 

sources to evaporate a working fluid through a heat exchanger, which is then passed through a 

turbine or equivalent expander to create mechanical or electrical power. The working fluid is 

then condensed back to the fluid tank, and pulled back to the flow circuit through a pump to 

continue the cycle. With support of the Department of Energy, three major engine and vehicle 

manufacturers have developed the WHR technology under the Supertruck program. Cummins’ 

WHR system is based on an organic Rankine cycle using refrigerant as the working fluid.31,32

The system recovers heat from the EGR cooler, as well as from the exhaust gas downstream of 

the aftertreatment system. It converts that heat to power through a mechanical gear train coupled 

to the engine output shaft. Some iterations of the system also sought gains from low-temperature 

coolant and lubricant heat rejection via a parallel loop. The system includes a recuperator that 

transfers post-turbine energy back into the working fluid loop prior to the condenser. This 

recuperator reduces condenser heat rejection requirements and improves overall system 

efficiency. Volvo has developed a similar system to Cummins’ with variations in terms of 

hardware components, but uses ethanol as the working fluid instead of a refrigerant.33 Daimler, 

on the other hand, has developed a different system to recover heat from the exhaust gas using an 

electrical generator to provide power to charge a high-voltage battery, where this battery system 

is primarily used to drive a hybrid system. Daimler uses ethanol as the working fluid, similar to 

Volvo’s system. 

Pre-prototype WHR systems have proven to be very efficient under right conditions. In

demonstrations where operation occurred at a single optimal engine operating point, Cummins 

reports potential efficiency gains from WHR on the order of 2.8 percent points from the engine 

without WHR31. Volvo reports around 2.5 percent points33. Daimler reports 2.3 percent 

points.

29

 All of these manufacturers use the type of WHR just described (including both 

mechanisms of mechanical work transfer to crankshaft and electric generator) in vehicle 

demonstrations for the DOE Supertruck program. It is important to note that all of these WHR 

systems are still in the pre-prototype stage of research and development. Despite the promising 

performance of pre-prototype WHR systems, the cost and complexity of these packages from 

Cummins, Volvo and Daimler remain high. The agencies believe manufacturers will improve 

these systems over time just as they have for other advanced technologies that initially had high 

cost and complexity at a comparable stage of development.

The technology also poses issues relating to package size and transient response 

challenges. Thus, the agencies believe that WHR would be less effective in urban traffic and 

would most likely be applied to line haul vehicles, consistent with the technology path on which 

the proposed standards are premised. 

WHR may offer the benefit of replacing the EGR cooler and decrease cooling system 

heat rejection requirements by converting some heat into work. To the extent that WHR systems 

use exhaust heat, they may increase the overall cooling system heat rejection requirement, thus 
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increasing radiator size, which can have negative impacts on cooling fan power needs, as well as 

on vehicle aerodynamics. Significant challenges could arise if the space under the vehicle hood 

happens to be tight, leaving little or no room for increased radiator size, which would necessitate

a redesign of the vehicle front face, sacrificing potential aerodynamic improvements. This issue 

becomes more challenging for those truck cooling systems that are already at cooling capacity

design limits. 

Current pre-prototype systems are heavy, estimated to be on the order of 300-500 lbs 

depending on system design. Without time to optimize designs, any efforts to reduce weight by

simply reducing the size of the key components, such as boilers and condensers, would likely

negatively reduce the system efficiency. However, with enough lead time, the agencies believe 

manufacturers may be able to improve materials and designs to reduce overall system weight 

without compromising efficiency.

Manufacturers have not yet arrived at a consensus on which working fluid(s) to be used 

in WHR systems to balance concerns regarding performance, global warming potential (GWP), 

and safety. Current working fluids have a high GWP (conventional refrigerant), are expensive 

(low GWP refrigerant), are hazardous (ammonia, etc.), are flammable (ethanol/methanol), or can 

freeze (water). One of the challenges is determining how to seal the working fluid properly 

under the vacuum condition with high temperature to avoid safety issues for 

flammable/hazardous working fluids. Addressing leaks would also be an important issue with 

respect to greenhouse gas emission for a high GWP working fluid. Because of these challenges, 

choosing a working fluid will be an important factor for system safety, efficiency, and overall 

production viability. 

Other key challenging issues in the WHR system are its reliability, durability, and market 

acceptance. Durability concerns that have been raised include: boiler fouling and cracking issues 

associated with high thermal gradients, thermal shock, condenser fouling, and various sensor and 

actuator durability under harsh temperature and pressure conditions. It can be reasonably 

estimated that of the current WHR systems under development by the major manufacturers 

consists of at least two hundred parts including all major components, such as expanders, boilers, 

condensers, and fluid pumps, together with many fasteners, wiring cables, sensors, actuators, and 

piping. Determining overall system efficacy and reliability involves rigorous testing in support 

of comprehensive Failure Modes and Effects Analysis (FEMA). These parts, as well as the 

entire WHR system as a whole, must undergo severe winter and summer tests. Multiple trucks 

equipped with the same WHR system must be run on the road, accumulating multiple millions of

miles. During these tests, all failures must be recorded, which are associated with specific failure 

modes or error codes. Root causes must be determined. Warranty costs for each failure mode 

based on the part cost and labor must be assigned. Due to the large number of components of 

WHR, some of the failure modes might not be identified during the road tests even with multiple 

extreme weather tests. It would be a high risk for any manufacturers to put their new technology

into the market without careful WHR system validations and proof of on-the-road tests. 

Similarly, purchasers might be unlikely to risk early adoption of such complex technology if 

deployed prematurely (without substantial testing) due to significant concerns and costs related 

to potential down time. 
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Based on the literature and preceding discussion, WHR technology can be characterized 

as being in the technology demonstration stage for purposes such as the DOE Supertruck 

program. Even though a few trucks with WHR technology have been tested on the road,

33,34,35

many of the components used in the trucks and product-acceptable packaging are still years away

from production. Figure 2-1 shows a generic form of product process flow. As can be seen from 

this figure, it would take 5-15 years from applied research/development to a prototype depending 

on the complexity of the technology. During the prototype stage, all prototype components must 

be available and extensive engine and vehicle tests with WHR must be conducted. The 

production start-up phase would follow. After that, significant efforts must be made from a 

prototype to a commercial product, which typically takes about five years for a complex system 

like WHR. During this approximate five-year period, multiple vehicles should go through all 

weather condition tests, which would help to detect possible failure modes and determine 

warranty cost associated with them. In addition, long lead-time parts and tools should be 

identified; market launch and initial results on operating stability should be completed. 

Furthermore, designs should be released to production, and all product components should be 

available. Finally, production parts on customer fleets and all weather road testing should be 

verified before finally launching production, and distributing parts to the vehicle service network 

for maintenance and repair should be ready.

Figure 2-1 Product Process Flow

The standards the agencies are proposing can provide an effective incentive for 

manufacturers to reach commercial product stage earlier than would otherwise occur. It can 

motivate manufacturers to shorten the period for advancing from a complicated prototype system 

to a commercial product. It can also help to ensure the market penetration after launching a 

product. Nevertheless, in order for WHR to be produced commercially, several things are 

needed. First, it is critical to optimize the WHR package volume, cooling capability, and aero 

drag at typical cruise speeds on highway since the most significant benefits of WHR technology 

would be in line-haul applications. Removal of the exhaust heat exchangers located at the 

exhaust pipe could reduce the total system volume and weight. Working fluids could be selected 

with reasonable low GWP and high performance potential. One approach could be to put a few 

hundred trucks into fleets for trial in the next several years, so that a comprehensive FEMA can 

be thoroughly identified and warranty cost analyses can be more precisely conducted before 
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launching into full volume production. Manufacturers have shown in the past that a robust 

FEMA process can address most problems before a technology is more widely introduced. 

Therefore, the lead time appears to be one of the most noticeable constraints. We believe that all 

the issues and hurdles discussed could be resolved with adequate lead time.

2.4 Technology Principles - Vehicles

2.4.1 Aerodynamics

The aerodynamic efficiency of heavy-duty vehicles has gained increasing interest in 

recent years as fuel prices, competitive freight markets, and overall environmental awareness has 

focused owners and operators on getting as much useful work out of every gallon of diesel fuel 

as possible. Up to 25 percent of the fuel consumed by a line-haul tractor traveling at highway

speeds is used to overcome aerodynamic drag forces, making aerodynamic drag a significant 

contributor to a Class 7 or 8 tractor’s GHG emissions and fuel consumption.36 Because 

aerodynamic drag varies by the square of the vehicle speed, small changes in the tractor 

aerodynamics can have significant impacts on GHG emissions and fuel efficiency of that vehicle. 

With much of their driving at highway speed, the benefits of reduced aerodynamic drag for Class 

7 or 8 tractors can be significant.37

The common measure of aerodynamic efficiency is the coefficient of drag (Cd). The 

aerodynamic drag force (i.e., the force the vehicle must overcome due to air) is a function of the 

Cd, the area presented to the wind (i.e., the projected area perpendicular to the direction of travel 

or frontal area), and the square of the vehicle speed. Cd values for today’s line-haul fleet 

typically range from greater than 0.80 for a classic body tractor to approximately 0.58 for 

tractors that incorporate a full package of widely, commercially available aerodynamic features 

on both the tractor and trailer.

While designers of heavy-duty vehicles and aftermarket products try to aerodynamically

streamline heavy-duty vehicles, there are some challenges. Aerodynamic design must meet 

practical and safety needs such as providing for physical access and visual inspections of vehicle 

equipment. Since weight added to the vehicle can impact its overall fuel efficiency, GHG 

emissions and, in limited cases, the amount of freight the vehicle can carry, aerodynamic design 

and devices must balance the aerodynamic benefit with the contribution to the vehicle weight. In 

addition, aerodynamic designs and devices must balance being as light and streamlined as 

possible with in-use application durability to withstand the rigors a working freight vehicle 

encounters while traveling or loading and unloading. 

However, there are some macro and micro scale techniques that can be employed to 

reduce vehicle drag such as reducing vehicle size, especially, the frontal area; smoothing the 

shape to make it more aerodynamically efficient, thus reducing the Cd; and/or re-directing air to 

prevent entry into areas of high drag (e.g., wheel wells) or to maintain smooth air flow in certain 

areas of the vehicle. Reducing the size of the vehicle can reduce the frontal area; which reduces 

the pressure building up on the lateral surface area exposed to the airflow. Improving the vehicle 

shape may include revising the fore components of the vehicle such as rearward canting/raking 

or smoothing/rounding the edges of the front end components (e.g., bumper, headlights, 

windshield, hood, cab, mirrors) or integrating the components at key interfaces (e.g., 
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windshield/glass to sheet metal) to alleviate fore vehicle drag. Finally, redirecting the air to 

prevent areas of low pressure and slow moving air; thus eliminating areas where air builds 

creating turbulent vortices and increasing drag. Techniques such as blocking gaps in the sheet 

metal, ducting of components, shaping or extending sheet metal to reduce flow separation and 

turbulence are methods being considered to direct air from areas of high drag (e.g., underbody, 

tractor-trailer gap, underbody and/or rear of trailer).

The issue for heavy-duty vehicles is that the cab and/or passenger compartment is 

designed for a specific purpose such as accommodating an inline cylinder engine or allowing for 

clear visibility given the size of the vehicle. Consequently, a reduction in vehicle size and/or 

frontal area may not be realistic for some applications. This also may necessitate an expensive, 

ground-up vehicle redesign and, with a tractor model lifecycle of up to 10 years, may mean that a 

mid-cycle tractor design is not feasible. In addition, the frontal area is also defined by the shape 

behind the cab so reducing just the cab frontal area/size reduction may not be effective. Thus, 

this approach is something that may occur in a long-term timeframe of 10-15 years from today.

Instead, most heavy-duty tractor manufacturers have explored, or are exploring, the latter 

two techniques in the short-term. Compared to previous generation tractors, every high roof 

tractor today has a roof fairing directing air over the top of the cab, fuel tank/chassis fairings that 

prevent side air from flowing underneath the vehicle, and cab side extenders that prevent flow 

from being trapped in the tractor-trailer gap. As a compliance strategy for HD Phase 1, many 

manufacturers refined the aerodynamic shape of their front end components and other 

components (e.g., curving or further extending side extenders) resulting in efficiency difference 

between pre- and post-HD Phase 1, model year tractor aerodynamic performance. Further, 

manufacturers have developed new tractor designs that are taking advantage of sealing gaps in 

sheet metal to redirect the flow and introducing some hard edges to induce turbulent flow on 

certain surfaces to prevent premature flow separation and downstream turbulent flow. For HD 

Phase 2, we anticipate manufacturers would continue to apply these techniques across their 

models and continue to explore refinements and re-designs in other areas of the tractor.

In addition to tractor improvements, there has been growth in the market for trailer 

aerodynamic devices encouraged by our successful SmartWay Partnership and Technology

Verification Program. These devices function similar to components on the tractor by preventing 

air intrusion into areas of the trailer prone to high aerodynamic drag including the tractor-trailer 

gap, the trailer underbody, and the rear of the trailer as shown in Figure 2-2 and Figure 2-3

below. 
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Figure 2-2 Progression of total drag along a typical line-haul tractor-trailer vehicle

Figure 2-3 Low pressure regions contributing to aerodynamic drag along a typical line-haul tractor-trailer 

vehicle

To address this, trailer front/nose devices are being used to round the front end and edges 

of the trailer while also reducing the tractor-trailer gap; skirts on the side of the trailer prevent air 

entering the underside of the trailer and becoming turbulent on the various underbody structure 

components; and trailer aft/rear treatments reduce separation of air flow of the rear edge of the 

trailer to reduce the large wake of turbulent air behind the trailer. Based on current SmartWay

Technology Verification, these devices can reduce fuel consumption from one to nine percent, 

depending on the technology, and if it is employed individually or in combination.

As a result, we believe there is an opportunity within HD Phase 2 to promote continual 

improvement of tractor aerodynamics and capitalize on the potential improvement that 

aerodynamic trailer devices can provide for trailers, and overall combination tractor-trailer 

efficiency.
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2.4.2 Advanced Aerodynamic Concepts

For HD Phase 2, we are proposing standards that would be fully phased in by the 2027

model year. This represents a significant amount of time from today’s action. As such, it is 

possible that by the time the Phase 2 standards are implemented, the state of heavy-duty 

aerodynamic technology and performance may have significantly advanced. Thus, there may be 

a need to have standards to adequately address future tractor-trailer aerodynamic advances. 

Accordingly, we are considering aerodynamic concepts that can achieve aerodynamic 

performance beyond that of the HD Phase 2 aerodynamic standards. There are many approaches 

applicable to today’s tractors and trailers that are not considered in the HD Phase 2 aerodynamic 

standards and advanced research aimed at creating a completely new design paradigm for 

tractor-trailer combinations. 

The advanced aerodynamic standards would not be required but would rather serve as a 

marker for future aerodynamic concepts and/or as a metric for HD Phase 2 advanced/innovative 

aerodynamic technologies. 

2.4.2.1 Aerodynamic Improvements to Current Tractor-Trailer Combinations Based 

on Existing Technology

2.4.2.1.1 Manufacturer Commercial Initiatives

In order to anticipate technology advancement, it is important to benchmark current 

technology improvements based on today’s tractors and trailers. A number of Class 8 tractor

OEM’s have incorporated the technologies requested by their customers to improve fuel 

economy and to meet the HD Phase 1 standards. These technologies include side skirts, boat 

tails and roof fairings as well as some driver monitoring tools. Recently Jack Roberts released 

an article on the internet titled: “Photo, video: Western Star introduces re-designed on-highway

tractor.” 38

Figure 2-4 Pictures of the Western Star Class 8 Tractors

In addition to providing photos and videos of Western Star’s redesigned on-highway

tractor, the article describes a multitude of new features that define the new tractor. These 

features include:
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 A new sweptback four piece bumper with an under bumper valance that contributes 

to aerodynamic efficiency.

 New halogen headlights that are optimized for aerodynamic performance and 

excellent visibility.

 A state-of-the-art visor specifically engineered to work with the impressive slope in 

the hood’s rear air ramp to direct airflow over the cab without an aerodynamic 

penalty.

 Roof and cab fairings that sweep back for tighter trailer gap and help direct air flow 

over and around the trailer.

 Optional chassis side fairings that reduce drag by up to 6 percent while still providing 

easy access to batteries and DEF tank.

 The Western Star Twin Force dual air intake, which feeds a massive centrally

mounted air filter to improve efficiency.

This example demonstrates that manufacturers are continuing to find ways to improve

tractors and are continually exploring concepts, such as those in used in the SuperTruck 

initiative, to improve commercially-available products.

2.4.2.1.2 Supplier Research: SABIC Roof Fairing Technology and 

Manufacturing

Developments in aerodynamics have long been assumed to yield advancements in vehicle 

fuel efficiency. SABIC Innovative Plastics US LLC (SABIC) evaluated a variety of injection 

moldable thermoplastic roof fairing designs for a heavy tractor day cab to quantify efficiencies 

that could be obtained through advanced aerodynamics. Computational Fluid Dynamic (CFD) 

modeling was performed by Exa Corporation, an industry recognized leader in CFD. Multiple 

designs exhibited significant reductions in drag compared to a baseline roof fairing (Figure 1 of 

Figure 2-5). The baseline represented a top performing roof fairing on the market today. The 

best performing SABIC concept (Figure 2) achieved a 5.8 percent reduction in drag and fuel use 

compared to the baseline. Under the well-established 2:1 relationship between delta drag and 

fuel use, the fuel efficiency improved by nearly 3 percent from the baseline design.

The design concept optimized the shape to manage the airflow over the vehicle and 

enable reduced drag and increased fuel economy. Air channels – developed for injection 

molding processes – limit the air stagnation on the front of the trailer as well as accelerate and 

control the direction of the air flow. This innovative concept has been validated using state of 

the art CFD methods. On vehicle tests are suggested to validate findings from these studies. 

(from Matthew D. Marks, Senior Business Manager, Regulatory Automotive and Mass 

Transportation, November 14, 2014).
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Figure 2-5 Surface X-Force (dimensionless) on Baseline and SABIC Concept Roof Fairing

Aerodynamic (surface) force is the force exerted on a body whenever there is a relative 

velocity between the body and the air. These plots represent this force in the direction of the 

vehicle travel at highway speeds. Red indicates a ‘pushing’ of the vehicle rearward, while blue 

indicates a ‘pulling’ of the vehicle forward.

Figure 2-6 SABIC Concept Roof Fairing Operation

We are currently coordinating with SABIC on future efforts to determine feasibility and 

capability of this concept on additional areas of the tractor (e.g., bumper, hood, fuel tank/chassis

skirt fairings, cab side extenders).

2.4.2.1.3 HD Phase 1 Research: External Active Grille Shutter Potential on 

Heavy-Duty Tractors

During HD Phase 1 aerodynamic assessment, we looked at several trends to understand 

some of the aerodynamic trends such as removal of tractor chassis fairings and side extenders, 

different tractor-trailer gap widths, and different trailer leading edge radii. However, one trend 

of particular relevance to advanced aerodynamic improvements for current tractors is the case of 

open versus closed grille. 
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We evaluated the open vs. closed grille trend in the full and reduced scale wind tunnel. 

Below in Figure 3-7 is picture of a 1/8th scale tractor model in the reduced scale wind tunnel with 

the grille covered with aluminum tape to simulate a fully closed grille. 

Figure 2-7 Photo of 1/8th scale model of a tractor with the front, external grille 

covered with aluminum tape to simulate a closed grill configuration.

Below in Table 2-1 and Table 2-2 are the results of our open versus closed grille 

evaluations in the full and reduced scale wind tunnel separately. The tables provide the deltas 

for an open grille CD minus the closed grille CD; where the CDs have been corrected for 

blockage, in the case of the full scale wind tunnel, and normalized for differences in measured 

frontal area between the full and reduced scale wind tunnels using a nominal frontal area of 10.4 

m

2

(111.95 in2). For the full scale wind tunnel, only one tractor OEM was tested. In contrast, for 

the reduced scale wind tunnel, three tractor OEMs were tested.

Table 2-1 Full Scale Wind Tunnel Results for Open verses Close Grille Configurations

TRACTOR 

MODEL

DELTA WACD

@55MPH

% DELTA CD VS. OPEN GRILLE 

CD

1 0.003 0.60%

Table 2-2 Reduced Scale Wind Tunnel Results for Open versus Close Grille Configurations

TRACTOR 

MODEL

DELTA WACD 

@55MPH

% DELTA CD VS. OPEN GRILLE 

CD

A 0.010 1.69%

B 0.012 1.89%

C 0.009 1.45%

Based on the data in these tables, there is a potential wind-average drag improvement of 

0.6 percent to 1.45 percent from closing off the external, front grille of the tractor. This indicates 

the potential of active grille shutter systems on heavy-duty tractors. These systems are currently 

being applied on light duty vehicles behind the external grille to improve aerodynamics. 
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However, a recent SAE paper determined that the optimal position for active grille shutter 

systems was the external grille flush with the vehicle sheet metal.39 This technique could be 

implemented on the external grille designs for current-design, heavy-duty tractors as well.

2.4.2.1.4 National Research Council of Canada Historical Research on 

Improving Heavy-Duty Tractors

The National Research Council of Canada (NRC-Can) performed an assessment of the 

drag benefit or detriment of various tractor components40 and found the following in Table 2-3.

Table 2-3 Reduced Scale Wind Tunnel Results for Open versus Close Grille Configurations

COMPONENT DELTA 

WACD

OEM Side Mirrors -0.0156

OEM Fender Mirrors -0.0098

Wheel Covers (Tractor and Trailer) 0.0020

Tractor Drive Axle Wrap-Around Splash Guards 0.0049

Roof Fairing Rear-Edge Filler 0.0137

Based on this table, there is the potential to improve tractor aerodynamics by 206 counts 

(0.0206 WACD) with the addition of wheel covers, drive axle wrap around splash guards, and 

roof fairing rear edge filler, and up to 460 counts (0.0460) if the OEM side and fender mirrors 

are replaced with a camera system, as suggested by the study, and combined with the wheel 

covers, drive axle wrap around splash guards, and roof fairing rear edge filler. Therefore, 

considering the current wind-average drag performance of current heavy-duty tractors, this study

demonstrates the possibility to improve tractors an additional ~1 percent with some simple 

changes.

2.4.2.2 Aerodynamic Improvements to Current Tractor-Trailer Combinations Based 

on Complete Vehicle Redesign

This section contains summaries of ongoing work from various DOE efforts as well as 

individual efforts such as Airflow Truck Company to develop improved aerodynamic Class 8

vehicles. In addition to aerodynamics, there are other technologies such as driver awareness and 

ability to drive for maximum fuel economy with increased aerodynamics. Overall it is expected 

that the research being performed over the next year or two will reveal drastic improvements in 

CdA and fuel economy. DOE’s Lawrence Livermore National Laboratory is also looking at the 

aerodynamics of tankers.

2.4.2.2.1 Collaborative, Government-Industry Advanced Aerodynamic 

Research: SuperTruck Program

DOE’s SuperTruck project is one of several initiatives that are part of the 21st Century Truck 

Partnership. The partnership is a public-private initiative to stimulate innovation in the trucking 

industry through sponsorship from government agencies, companies, national laboratories and 

universities. DOE’s Vehicle Technologies Program provided matching funds to the program. 
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Cummins, Peterbilt and their program partners invested $38.8 million in private funds for the 

first four years of the project with additional funding provided for future research beyond 2014.

The goal of the SuperTruck Initiative was to develop a tractor that could meet or exceed 

10 mpg – where tractors at this point are averaging between 5.5 and 6.5 mpg. Advances in 

engines, aerodynamics and more helped the tractor project increase its fuel economy. The 

SuperTruck objectives included development and demonstration of a highly efficient and clean 

diesel engine, an advanced waste heat recovery system, an aerodynamic tractor and trailer 

combination and a lithium ion battery auxiliary power unit, to reduce engine idling. Eaton Corp, 

also part of the Cummins-Peterbilt SuperTruck project team, contributed technologies including 

the design, development and prototyping of an advanced automated transmission that facilitated 

reduced engine-operating speeds. Cummins and Eaton jointly designed shift schedules and other 

features to yield further improved fuel efficiency.

Details of the SuperTruck that achieved 10.7 mpg are in video on the todaystrucking.com 

website and are presented in four videos.41 Aerodynamic features of the tractor include the 

following: airflow into the engine compartment (through the front bumper, through the radiator 

and under the vehicle), less clearance between the road and the bottom of the tractor (rubber skirt 

under steps), close gaps on tractor/trailer (between hood and bumper, etc.), minimized gap 

between the trailer and tractor with a ball and socket design, full trailer skirt, roof fairing, smaller 

mirrors, minimized gap between wheels and wheel wells, wheel covers, boat tail, air foil on rear 

bumper design, single wide tires, and perforated mud flaps that allow air to bypass through them 

and reduce drag. A picture of this truck based on a Peterbilt tractor is shown in Figure 2-7

below. 

Even with the addition of these aerodynamic features, overall the tractor mass was 

reduced by over 1,300 lbs. The article states that the CFD analysis of the tractor showed a 50

percent reduction in drag and with a 2:1 drag reduction the aero improvements resulted in a 25

percent improvement in fuel economy. In the 300 mile test course shown on the video, it was 

stated that the tractor achieved 10.7-11.1 mpg. 

Figure 2-7 Peterbilt SuperTruck Concept (Picture from: http://www.peterbilt.com/about/media/2014/396/)

This effort represents the first step in the evolution of improving the aerodynamic 

efficiency of tractor-trailer by radically redesigning today’s tractor-trailer combination, as a 

wholly integrated system rather each component, tractor and trailer, independently.
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2.4.2.2.2 Government Sponsored Advanced Aerodynamic Research: 

Lawrence Livermore National Laboratory

Lawrence Livermore National Laboratory’s (LLNL) Kambiz Salari presented 

information at the 2014 DOE Annual Merit Review on “DOE’s Effort to Improve Heavy Duty 

Vehicle Fuel Efficiency through Improved Aerodynamics”. A joint project with Wabash, 

Navistar, Michelin, Safeway, Frito Lay, Praxair, Freight Wing Inc, ATDynamics, Kentucky 

Trailer and Spirit with funding for work in 2013 and 2014, the objective was to develop a new 

integrated tractor-trailer design from ground up by: first, designing the first generation of an 

integrated tractor-trailer geometry called Generic Speed Form one (GSF1); and second 

performing wind tunnel tests of selected aero devices for tractor-trailers and tankers to improve 

fuel efficiency. The goal was to reduce aerodynamic drag of Class 8 tractor-trailers by 

approximately 25 percent leading to a 10-15 percent increase in fuel efficiency at 65 mph. In 

addition, the group developed an aerodynamic tractor-trailer prototype designed to achieve 50

percent reduced aerodynamic drag as shown in Figure 2-8. This effort represents the next 

generation of tractors and trailers: a completely redesigned, fully integrated, optimized shape for 

the tractor-trailer combination.

Figure 2-8 Pictures showing future heavy-duty tractor trailer concept to achieve >50% aerodynamic 

improvement for Class 8 line haul heavy-duty vehicles

2.4.2.2.3 Independent Advanced Aerodynamic Research: Airflow Truck 

Company Bullet Truck Concept 

In addition to the work being performed by the OEMs and consortiums mentioned above, 

there are also independent commercial initiatives underway to radically redesign the tractortrailer combination similar to the concept by Lawrence Livermore National Laboratories 

discussed above. 

The Class 8 tractor and trailer modifications in Figure 2-9 were designed, built, and tested 

in 2012 by Mr. Robert Sliwa of the Airflow Truck Company. Mr. Sliwa built his first 

aerodynamic tractor in the 1983 when he was an owner-operator. After that, Mr. Sliwa became 
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interested in computers and used his computer background along with his truck driver and race 

car driver experience to create the Bullet Truck. His current design is described at 

www.airflowtruck.com and his tractor design modifications are similar in appearance to the 

bullet looking trains used in Europe. The tractor uses a 1999 engine and the test was conducted 

in the manner in which the tractor was driven at 55 mph by an experienced driver throughout its 

test while loaded at 65,000 lbs from Newington, Connecticut to Tracy, California.

The website shows that the vehicle achieved 13.4 mpg during this trip and included 

traveling through the Rocky Mountains. CFD analyses of the design after the vehicle was built

found a modest decrease in CdA, thus giving credence to the design work under the hood (most 

of which are outlined at airflowtruck.com) and driving techniques. Several new technologies 

were developed during this work which included retractable tractor steps, all electric air 

conditioning, crankshaft mounted cooling fan, computer-controlled fan hub, waterless engine 

coolant, reduced engine parasitic losses, full tractor and trailer side skirts, 4 axle ATIS, and an 

engine feedback information display.

Figure 2-9 Figure of the Bullet Truck by Airflow Truck Company9

Another prototype is in development and it will include further aerodynamic optimization 

of the tractor and trailer, and the combination thereof, as well as the addition of a boat tail. 

These technologies and more are expected to result in higher mpg under similar test conditions. 

Other changes in the vehicle makeup and test would include a more modern engine and testing at 

higher speeds (>55 mpg (60-65mpg)) may influence the end results.
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Figure 2-10 Figure of a Highly Aerodynamic Concept Class 8 Tractor

Although it is difficult to separate the aerodynamic factors from the engine and 

operational factors that lead to the claimed 13.4 mpg, the designs being explored and built by

Mr. Sliwa are indicative of the type of tractor-trailer combinations we anticipate will be built in 

the future.

2.4.3 Tires

2.4.3.1 Improved Rolling Resistance

Research indicates that a tire’s contribution to overall vehicle fuel efficiency is 

approximately proportional to the vehicle weight on it.

42

 Energy loss associated with tires is 

mainly due to deformation of the tires under the load of the vehicle, known as hysteresis, but 

smaller losses result from aerodynamic drag, and other friction forces between the tire and road 

surface and the tire and wheel rim. Collectively the forces that result in energy loss from the 

tires are referred to as rolling resistance. Tires with higher rolling resistance lose more energy, 

thus using more fuel and producing more CO2 emissions in operation, while tires with lower 

rolling resistance lose less energy, and use less fuel and produce less CO2 emissions in operation.

A tire’s rolling resistance is a factor considered in the design of the tire, and is affected by 

the tread and casing compound materials, the architecture of the casing, tread design, and the tire 

manufacturing process. It is estimated that 35 to 50 percent of a tire’s rolling resistance is from 

the tread and the other 50 to 65 percent is from the casing.42 Tire inflation can also impact 

rolling resistance in that under-inflated tires can result in increased deformation and contact with 

the road surface. In addition to the effect on CO2 emissions and fuel consumption, these design 

and use characteristics of tires also influence durability, traction (both wet and dry grip), vehicle 

handling, ride comfort, and noise. Tires that have higher rolling resistance are likely designed to 

address one or more of these other tire attributes.

EPA’s SmartWay program identified test methods and established criteria to designate 

certain tires as having lower rolling resistance (LRR) for use in the program’s emissions tracking 

system, verification program, and SmartWay vehicle specifications. To measure a tire’s 

efficiency, the vertical load supported by the tire must be considered, because rolling resistance 

is a function of the load on a tire. EPA uses a tire’s rolling resistance coefficient (CRR) to 

characterize LRR tires. CRR is measured using the ISO 28850 test method (see 40 CFR 

1037.520(c),) and reported as the rolling resistance force over vertical load (kg/metric ton). 

Differences in rolling resistance of up to 50 percent have been identified for tires designed to

equip the same vehicle.43 
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LRR tires are commercially available from most tire manufacturers and can be applied to 

vehicles in all MD/HD classes. According to an energy audit conducted by Argonne National 

Lab, tires were shown to be the second largest contributor to energy losses for a Class 6 delivery

truck at 50 percent load and speeds up to 35 mph (a typical average speed of urban delivery

vehicles).

44

 For Class 8 tractor-trailers, the share of vehicle energy required to overcome rolling 

resistance is estimated at nearly 13 percent.45 

NHTSA, EPA, and ARB met with stakeholders from the tire industry (Bridgestone, 

Continental, Cooper, Goodyear, and Michelin) in 2014 to discuss the next generation of LRR 

tires for the Phase 2 timeframe for all segments of Class 2b-8 vehicles, including trailers. 

Manufacturers discussed forecasts for rolling resistance levels and production availability in the 

Phase 2 timeframe, as well as their plans for improving rolling resistance performance while 

maintaining other performance parameters such as traction, handling, wear, mass reduction, 

retreadability, and structural durability. 

The meetings included specific discussions of the impacts of the current generation of 

LRR tires on vehicle stopping distance and handling. Manufacturers indicated no known safety 

disbenefit in the current on-road fleet from use of LRR tires. While the next generation of tires 

may require some tradeoffs in wear performance and costs over the next 10 years to achieve 

better tire rolling resistance performance, manufacturers said they will not trade off safety for 

performance. They also emphasized that keeping tires inflated (through proper maintenance or 

automatic systems) was the best way to assure long term fuel efficiency and safety during 

vehicle operation.

2.4.3.2 Wide Base Singles

Low rolling resistance tires can be offered for dual assembly tires and as wide base 

singles (WBS). Wide base singles are primarily intended for combination tractor-trailers, but 

some vocational vehicles are able to accommodate them. In the early years of this technology, 

some states and local governments restricted use of WBS, but many of these restrictions have 

since been lifted. As of December 2010, NACFE reports that there is virtual acceptance in North 

America with only a few provinces in Canada that disallow or require special permitting for the use 

of wide base tires.

46

 A wide base single is a larger tire with a lower profile. The common wide 

base single sizes include 385/65R22.5, 425/65R22.5, 445/65R22.5, 435/50R22.5 and 

445/50R22.5. Generally, a wide base single tire has less sidewall flexing compared to a dual 

assembly and therefore less hysteresis occurs. Compared to a dual tire assembly, wide base 

singles also produce less aerodynamic resistance or drag. Wide base singles can contribute to 

improving a vehicle’s fuel efficiency through design as a low rolling resistance tire and/or 

through vehicle weight reduction. 

According to one study, the use of fuel efficient wide base singles can reduce rolling 

resistance by 3.7 to 4.9 percent compared to the most equivalent dual tire.47 An EPA study with 

a tractor-trailer demonstrated an improvement in fuel consumption of 6 percent at 55 mph on the 

highway, 13 percent at 65 mph on the highway and 10 percent on a suburban loop48 using wide 

base singles on the drive and trailer axles. EPA attributed the fuel consumption improvement to 

the reduction in rolling resistance and vehicle weight reduction from using wide base singles. In 

2008 the Department of Energy (DOE) compared the effect of different combinations of tires on 
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the fuel efficiency of Class 8 tractors. The data collected based on field testing indicates that 

tractors equipped with wide base singles on the drive axle experience better fuel efficiency than 

tractors equipped with dual tires, independent of the type of tire on the trailer.49 This study in 

particular indicated a 6.2 percent improvement in fuel efficiency from wide base singles.

There is also a weight savings associated with wide base singles compared to dual tires. 

Wide base singles can reduce a tractor and trailer’s weight by as much as 1,000 lbs. when 

combined with aluminum wheels. Bulk haulers of gasoline and other liquids recognize the 

immediate advantage in carrying capacity provided by the reduction in the weight of tires and 

have led the transportation industry in retrofitting their tractors and trailers50.

New generation wide base singles, which were first introduced in 2000, are designed to 

replace a set of dual tires on the drive and/or trailer positions. They are designed to be 

interchangeable with the dual tires without any change to the vehicle51. If the vehicle does not 

have hub-piloted wheels, there may be a need to retrofit axle components.

50, 52

 In addition to 

consideration of hub / bearing / axle, other axle-end components may be affected by use of wide 

base singles. To assure successful operation, suitable components should be fitted as 

recommended by the vehicle manufacturer.

53

Current wide base singles are wider than earlier models and legal in all 50 states for a 5-

axle, 80,000 GVWR truck47. Wide base singles meet the “inch-width” requirements nationwide, 

but are restricted in certain states up to 17,500 lbs. on a single axle at 500 lbs/inch width limit, 

and are not allowed on single axle positions on certain double and triple combination vehicles51. 

An inch-width law regulates the maximum load that a tire can carry as a function of the tire 

width. Typically wide base singles are optimized for highway operation and not for city or 

on/off highway operation. However, newer wide base singles are being designed for better scrub 

resistance, which would allow an expansion of their use. The current market share of wide base 

singles in combination tractor applications is 5 percent and the potential market is all 

combination tractors.47 New generation wide base singles represent an estimated 0.5 percent of 

the 17.5 million tires sold each year in the U.S.51

2.4.3.3 Tire Pressure Systems

Proper tire inflation is critical to maintaining proper stress distribution in the tire, which 

reduces heat loss and rolling resistance. Tires with reduced inflation pressure exhibit more 

sidewall flexing and tread shearing, resulting in greater rolling resistance than a tire operating at 

its optimal inflation pressure. Bridgestone tested the effect of inflation pressure and found a 2 

percent variation in fuel consumption over a 40 psi range.42 Tractor-trailers operating with all 

tires under-inflated by 10 psi have been shown to increase fuel consumed by up to 1 percent.54 

Tires can gradually lose pressure from small punctures, leaky valves or simply diffusion through 

the tire casing. Changes in ambient temperature can also have an effect on tire pressure. Trailers 

that remain unused for long periods of time between hauls may experience any of these 

conditions. To achieve the intended fuel efficiency benefits of low rolling resistance tires, it is 

critical that tires are maintained at the proper inflation pressure. 

Although most truck fleets understand the importance of keeping tires properly inflated, 

it is likely that a substantial proportion of trucks on the road have one or more underinflated tires. 
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An industry survey conducted in 2002 at two truck stops found that fewer than half of the tires 

checked were within 5 pounds per square inch (psi) of their recommended inflation pressure. 

Twenty-two percent of the vehicles checked had at least one tire underinflated by at least 20 psi, 

and 4 percent of the vehicles were running with at least one flat tire, defined as a tire 

underinflated by 50 psi or more. The survey also found mismatches in tire pressure exceeding 5

percent for dual tires on axle ends.55

A commercial vehicle tire condition study conducted by the Federal Motor Carrier Safety 

Administration (FMCSA) in 2003 found similar indicators of poor tire inflation pressure 

maintenance in commercial fleets. The FMCSA concluded that only 44 percent of all tires on 

commercial vehicles were inflated within 5 psi of the recommended pressure, while over 7

percent of all tires in operation on commercial vehicles were underinflated by at least 20 psi. It

was also determined that the rates of tires used in dual assemblies that differed in pressure by 

more than 5 psi was approximately 20 percent for tractor duals and 25 percent for trailer duals. 

Finally, the FMCSA concluded that there were significant differences in tire inflation 

maintenance practices between private and for-hire fleets, smaller and larger fleets, and local bus 

and motor coach fleets.56

If drivers or fleets are not diligent about checking and attending to under-inflated tires, 

the trailer may have much higher rolling resistance and much higher CO2 emissions and fuel 

consumption. Proper tire inflation pressure can be maintained with a rigorous tire inspection and 

maintenance program and EPA provides information on proper tire inflation pressure through its

SmartWay program.

57

 Tire pressure monitoring (TPM) and automatic tire inflation (ATI) 

systems are designed to address under-inflated tires. Both systems alert drivers if a tire’s 

pressure drops below its set point. TPM systems monitor the tires and require user-interaction to 

reinflate to the appropriate pressure. Yet unless the vehicle experiences a catastrophic tire 

failure, simply alerting the driver that a tire’s pressure is low may not necessarily result in action 

to correct the problem. A driver may continue driving to their final destination before addressing 

the tires, resulting in many miles of driving with improperly inflated tires. Current ATI systems 

take advantage of trailers’ air brake systems to supply air back into the tires (continuously or on

demand) until a selected pressure is achieved. In the event of a slow leak, ATI systems have the 

added benefit of maintaining enough pressure to allow the driver to get to a safe stopping area.58 

The agencies believe TPM systems cannot sufficiently guarantee the proper inflation of tires due 

to the inherent user-interaction required. Therefore, ATI systems are the only pressure systems 

the agencies are proposing to recognize in GEM. 

Estimates of the benefits of ATI systems vary depending on the base level of 

maintenance already performed by the driver or fleet, as well as the number of miles the trailer 

travels. Vehicles that are well maintained or that travel fewer miles would experience less 

benefits from ATI systems compared to vehicles that log many miles or have a history of driving 

with poorly inflated tires. The agencies believe ATI systems can provide a CO2 and fuel 

consumption benefit to most tractors and trailers. Drivers and fleets that diligently maintain their 

tires will spend less time and money to inspect each tire knowing that they are properly inflated. 

Vehicles that have lower annual VMT due to long periods between uses would be less 

susceptible to low tire pressures when they resume activity. Vehicles with high annual VMT 

would experience the fuel savings associated with consistent tire pressures. 
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2.4.3.4 Retreaded Tires

The tread life of a tire is a measure of durability and some tires are designed specifically 

for greater durability. Commercial vehicle tires are designed to be retreaded, a process in which 

a new tread is bonded to the tire casing. The original tread of a tire will last anywhere from 

100,000 miles to over 300,000 miles, depending on vehicle operation, original tread depth, tire 

axle position, and proper tire maintenance. Retreading can extend the tire’s useful life by

100,000 miles or more.59 In 2005, the Tire Industry Association estimated that approximately

17.6 million retreaded truck tires were sold in North America60.

All of the top commercial vehicle tire manufacturers are involved in tire retread 

manufacturing. Bridgestone Bandag Tire Solutions accounts for 42 percent of the domestic 

retreaded vehicle tire market with its Bandag retread products; Goodyear Tire and Rubber 

Company accounts for 28 percent, mostly through its Wingfoot Commercial Tire Systems; 

Michelin Retread Technologies Incorporated, with Megamile, Oliver, and Michelin retread 

products, accounts for 23 percent. Other tire companies like Continental and independent retread 

suppliers like Marangoni Tread North America (which also produces the Continental 

“ContiTread” retread product) make up the remaining 7 percent.61 The retreading industry itself 

consists of hundreds of retreaders who sell and service retreaded tires, often (but not always) 

using machinery and practices identified with one of the major retread producers. There are 

about 800 retread plants in North America.62 The top 100 retreaders in the U.S. retread 47,473 

truck tires per day.

To maintain the quality of the casing and increase the likelihood of retreading, a tire 

should be retreaded before the tread depth is reduced to its legal limit. At any time, steer tires

must have a tread depth of at least 4/32 of an inch and other tires, including drive tires and trailer 

tires, must have a tread depth of at least 2/32 of an inch (49 CFR § 393.75). Trucking fleets 

often retread tires before tire treads reach this minimum depth in order to preserve the integrity

of the tire casing for retreading. If the casing remains in good condition, a truck tire can be 

safely retreaded multiple times. Heavy truck tires in line haul operation can be retread 2 to 3 

times and medium-duty truck tires in urban use can be retread 5 or more times.63 To 

accommodate this practice, many commercial vehicle tire manufacturers warranty their casings 

for up to five years, excluding damage from road hazards or improper maintenance.

To protect the casing, a steer tire is generally retreaded once the tread is worn down to 

6/32 of an inch and a drive tire is retreaded once the tread is worn down to 8/32 of an inch.64 

Tires used on Class 8 vehicles are retreaded as many as three times. 

Both the casing and the tread contribute to a tire’s rolling resistance. It is estimated that 

35 to 50 percent of a tire’s rolling resistance is the result of the tread. Differences in drive tire 

rolling resistance of up to 50 percent for the same casing with various tread compounds have 

been demonstrated. For example, a fuel efficient tread (as defined by the manufacturer) was 

added to two different casings resulting in an average increase in rolling resistance of 48 percent. 

When a nonfuel efficient tread (also defined by the manufacturer) was added to the same casings, 

the rolling resistance increased by 125 percent on average. This characterizes the effect of the 

tread on the rolling resistance of a tire. 
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Because tires can be retreaded multiple times, changes in the casing due to wear, damage 

and material aging may impact rolling resistance to a greater degree than would occur in an 

original tire. Additionally, as evidenced above, if a tread compound different than the original 

tread is used, a retreaded tire can have higher or lower rolling resistance than the original tire. 

Since the agencies have no way of knowing whether the rolling resistance of retreaded tires will 

be higher or lower than the rolling resistance of the original tires, we similarly have no way of 

knowing whether low rolling resistance tire benefits will continue to accrue for a vehicle’s entire 

lifetime. 

2.4.4 Transmissions

Transmissions are a significant vehicle component. They are part of the drive train, 

which also includes axles and tires. Ways to improve transmissions include shift strategy, gear 

efficiency, gear ratios, etc. The relative importance of having an efficient transmission increases 

when vehicles operate in conditions with a higher shift density. Each shift represents an 

opportunity to lose speed or power that would have to be regained after the shift is completed. 

Further, each shift engages gears that have their own inherent inefficiencies.

Optimization of vehicle gearing to engine performance through selection of transmission 

gear ratios, final drive gear ratios and tire size can play a significant role in reducing fuel 

consumption and GHGs. Optimization of gear selection versus vehicle and engine speed 

accomplished through driver training or automated transmission gear selection can provide 

additional reductions. The 2010 NAS report found that the opportunities to reduce fuel 

consumption in heavy-duty vehicles due to transmission and driveline technologies in the 2015 

time frame ranged between 2 and 8 percent.65

The design goal is for the transmission to deliver the needed power to the vehicle while 

maintaining engine operation within the engine’s “sweet spot” for most efficient operation. 

Truck and chassis manufacturers today offer a wide range of tire sizes, final gear ratios and 

transmission choices so that owners can work with application engineers to specify an optimal 

combination given the intended vehicle service class and other performance needs. 

2.4.4.1 Optimizing Number of Gears and Gear Ratios

Manufacturers can choose to replace 6-speed transmissions with 8-speed or more

automatic transmissions. Additional ratios allow for further optimization of engine operation 

over a wider range of conditions, but this is subject to diminishing returns as the number of 

speeds increases. As additional planetary gear sets are added (which may be necessary in some 

cases to achieve the higher number of ratios), additional weight and friction are introduced. 

Also, the additional shifting of such a transmission can be perceived as bothersome to some 

consumers, so manufacturers need to develop strategies for smooth shifts. 

The Phase 1 rulemaking projected that 8-speed transmissions could incrementally reduce 

fuel consumption by 1 to 3 percent from a baseline 6-speed automatic transmission over some 

test cycles. The SwRI report uses 2 to 3 percent fuel consumption reduction when replacing 6-

speed baseline automatic transmissions with improved 8-speed automatic transmissions. 
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2.4.4.2 Gear Efficiencies

As described elsewhere for axles and engines, the efficiency of gears can be improved by

reducing friction and minimizing mechanical losses. This can be done by reducing the friction 

between the two gears in contact. This friction is reduced mainly by improving the surface finish 

of the gears. The other way of doing is by reducing the amount of distance the gear faces are 

sliding against each other.

2.4.4.3 Shift Strategies

Calibrating the transmission shift schedule to upshift earlier and quicker, and to lock up 

or partially lock up the torque converter under a broader range of operating conditions can 

reduce fuel consumption and CO2 emissions. However, this operation can result in a perceptible 

degradation in noise, vibration, and harshness. The degree to which NVH can be degraded 

before it becomes noticeable to the driver is strongly influenced by characteristics of the vehicle, 

and although it is somewhat subjective, it always places a limit on how much fuel consumption 

can be improved by transmission control changes.

During operation, an automatic transmission’s controller manages the operation of the 

transmission by scheduling the upshift or downshift, and locking or allowing the torque 

converter to slip based on a preprogrammed shift schedule. The shift schedule contains a 

number of lookup table functions, which define the shift points and torque converter lockup 

based on vehicle speed and throttle position, and other parameters such as temperature. 

Aggressive shift logic can be employed in such a way as to maximize fuel efficiency by 

modifying the shift schedule to upshift earlier and inhibit downshifts under some conditions, 

which reduces engine pumping losses and engine friction. The application of this technology

does require a manufacturer to confirm that drivability, durability, and NVH are not significantly 

degraded. 

A torque converter is a fluid coupling located between the engine and transmission in 

vehicles with automatic transmissions and continuously-variable transmissions (CVT). This 

fluid coupling allows for slip so the engine can run while the vehicle is idling in gear (as at a stop 

light), provides for smoothness of the powertrain, and also provides for torque multiplication 

during acceleration, and especially launch. During light acceleration and cruising, the inherent 

slip in a torque converter causes increased fuel consumption, so modern automatic transmissions 

utilize a clutch in the torque converter to lock it and prevent this slippage. Fuel consumption can 

be further reduced by locking up the torque converter at lower vehicle speeds, provided there is 

sufficient power to propel the vehicle, and noise and vibration are not excessive. If the torque 

converter cannot be fully locked up for maximum efficiency, a partial lockup strategy can be 

employed to reduce slippage. Early torque converter lockup is applicable to all vehicle types 

with automatic transmissions. Some torque converters would require upgraded clutch materials 

to withstand additional loading and the slipping conditions during partial lock-up. As with 

aggressive shift logic, confirmation of acceptable drivability, performance, durability and NVH 

characteristics would be required to successfully implement this technology.
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2.4.4.4 Architectures

The manual transmission architecture has traditionally been considered the most efficient 

architecture since it did not experience the losses inherent in a torque converter required on a 

traditional automatic transmission (a traditional automatic transmission being a transmission with 

fully automated shifting and using a hydraulic lock-up torque converter for smooth vehicle 

launching from a stop). However, this traditional understanding has been called into question as 

advances in electronics and computer processing power allow for more efficiency from a manual 

transmission architecture with fully automated shifting. The two primary manual transmission 

architectures employing automated shifting are the automated manual transmission (AMT) and 

the dual-clutch transmission (DCT). When implemented well, these mechanically more efficient 

designs could inherently provide better fuel efficiency and lower greenhouse gas emissions than 

conventional torque converter automatic transmission designs and, potentially, even fully manual 

transmissions. These transmissions offer the inherently lower losses of a manual transmission 

with the efficiency and shift quality advantages of electronic controls. The lower losses stem 

from the elimination of the conventional lock-up torque converter, and a greatly reduced need for 

high pressure hydraulic circuits to hold clutches to maintain gear ratios (in automatic 

transmissions).

2.4.4.4.1 AMT

An AMT is mechanically similar to a conventional manual transmission, but shifting and 

launch functions are automatically controlled by electronics. The term AMT generally refers to 

a single clutch design (differentiating it from a dual-clutch transmission, or dual-clutch AMT, 

described below) which is essentially a manual transmission with automated clutch and shifting. 

Because of shift quality issues with single-clutch designs, dual-clutch designs are more common 

in light-duty applications where driver acceptance is of primary importance. In the HD sector, 

shift quality remains important but is less so when compared to light-duty. As a result, the 

single-clutch AMT architecture can be an attractive technology for HD vehicles. 

2.4.4.4.2 DCT

A DCT uses separate clutches (and separate gear shafts) for the even-numbered and the 

odd-numbered gears. In this way, the next expected gear is pre-selected thereby allowing for 

faster and smoother shifting. For example, in a 6 speed DCT, if the vehicle is accelerating in 

third gear, the shaft with gears one, three and five has gear three engaged and is transmitting 

power to the wheels. The shaft with gears two, four, and six is idle but has gear four engaged. 

When a shift is required, the controller disengages the odd-gear clutch while simultaneously

engaging the even-gear clutch, thus making a smooth shift. If, on the other hand, the driver 

slows the vehicle instead of continuing to accelerate, the transmission would have to change to 

second gear on the idling shaft to anticipate a downshift. This shift can be made quickly on the 

idling shaft since there is no torque being transferred on it.

There are variations of the DCT design, with some having wet clutches and some dry

clutches, and more recent versions that incorporate a torque converter similar to but smaller than 

the torque converter of a traditional automatic transmission. The wet clutch designs offer a 

higher torque capacity that comes from the use of a hydraulic system that cools the clutches. Wet 
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clutch systems are also less efficient than dry clutch systems due to the losses associated with the 

hydraulic pumping. They also are more costly due to the hydraulics. 

2.4.4.5 Hybrid Powertrain Systems

The industry is currently developing many variations of hybrid powertrain systems. The 

hybrids developed to date have seen fuel consumption and CO2 emissions reductions between 20 

and 50 percent in the field. However, there are still some key issues that are restricting the 

penetration of hybrids, including overall system cost, battery technology, and lack of costeffective electrified accessories.

A hybrid vehicle is a vehicle that combines two significant sources of propulsion energy, 

where one uses a consumable fuel (like diesel), and one is rechargeable (during operation, or by 

another energy source). Hybrid technology is well established in the U.S. light-duty market, 

some manufacturers have been producing heavy-duty hybrid models for many years, and others 

are looking to develop hybrid models in future years. 

Hybrids reduce fuel consumption through three major mechanisms:

• The internal combustion engine can be optimized (through downsizing, modifying 

the operating cycle, or other control techniques) to operate at or near its most efficient point 

more of the time. Power loss from engine downsizing can be mitigated by employing power 

assist from the secondary power source.

• Some of the energy normally lost as heat while braking can be captured and 

stored in the energy storage system for later use.

• The engine is turned off when it is not needed, such as when the vehicle is 

coasting or when stopped.

Hybrid vehicles utilize some combination of the three above mechanisms to reduce fuel 

consumption and CO2 emissions. The effectiveness of fuel consumption and CO2 reduction 

depends on the utilization of the above mechanisms and how aggressively they are pursued. One 

area where this variation is particularly prevalent is in the choice of engine size and its effect on 

balancing fuel economy and performance. Some manufacturers choose not to downsize the 

engine when applying hybrid technologies. In these cases, performance is vastly improved, 

while fuel efficiency improves significantly less than if the engine were downsized to maintain 

the same performance as the conventional version. The non-downsizing approach is used for 

vehicles where towing and/or hauling are an integral part of their performance requirements. In 

these cases, if the engine is downsized, the battery can be quickly drained during a long hill 

climb with a heavy load, leaving only a downsized engine to carry the entire load. Because 

towing capability is currently a heavily-marketed HD pickup truck attribute, manufacturers are 

hesitant to offer a truck with a downsized engine that can lead to a significantly diminished 

towing performance when the battery state of charge level is low, and therefore engines are 

traditionally not downsized for these vehicles.
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Strong hybrid technology utilizes an axial electric motor connected to the transmission 

input shaft and connected to the engine crankshaft through a clutch. The axial motor is a

motor/generator that can provide sufficient torque for launch assist, all electric operation, and the 

ability to recover significant levels of braking energy.

A hybrid drive unit is complex and consists of discrete components such as the electric 

traction motor, transmission, generator, inverter, controller and cooling devices. Certain types of 

drive units may work better than others for specific vehicle applications or performance 

requirements. Several types of motors and generators have been developed for hybrid-electric 

drive systems, many of which merit further evaluation and development on specific applications. 

Series HEVs typically have larger motors with higher power ratings because the motor alone 

propels the vehicle, which may be applicable to Class 3-5 applications. In parallel hybrids, the 

power plant and the motor combine to propel the vehicle. Motor and engine torque are usually 

blended through couplings, planetary gear sets and clutch/brake units. The same mechanical 

components that make parallel heavy-duty hybrid drive units possible can be designed into series 

hybrid drive units to decrease the size of the electric motor(s) and power electronics.

An electrical energy storage system is needed to capture energy from the generator, to 

store energy captured during vehicle braking events, and to return energy when the driver 

demands power. This technology has seen a tremendous amount of improvement over the last 

decade and recent years. Advanced battery technologies and other types of energy storage are 

emerging to give the vehicle its needed performance and efficiency gains while still providing a 

product with long life. The focus on the more promising energy storage technologies such as 

nickel metal-hydride (NiMH) and lithium technology batteries along with ultra-capacitors for the 

heavy-duty fleet should yield interesting results after further research and applications in the 

light-duty fleet.

Heavy-duty hybrid vehicles also use regenerative braking for improved fuel economy, 

emissions, brake heat, and wear. A conventional heavy vehicle relies on friction brakes at the 

wheels, sometimes combined with an optional engine retarder or driveline retarder to reduce 

vehicle speed. During normal braking, the vehicle’s kinetic energy is wasted when it is 

converted to heat by the friction brakes. The conventional brake configuration has large 

components, heavy brake heat sinks, and high temperatures at the wheels during braking, audible 

brake squeal, and consumable components requiring maintenance and replacement. Hybrid 

electric systems recover some of the vehicle’s kinetic energy through regenerative braking, 

where kinetic energy is captured and directed to the energy storage system. The remaining 

kinetic energy is dissipated through conventional wheel brakes or in a driveline or transmission 

retarder. Regenerative braking in a hybrid electric vehicle can require integration with the 

vehicle’s foundation (friction) braking system to maximize performance and safety. 

Today’s systems function by simultaneously using the regenerative features and the 

friction braking system, allowing only some of the kinetic energy to be saved for later use. 

Optimizing the integration of the regenerative braking system with the foundation brakes would

increase the benefits and is a focus for continued work. This type of hybrid regenerative braking 

system improves fuel economy, GHG emissions, brake heat, and wear.
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In a hydraulic hybrid system, deceleration energy is taken from the drivetrain by an inline 

hydraulic pump/motor unit by pumping hydraulic fluid into high pressure cylinders. The fluid, 

while not compressible, pushes against a membrane in the cylinder that compresses an inert gas 

to 5,000 PSI or more when fully charged. Upon acceleration, the energy stored in the 

pressurized tank pushes hydraulic fluid back into the drivetrain pump/motor unit, allowing it to 

motor into the drivetrain and assist the vehicle’s engine with the acceleration event. This heavyduty vehicle hybrid approach has been demonstrated successfully, producing good results on a 

number of commercial and military trucks.

Despite the significant future potential for hybrids discussed above, there are no simple 

solutions applicable for each heavy-duty hybrid application due to the large vocational vehicle 

fleet variation. A choice must be made relative to the requirements and priorities for the 

application. Challenges in motor subsystems such as gear reductions and cooling systems must 

be considered when comparing the specific power, power density, and cost of the motor 

assemblies. High speed motors can significantly reduce weight and size, but they require speed 

reduction gear sets that can offset some of the weight savings, reduce reliability and add cost and 

complexity. Air-cooled motors are simpler and generally less expensive than liquid cooled 

motors, but they are larger and heavier, and they require access to ambient air, which can carry

dirt, water, and other contaminants. Liquid-cooled motors are generally smaller and lighter for a 

given power rating, but they may require more complex cooling systems that can be avoided 

with air-cooled versions. Various coolant options, including water, water-glycol, and oil, are 

available for liquid-cooled motors but must be further researched for long term durability. 

Electric motors, power electronics, electrical safety, regenerative braking, and power-plant 

control optimization have been identified as the most critical technologies requiring further 

research to enable the development of higher efficiency hybrid electric propulsion systems.

2.4.5 Axles

2.4.5.1 Axle Efficiency

Axle efficiency is improved by reducing generally two categories of losses; mechanical 

losses and spin losses. 

Mechanical losses can be reduced by reducing the friction between the two gears in 

contact. This friction is reduced mainly by improving the surface finish of the gears. The other 

way of doing is by reducing the amount of distance the gear faces are sliding against each other. 

Generally speaking frictional losses are proportional to the torque on the axle not a function of 

rotational speed of the axle.

Spin losses on the other hand are a function of speed and not torque. One of the main 

ways to reduce the spin losses of the axle is by using a lower viscosity lubricant. Some highperformance lower viscosity formulations have been designed to have superior performance at 

high operating temperatures, and may have extended change intervals. 

A study conducted by researchers at Shell Global Solutions on a Mercedes Benz OM 

460LA heavy-duty diesel engine run under the World Harmonized Transient Cycle (WHTC) and 

World Harmonized Stationary Cycle (WHSC), used a combination of a SAE 5W-30 engine oil, 
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SAE 75W-80 gearbox oil and SAE 75W-90 axle oil. The combination yielded average fuel 

economy improvements of 1.8 percent over the WHTC and 1.1 percent over the WHSC, relative 

to a SAE 15W-40 engine oil, SAE 80W gearbox and SAE 90 axle oil [VT-27]. The baseline 

lubricants represent current mainstream products, and the new lubricants were top-tier 

formulations focusing on modified viscometric effects. Using the WHSC cycle, significant 

variations in the individual lubricant contribution under different speed and load conditions 

within the cycle were identified. Additionally, an average fuel economy improvement of 1.8 

percent was observed using medium-duty trucks under a range of typical European driving 

conditions in a controlled field trial.

66

Spin losses can also be reduced by lower the volume of lubricant in the sump. This 

reduces the surface area of the gears that is churning through the lubricant. One of the main 

challenges of doing this is making sure that there is still adequate coverage of lubricant on the 

gears and bearings as well as adequate circulation so that the lubricant temperature doesn’t rise 

too high and accelerate the aging of the lubricant. 

If a manufacturer wishes to demonstrate a benefit specific to any technology that 

improves axle efficiency, an axle efficiency test could be performed to support an off-cycle 

technology credit application. See draft RIA Chapter 3 for a description of the proposed test 

procedure for rear axle efficiency.

2.4.5.2 Gear Ratio

Combining with transmission ratio, selection of the axle ratio can play a significant role 

in vehicle performance. For an on-highway tractor, the axle ratio must be selected in such a way

that the engine can constantly run inside the sweet spot, where the engine efficiency is optimal 

for a typical constant cruise speed like 65 mile per mile. Although many vehicles on the road 

already use the fast axle ratio as low as 2.64:1 with the direct drive of transmission, which moves 

the engine speed in the range of 1200 rpm or even lower, most vehicles still use higher or slower 

axle ratio, which puts the engine speed in the range of 1300-1400 rpm. In order to take 

advantage of optimal engine speed, which is typically in the range of 1100-1150 rpm for HHD 

diesel vehicles, it is expected that the faster axle ratio lower than 2.64:1 would be widely used in 

2018 and beyond for tractors. Furthermore, in order to enhance vehicle performance, many axle 

manufacturers are developing dual speed axles, allowing vehicles to switch to the higher axle 

ratio during transient driving conditions, such as city traffic. On the vocational side, the ability

to start a heavy vehicle, climb hills, and operate smoothly at low speed is strongly influenced by 

axle ratio, and therefore, one can see a large of variation of axle ratios depending on the 

application. 

2.4.5.3 Tandem Drive Axle Improvements

Manufacturers are developing technologies to enable heavy trucks with two rear drive 

axles to be driven solely by the lead rear axle either permanently or on a part time basis.
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2.4.5.3.1 6 x 2

Most tractors and heavy heavy-duty vocational vehicles today have three axles – a steer 

axle and two rear drive axles, which is commonly referred to as a 6x4 configuration. 

Manufacturers offer 6x2 tractors that include one rear drive axle and one rear non-driving axle. 

The 6x2 tractors offer three distinct benefits. First, the non-driving rear axle does not have 

internal friction and therefore reduces the overall parasitic losses in the drivetrain. In addition, 

the 6x2 configuration typically weighs approximately 300 to 400 pounds less than a 6x4 

configuration.67 Finally, the 6x2 typically costs less or is cost neutral when compared to a 6x4 

tractor. Sources cite the effectiveness of 6x2 axles at between 1 and 3 percent.68 Similarly, with 

the increased use of double and triple trailers, which reduce the weight on the tractor axles when 

compared to a single trailer, manufacturers offer 4x2 axle configurations. The 4x2 axle 

configuration would have as good as or better fuel efficiency performance than a 6x2.

2.4.5.3.2 Enhanced 6x2 

One of the drawbacks of 6x2 axle is lack of traction, specifically during the winter 

condition and high grade road when the road is slippery. In order to overcome this deficiency, 

some axle manufacturers offer products that perform similar to the 6x4 configurations. 

SMARTandem offered by Meritor is just one of the examples.69 In this system, the axle runs 

6x2 for most time. Once the conditions that require more traction are experienced, the vehicle 

activates the system to add more loads into one the powered axle, thus instantly increasing 

traction. This system offers weight savings in the range of 300 to 400 lbs, as well as 2 percent 

fuel saving as compared with conventional 6x4 axle.

2.4.5.3.3 2.4.4.3.3 Disconnect 6x4 Axle

Based on confidential stakeholder discussions, the agencies anticipate that the axle 

market may offer, in the proposed time frame of Phase 2, a Class 8 version of the type of axle 

disconnect that today allows 4x4 operators of HD pickup trucks to automatically disconnect or 

reconnect the front axle depending on needs for traction in varying driving conditions. The Class 

8 version would likely function for the two tandem drive axles in a similar manner as the HD 

pickup trucks do for the front axle. The switching could be automated or user-commanded. In 

these cases, the axle actuator housing, sometimes called the axle disconnect housing, is part of 

the differential that houses the gears and shift fork required to lock two axles together. The axle 

actuator works together with the transfer case to send torque to all four wheel-ends. Recently, 

Dana Holding Corporation has developed an axle system that switches between the two modes 

based on driving conditions to maximize driveline efficiency.

70 When high traction is required, 

the system operates in 6x4 mode. When 6x4 tractive effort is not required, the system operates 

in 6x2 mode. It is reported that this type of system can offer 2.5 percent benefits.

In the 4x4 example, the transfer case connects the input from the transmission to the rear 

and front driveshafts. The axle actuator housing is found on the differential. In the 4x4 

example, a shift fork inside the axle actuator housing slides a locking collar over two gears 

locking both driver and passenger side axles together. In some 4x4 vehicles, those with 

automatic 4WD, this process occurs automatically. In others, with selective 4WD, the driver can 

choose to engage 4WD or RWD with a switch. These have slightly different axle actuator 
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housings and have actuator solenoids mounted to them.71 These systems would not provide the 

weight reduction benefit of the permanent 6x2 configuration, and may offer less fuel savings, 

especially with operator-switchable systems. 

2.4.6 Weight Reduction

Mass reduction is a technology that can be used in a manufacturer’s strategy to meet the 

proposed Phase 2 standards. Vehicle mass reduction (also referred to as “down-weighting” or 

‘light-weighting”), decreases fuel consumption and GHG emissions by reducing the energy

demand needed to overcome inertia forces, and rolling resistance. Reduced mass in heavy-duty 

vehicles can benefit fuel efficiency and CO2 emissions in two ways. If a truck is running at its 

gross vehicle weight limit with high density freight, more freight can be carried on each trip, 

increasing the truck’s ton-miles per gallon. If the vehicle is carrying lower density freight and is 

below the GVWR (or GCW) limit, the total vehicle mass is decreased, reducing rolling 

resistance and the power required to accelerate or climb grades.

Many vehicle components are typically made of heavier material, such as steel. 

Manufacturers have worked with mass reduction technologies for many years and a lot of these 

technologies have been used in production vehicles. The weight savings achieved by adopting 

mass reduction technologies offset weight gains due to increased vehicle size, larger powertrains, 

and increased feature content (sound insulation, entertainment systems, improved climate 

control, etc.). Generally, an empty truck makes up about one-third of the total vehicle weight. 

Every 10 percent drop in vehicle weight reduces fuel use about 5 percent.72 

Although many gains have been made to reduce vehicle mass, many of the features being 

added to modern tractors to benefit fuel efficiency, such as additional aerodynamic features or 

idle reduction systems, have the effect of increasing vehicle weight, causing mass to stay

relatively constant. Material and manufacturing technologies can also play a significant role in 

vehicle safety by reducing vehicle weight, and in the improved performance of vehicle passive 

and active safety systems. Hybrid powertrains, fuel cells and auxiliary power would not only 

present complex packaging and weight issues, they would further increase the need for 

reductions in the weight of the body, chassis, and powertrain components in order to maintain 

vehicle functionality. 

Manufacturers may employ a systematic approach to mass reduction, where the net mass 

reduction is the addition of a direct component or system mass reduction, also referred to as 

primary mass reduction, plus the additional mass reduction taken from indirect ancillary systems 

and components, also referred to as secondary mass reduction or mass compounding. 

Mass reduction can be achieved through a number of approaches, even while maintaining 

other vehicle functionalities. As summarized by NAS in its 2011 light duty vehicle report, there 

are two key strategies for primary mass reduction: 1) substituting lighter materials for heavier 

materials; and 2) changing the design to use less material.

73
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2.4.6.1 Material Substitution

Substitution of a material used in an assembly or a component for one with lower density 

and/or higher strength includes replacing a common material such as mild steel with higherstrength and advanced steels, aluminum, magnesium, and composite materials. In practice, 

material substitution tends to be quite specific to the manufacturer and situation. Some materials 

work better than others for particular vehicle components, and unless strength is matched, some 

substituted components may need to be more numerous (i.e. two brackets instead of one). 

Further, one choices of material may lead a manufacturer to invest more heavily in adjusting its 

manufacturing process to its properties, thus possibly impeding its ability to consider other

materials. The agencies recognize that like any type of mass reduction, material substitution has 

to be conducted not only with consideration to maintaining equivalent component strength, but 

also to maintaining all the other attributes of that component, system or vehicle, such as 

crashworthiness, durability, and noise, vibration and harshness (NVH).

One example that combines material substitution with component-elimination is the use

of wide-based single tires and aluminum rims to replace traditional dual tires and rims, 

eliminating eight steel rims and eight tires from a tractor. Using aluminum, metal alloys, metal 

matrix composites, and other lightweight components where appropriate can reduce empty 

vehicle weight (known as “tare weight”), improve fuel efficiency, and reduce greenhouse gas 

emissions. In addition, in weight-sensitive applications, lightweight components can allow more 

cargo and increased productivity. A report by the National Commission on Energy Policy

estimates that a fuel economy gain of 5.0 percent on certain applications could be achieved by

vehicle mass reduction further illustrating the fuel economy gains possible on heavy-duty 

applications.74 A report for the U.S. DOT estimated potential reductions in modal GHG 

emissions are 4.6 percent, though it also found that current light-weight materials are costly and 

are application- and vehicle-specific with need for further research and development for 

advanced materials.75

The principal barriers to overcome in reducing the weight of heavy vehicles are 

associated with the cost of lightweight materials, the difficulties in forming and manufacturing 

lightweight materials and structures, the cost of tooling for use in the manufacture of relatively

low-volume vehicles (when compared to automotive production volumes), and ultimately, the 

extreme durability requirements of heavy vehicles. While light-duty vehicles may have a life 

span requirement of several hundred thousand miles, typical heavy-duty commercial vehicles 

must last over 1 million miles with minimum maintenance, and often are used in secondary

applications for many more years. This requires high strength, lightweight materials that provide 

resistance to fatigue, corrosion, and can be economically repaired. Additionally, because of the 

limited production volumes and the high levels of customization in the heavy-duty market, 

tooling and manufacturing technologies that are used by the light-duty automotive industry are 

often uneconomical for heavy vehicle manufacturers. Lightweight materials such as aluminum, 

titanium and carbon fiber composites provide the opportunity for significant weight reductions, 

but their material cost and difficult forming and manufacturing requirements make it difficult for 

them to compete with low-cost steels. In addition, although mass reduction is currently 

occurring on both vocational vehicles and line haul tractors, the addition of other systems for fuel 

economy, performance or comfort increases the vehicle mass offsetting the mass reduction that 

has already occurred, thus is not captured in the overall vehicle mass measurement (e.g. 500 lbs 
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for WHR). Most vehicle manufacturers offer lightweight tractor models that are 1,000 or more 

pounds lighter than comparable models. Lighter-weight models combine different weight-saving 

options that may include:76

 Cast aluminum alloy wheels can save up to 40 pounds each for total savings of 400 

pounds

 Aluminum axle hubs can save over 120 pounds compared to ductile iron or steel

 Centrifuge brake drums can save nearly 100 pounds compared to standard brake drums

 Aluminum clutch housing can save 50 pounds compared to iron clutch housing

 Composite front axle leaf springs can save 70 pounds compared to steel springs

 Aluminum cab frames can save hundreds of pounds compared to standard steel frames

2.4.6.2 Synergistic Effects - Reduced Power Demand

Manufacturers employ a systematic approach to mass reduction, where the net mass 

reduction is the addition of a direct component or system mass reduction plus the additional mass 

reduction that can be taken from indirect ancillary systems and components, as a result of full 

vehicle optimization, effectively compounding or obtaining a secondary mass reduction from a 

primary mass reduction. The strategy of using less material compared to the baseline component 

or system can be achieved by optimizing the design and structure of vehicle components, 

systems and vehicle structure. Vehicle manufacturers have long used these continuallyimproving CAE tools to optimize vehicle designs. For example, the Future Steel Vehicle (FSV) 

project sponsored by WorldAutoSteel used three levels of optimization: topology optimization, 

low fidelity 3G (Geometry Grade and Gauge) optimization, and subsystem optimization, to 

achieve 30 percent mass reduction in the body structure of a vehicle with a mild steel unibody

structure.77 Using less material can also be achieved through improving the manufacturing 

process, such as by using improved joining technologies and parts consolidation. This method is 

often used in combination with applying new materials.

If vehicle mass is reduced sufficiently through application of the two primary strategies 

of using less material and material substitution described above, secondary mass reduction 

options may become available. Secondary mass reduction is enabled when the load requirements 

of a component are reduced as a result of primary mass reduction. If the primary mass reduction 

reaches a sufficient level, a manufacturer may use a smaller, lighter, and potentially more 

efficient powertrain while maintaining vehicle performance. If a powertrain is downsized, a 

portion of the mass reduction may be attributed to the reduced torque requirement that results 

from the lower vehicle mass. The lower torque requirement enables a reduction in engine 

displacement, changes to transmission torque converter and gear ratios, and changes to final 

drive gear ratio. The reduced powertrain torque may enable the downsizing and/or mass 

reduction of powertrain components and accompanying reduced rotating mass (e.g., for 

transmission, driveshafts/halfshafts, wheels, and tires) without sacrificing powertrain durability. 

However, there may trade-offs, as it is possible that use of a downsized engine may require a 

transmission with more gears. The combined mass reductions of the engine, drivetrain, and body 

would reduce stresses on the suspension components, steering components, wheels, tires, and 

brakes, which can allow further reductions in the mass of these subsystems. Reducing the 
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unsprung masses such as the brakes, control arms, wheels, and tires further reduce stresses in the 

suspension mounting points, which would allow for further optimization and potential mass 

reduction.

One example of a synergistic effect is rotational inertia. Reducing the weight of rotating 

components provides an enhanced fuel efficiency benefit over reducing the weight of static 

components. In theory, as components such as brake rotors, brake drums, wheels, tires, 

crankshafts, camshafts, and piston assemblies become lighter, the power consumption to rotate 

the masses would be directly proportional to the mass decrease. Using physical properties of a 

rotating component such as a wheel, it is relatively straightforward to calculate an equivalent 

mass. However, we do not have enough information to derive industry average values for 

equivalent mass, nor have we evaluated the best way for GEM to account for this. Using typical 

values for a heavy-duty steel wheel compared to a similar-sized aluminum wheel, the agencies 

estimate the equivalent mass ratio is in the range of 1.2 to 1.3. That means that by reducing the 

mass of a wheel by 20 pounds, the vehicle could theoretically perform as if 26 pounds had been 

reduced.

Estimates of the synergistic effects of mass reduction and the compounding effect that 

occurs along with it can vary significantly from one report to another. For example, in 

discussing its estimate, an Auto-Steel Partnership report states that “These secondary mass 

changes can be considerable—estimated at an additional 0.7 to 1.8 times the initial mass 

change.”78 This means for each one pound reduction in a primary component, up to 1.8 pounds 

can be reduced from other structures in the vehicle (i.e., a 180 percent factor). The report also 

discusses that a primary variable in the realized secondary weight reduction is whether or not the 

powertrain components can be included in the mass reduction effort, with the lower end 

estimates being applicable when powertrain elements are unavailable for mass reduction. 

However, another report by the Aluminum Association, which primarily focuses on the use of 

aluminum as an alternative material for steel, estimated a factor of 64 percent for secondary mass 

reduction even though some powertrain elements were considered in the analysis.79 That report 

also notes that typical values for this factor vary from 50 to 100 percent. Although there is a 

wide variation in stated estimates, synergistic mass reductions do exist, and the effects result in 

tangible mass reductions. Mass reductions in a single vehicle component, for example a door 

side impact/intrusion system, may actually result in a significantly higher weight savings in the 

total vehicle, depending on how well the manufacturer integrates the modification into the 

overall vehicle design. Accordingly, care must be taken when reviewing reports on weight 

reduction methods and practices to ascertain if compounding effects have been considered or not.

2.4.7 Vehicle Speed Limiter

The power required to move a vehicle increases as the vehicle speed increases. 

Travelling at lower speeds provides additional efficiency to the vehicle performance. Most 

vehicles today have the ability to electronically control the maximum vehicle speed through the 

engine controller. This feature is used today by fleets and owners to provide increased safety 

and fuel economy. Currently, these features are designed to be able to be changed by the owner 

and/or dealer.
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The impact of this feature is dependent on the difference between the governed speed and 

the speed that would have been travelled, which is dependent on road type, state speed limits, 

traffic congestion, and other factors. The agencies plan to assess the benefit of a vehicle speed 

limiter by reducing the maximum drive cycle speed on the 65 mph Cruise mode of the cycle. 

The maximum speed of the drive cycle is 65 mph, therefore any vehicle speed limit with a 

setting greater than this would show no benefit for purposes of these regulations, but may still 

show benefit in the real world in states where the interstate truck speed limit is greater than the 

national average of 65.5 mph.

The benefits of this simple technology are widely recognized. The American Trucking 

Association (ATA) developed six recommendations to reduce carbon emissions from trucks in 

the United States. Their first recommendation is to enact a national truck speed limit of 65 mph 

and require that trucks manufactured after 1992 have speed governors set at not greater than 65 

mph.80 The SmartWay program includes speed management as one of their key Clean Freight 

Strategies and provides information to the public regarding the benefit of lower highway

speeds.81

Some countries have enacted regulations to reduce truck speeds. For example, the United 

Kingdom introduced regulations in 2005 which require new trucks used for goods movement to 

have a vehicle speed limiter not to exceed 90 km/hr (56 mph).82 The Canadian Provinces of 

Ontario and Quebec developed regulations which took effect in January 2009 that requires onhighway commercial heavy-duty trucks to have speed limiters which limit the truck’s speed to 

105 km/hr (65 mph).83

Many truck fleets consider speed limiter application a good business practice in their 

operations. A Canadian assessment of heavy-duty truck speed limiters estimated that 60 percent 

of heavy truck fleets in North America use speed limiters.83 Con Way Freight, Con Way

Truckload, and Wal-Mart currently govern the speeds of their fleets between 62 and 65 mph.84

A potential disbenefit of this technology is the additional time required for goods 

movement, or loss of productivity. The elasticity between speed reduction and productivity loss 

has not been well defined in industry. The Canadian assessment of speed limiters cited above 

found that the fuel savings due to the lower operating speeds outweigh any productivity losses. 

A general consensus among the OEMs is that a one percent decrease in speed might lower 

productivity by approximately 0.2 percent.84

2.4.8 Reduced Idling Time

2.4.8.1 Engine Shutdown with Alternate Power Source during Hoteling

Class 8 heavy-duty diesel truck extended engine idling expends significant amounts of 

fuel in the United States. Department of Transportation regulations require a certain amount of 

rest for a corresponding period of driving hours, as discussed in Chapter 1. Extended idle occurs 

when Class 8 long haul drivers rest in the sleeper/cab compartment during rest periods as drivers 

find it more convenient and economical to rest in the truck cab itself. In many cases it is the only

option available. During this rest period a driver will generally idle the truck in order to provide 

heating or cooling or run on-board appliances. During rest periods the truck’s main propulsion 
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engine is running but not engaged in gear and it remains in a stationary position. In some cases 

the engine can idle in excess of 10 hours. During this period of time, fuel consumption will 

generally average 0.8 gallons per hour.113 Average overnight fuel usage would exceed 8 gallons 

in this example. When multiplied by the number of long haul trucks without idle control 

technology that operate on national highways on a daily basis, the number of gallons consumed 

by extended idling would exceed 3 million gallons per day. Fortunately, a number of 

alternatives (idling reduction technologies) are available to alleviate this situation.

2.4.8.1.1 Idle Control Technologies

Idle reduction technologies in general utilize an alternative energy source in place of 

operating the main engine. By using these devices the truck driver can obtain needed power for 

services and appliances without running the engine. A number of these devices attach to the 

truck providing heat, air conditioning, or electrical power for microwave ovens, televisions, etc.

The idle control technologies (along with their typical hourly fuel rate) available today

include the following:85

 Auxiliary Power Unit (APU) powers the truck’s heating, cooling, and electrical system. 

The fuel use of an APU is typically 0.2 gallons per hour

 Fuel Operated Heater (FOH) provides heating services to the truck through small diesel 

fired heaters. The fuel use is typically 0.04 gallons per hour

 Battery Air Conditioning Systems (BAC) provides cooling to the truck

 Thermal Storage Systems provide cooling to trucks

Another alternative involves electrified parking spaces, with or without modification to 

the truck. An electrified parking space system operates independently of the truck’s engine and 

allows the truck engine to be turned off while it supplies heating, cooling, and electrical power. 

These systems provide off-board electrical power to operate either:

1. A single system electrification which requires no on-board equipment by providing an 

independent heating, cooling, and electrical power system, or

2. A dual system which allows driver to plug in on-board equipment

In the first case, power is provided to stationary equipment that is temporarily attached to 

the truck. In the second, the truck is modified to accept power from the electrical grid to operate 

on-board truck equipment. The retail price of idle reduction systems varies depending on the 

level of sophistication. For example, on-board technologies such as APUs can retail for over 

$7,000 while options such as electrified parking spaces require negligible up-front costs for 

equipment for the tractor itself, but will accrue fees with usage.86

CO2 emissions and fuel consumption during extended idling are significant contributors 

to emissions and fuel consumption from Class 8 sleeper cabs. The federal test procedure does 

evaluate idle emissions and fuel consumption as part of the drive cycle and related emissions 

measurement. However, long duration extended idle emissions and fuel consumption are not 

fully represented during the prescribed test cycle. To address the fact that real-world fuel and 
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emissions savings can occur with idle reduction technologies that cannot be reflected on the test 

cycle, the agencies adopted in Phase 1 a credit mechanism for manufacturers who provide for 

idle control using an automatic engine shutdown (AES) system on the tractor. This credit 

recognizes the CO2 reductions and fuel consumption savings attributed to idle control systems 

and allows vehicle manufacturers flexibility in product design and performance capabilities, 

compared to an alternative where the agencies would allow credits for specific idle control 

technologies.

2.4.8.2 Stop Start

For heavy-duty vehicles to apply engine stop-start technology without a reduction in 

vehicle function, some additional vehicle technologies are needed. To some extent this could be 

considered similar to a mild hybrid system, but it is not the same as the mild hybrid system 

described for HD pickups and vans described below in Chapter 2.5. The agencies are projecting 

the presence of a battery sufficient to offer electrified power steering, and some other electrified 

accessories. Some systems may replace the conventional alternator with a belt or crank driven 

starter/alternator and may add high voltage electrical accessories (which may include electric 

power steering and an auxiliary automatic transmission pump). The limited electrical 

requirements of these systems allow the use of lead-acid batteries or supercapacitors for energy

storage, or the use of a small lithium-ion battery pack.

The NACFE Idle Reduction Confidence report was written with long haul tractors in 

mind; however the section on vehicle electrification discusses inverters and on-vehicle solar 

energy capture, and offers some insights relevant to vocational vehicle electrification as it 

pertains to stop-start systems.87 Inverters and beltless alternators can use DC power stored in 

batteries to power on-board electrical devices and re-start engines. One example of a company 

that supplies battery-inverter idle reduction systems for vocational vehicles is Vanner.88 There 

are also systems available today that are designed to capture solar energy and store this energy

for distribution to electrified accessories and engine re-starting. One example of a company that 

supplies on-vehicle solar energy capture for vocational vehicles is eNow.

89

2.4.8.3 Neutral Idle

Automatic transmissions historically apply torque to an engine when in gear at zero 

speed, such as when stopped at a traffic light. These transmissions can be programmed to place 

a smaller load on the engine, resulting in lower rpm and lower fuel consumption, essentially

shifting the transmission to neutral at zero speed.

2.4.9 Air Conditioning

2.4.9.1 Refrigerant Leakage

Hydrofluorocarbon (HFC) refrigerants, which are powerful GHG pollutants, can be 

emitted to the atmosphere through component and system leaks during operation, during 

maintenance and servicing, and with disposal at the end of the vehicle’s life. The current widelyused refrigerant – R134a, has a much higher global warming potential (GWP) than CO2, 
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therefore a small leakage of this refrigerant has a much greater global warming impact than a 

similar amount of emissions of CO2 or other mobile source GHGs. 

Direct emissions of HFC from air conditioning systems can be reduced by minimizing 

system leaks. Based on measurements from 300 European light-duty vehicles (collected in 2002 

and 2003), Schwarz and Harnisch estimate that the average HFC direct leakage rate from modern 

A/C systems was estimated to be 53 g/yr.90 This corresponds to a leakage rate of 6.9 percent per 

year. This was estimated by extracting the refrigerant from recruited vehicles and comparing the 

amount extracted to the amount originally filled (as per the vehicle specifications). The fleet and 

size of vehicles differs from Europe and the United States, therefore it is conceivable that 

vehicles in the United States could have a different leakage rate. The authors measured the 

average charge of refrigerant at initial fill to be about 747 grams (it is somewhat higher in the 

U.S. at 770g), and that the smaller cars (684 gram charge) emitted less than the higher charge 

vehicles (883 gram charge). Moreover, due to the climate differences, the A/C usage patterns 

also vary between the two continents, which may influence leakage rates.

Vincent et al., from the California Air Resources Board estimated the in-use refrigerant 

leakage rate to be 80 g/yr.

91

 This is based on consumption of refrigerant in commercial fleets, 

surveys of vehicle owners and technicians. The study assumed an average A/C charge size of 

950 grams and a recharge rate of 1 in 16 years (lifetime). The recharges occurred when the 

system was 52 percent empty and the fraction recovered at end-of-life was 8.5 percent.

Manufacturers today are complying with the HD Phase 1 program requirements to reduce 

A/C leakage emissions by utilizing high-quality, low-leakage air conditioning system 

components in the production of new tractors, and HD pickup trucks and vans. Some of the 

components available to manufacturers are low-permeation flexible hoses, multiple o-ring or seal 

washer connections, and multiple-lip compressor shaft seals. The availability of low leakage 

components in the market is being driven by the air conditioning credit program in the light-duty 

GHG rulemaking. The cooperative industry and government Improved Mobile Air Conditioning 

(IMAC) program has demonstrated that new-vehicle leakage emissions can be reduced by 50 

percent by reducing the number and improving the quality of the components, fittings, seals, and 

hoses of the A/C system.92

2.4.9.2 System Efficiency

A program could be developed that includes efficiency improvements. CO2- equivalent 

emissions and fuel consumption are also associated with air conditioner efficiency, since air 

conditioners create load on the engine. See 74 FR at 49529. However, as in Phase 1, the 

agencies are not proposing air conditioning efficiency standards for heavy-duty vehicles, as the 

fuel consumption and CO2 emissions due to air conditioning systems in heavy-duty trucks are 

minimal (compared to their overall fuel consumption and emissions of CO2). For example, EPA 

conducted modeling of a Class 8 sleeper cab using GEM to evaluate the impact of air 

conditioning and found that it leads to approximately 1 gram of CO2/ton- mile. Therefore, a 

projected 24 percent improvement of the air conditioning system (the level projected in the lightduty GHG rulemaking), would only reduce CO2 emissions by less than 0.3 g CO2/ton-mile, or 

approximately 0.3 percent of the baseline Class 8 sleeper cab CO2 emissions.
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2.4.9.3 Solar Control

Solar reflective paint and solar control glazing can reduce the temperature inside a 

vehicle, and therefore reduce the air conditioning requirements. The reduction in air 

conditioning load can lead to reductions in fuel consumption and GHG emissions. CARB’s Low 

Emission Vehicle III Regulations (LEVIII) include a GHG credit for this technology.

93

 Solar 

reflective paints reflect approximately a half of the solar energy by reflecting the infrared portion 

of the solar spectrum. A study conducted by National Renewable Energy Laboratory found

benefits to sleeper cab tractors using reflective paint.94 Solar control glazing reflects some of the 

solar energy from the glass. CARB found that most heavy-duty trucks today use solar absorbing 

glass.

There are many factors that influence the level of emissions and fuel consumption 

reductions due to solar control glazing and solar reflective paint. The fraction of time spent 

idling during the daytime hours, the fraction of hours of the day that are sunny, the ambient 

temperatures, the wind conditions and/or vehicle speed, the fraction of the vehicles that are 

painted colors other than white, and other factors influence the potential impact of these 

technologies. Because of the difficulty in assessing the potential emission reductions from solar 

control paint and glazing, the agencies are not proposing this technology as part of HD Phase 2, 

but these types of technologies could be considered under the innovative technology program.

2.4.10 Other Accessory Improvements

Electric power steering (EPS) provides a potential reduction in CO2 emissions and fuel 

consumption over hydraulic power steering because of reduced overall accessory loads. This 

eliminates the parasitic losses associated with belt-driven power steering pumps which 

consistently draw load from the engine to pump hydraulic fluid through the steering actuation 

systems even when the wheels are not being turned. EPS is an enabler for all vehicle 

hybridization technologies since it provides power steering when the engine is off. EPS may be 

implemented on most vehicles with a standard 12V system. Some heavier vehicles such as Class 

2b and 3 may require a higher voltage system which may add cost and complexity.

The 2017 light-duty final rule estimated a one to two percent effectiveness based on the 

2002 NAS report, a Sierra Research report, and confidential manufacturer data. The SwRI report 

estimated 0.8 percent to 1 percent effectiveness. The agencies reviewed these SwRI 

effectiveness estimates and found them to be accurate, thus they have been retained for this 

proposal.

In addition to the purely hybrid technologies, which decreases the proportion of 

propulsion energy coming from the fuel by increasing the proportion of that energy coming from 

electricity, there are other steps that can be taken to improve the efficiency of auxiliary functions 

(e.g., power-assisted steering or air-conditioning) which also reduce CO2 emissions and fuel 

consumption. Optimization of the auxiliary functions is collectively referred to as vehicle or 

accessory load electrification because they generally use electricity instead of engine power. 

These improvements are considered enablers for hybrid systems.
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2.4.11 Predictive Cruise Control

Cruise control is commonly used in light-duty and heavy-duty applications to maintain a 

vehicle at a set speed. However, cruise control systems with additional intelligence and 

predictive control in are much more complex but offer opportunities to reduce fuel consumption 

and GHG emissions. Many of the heavy-duty manufacturers are developing intelligent cruise 

control systems and though they resemble each other in overall function, each manufacturer is 

doing it differently.

As an example, an intelligent cruise control system partnered with a source of elevation 

information could detect when the vehicle is on a hill and know when it is close to cresting the 

hill. During this time, the vehicle may be allowed to temporarily travel at a lower speed to 

prevent the need for a transmission downshift, which consumes more fuel because it requires the 

engine to increase the rpm and run in a less efficient part of the fuel map. Similarly, predictive 

cruise control allows a vehicle to exceed the speed set point by a specified amount so that the 

vehicle will start the next hill at a higher speed and reduce the likelihood of needing to downshift 

on the next hill.

The amount of reduction in fuel consumption and CO2 emissions depends significantly 

on the terrain. Sources estimate that the overall savings is approximately two percent.95

2.5 Technology Application and Estimated Costs – HD Pickups and Vans

2.5.1 Gasoline Engines 

Spark ignited (gasoline) engines used in complete Class 2b and 3 pickups and vans

include engines offered in a manufacturer’s light-duty truck counterparts, as well as engines 

specific to the Class 2b and 3 segment. Based on 2014 MY specifications, these engines 

typically range in displacement between 5 and 7 liters, though smaller and larger engines have 

also been used in this market. The majority of these engines are a V8 configuration, although the 

V10 configuration is also marketed. 

The engine technologies are based on the technologies described in the Light-Duty

Vehicle Greenhouse Gas Emission Standards and Corporate Average Fuel Economy Standards 

Joint Technical Support Document and Sections 2.2 and 2.3 above.

96

 Some of the references 

come from the 2010 NAS Report, Technologies and Approaches to Reducing the Fuel 

Consumption of Medium and Heavy-Duty Vehicles. These technologies include engine friction 

reduction, cam phasing, cylinder deactivation and stoichiometric gas direct injection. Included 

with each technology description is an estimate of the improvement in fuel consumption and 

GHGs that is achievable through the use of the technology in heavy-duty pickup trucks and vans. 

2.5.1.1 Low Friction Lubricants

One of the most basic methods of reducing fuel consumption in both gasoline and diesel 

engines is the use of lower viscosity engine lubricants. More advanced multi-viscosity engine 

oils are available today with improved performance in a wider temperature band and with better 

lubricating properties. This can be accomplished by changes to the oil base stock (e.g., 
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switching engine lubricants from a Group I base oils to lower-friction, lower viscosity Group III 

synthetic) and through changes to lubricant additive packages (e.g., friction modifiers and 

viscosity improvers). The use of 5W-30 motor oil is now widespread and auto manufacturers are 

introducing the use of even lower viscosity oils, such as 5W-20 and 0W-20, to improve coldflow properties and reduce cold start friction. However, in some cases, changes to the 

crankshaft, rod and main bearings and changes to the mechanical tolerances of engine 

components may be required. In all cases, durability testing would be required to ensure that 

durability is not compromised. The shift to lower viscosity and lower friction lubricants would

also improve the effectiveness of valvetrain technologies such as cylinder deactivation, which 

rely on a minimum oil temperature (viscosity) for operation.

Based on light-duty 2017-2025 MY vehicle rulemaking, and previously-received 

confidential manufacturer data, the agencies have estimated the effectiveness of low friction

lubricants to be between 0 to 1 percent.

We present cost estimates for this technology in Chapter 2.12 of this draft RIA.

2.5.1.2 Engine Friction Reduction 

Manufacturers can reduce friction and improve fuel consumption by improving the 

design of engine components and subsystems. Approximately 10 percent of the energy

consumed by a vehicle is lost to friction, and just over half is due to frictional losses within the 

engine. Examples include improvements in low-tension piston rings, piston skirt design, roller 

cam followers, improved crankshaft design and bearings, material coatings, material substitution, 

more optimal thermal management, and piston and cylinder surface treatments. Additionally, as 

computer-aided modeling software continues to improve, more opportunities for evolutionary

friction reductions may become available.

Estimations of fuel consumption improvements due to reduced engine friction from the 

2015 NHTSA Technology Study range from 1 percent to 2 percent. The agencies believe that 

this range is accurate.

We present cost estimates for this technology in Chapter 2.12 of this draft RIA.

2.5.1.3 Engine Parasitic Demand Reduction

Manufacturers can reduce mechanical engine loads and improve fuel consumption by

implementing variable-displacement oil pumps, higher-efficiency direct injection fuel pumps, 

and variable speed/displacement coolant pumps.

Estimations of fuel consumption improvements due to reduced engine parasitic demand

from the 2015 NHTSA Technology Study range from 1 percent to 2 percent. The agencies 

believe that this range is accurate.

We present cost estimates for this technology in Chapter 2.12 of this draft RIA.
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2.5.1.4 Variable Valve Timing

Variable valve timing (VVT) classifies a family of valve-train designs that alter the 

timing of the intake valve, exhaust valve, or both, primarily to reduce pumping losses, increase 

specific power, and control the level of residual gases in the cylinder. VVT reduces pumping 

losses when the engine is lightly loaded by controlling valve timing closer to the optimum 

needed to sustain horsepower and torque. VVT can also improve volumetric efficiency at higher 

engine speeds and loads. Additionally, VVT can be used to alter (and optimize) the effective 

compression ratio where it is advantageous for certain engine operating modes (e.g., in the 

Atkinson Cycle).

VVT has now become a widely adopted technology in the light duty fleet: in MY 2014, 

most of all new cars and light trucks had engines with some method of variable valve timing.97

Manufacturers are currently using many different types of variable valve timing, which have a 

variety of different names and methods. Therefore, the degree of further improvement across the 

fleet is limited by the level of valvetrain technology already implemented on the vehicles. The 

three major types of VVT are listed below.

Each of the implementations of VVT uses a cam phaser to adjust the camshaft angular 

position relative to the crankshaft position, referred to as “camshaft phasing.” The phase 

adjustment results in changes to the pumping work required by the engine to accomplish the gas 

exchange process. The majority of current cam phaser applications use hydraulically-actuated 

units, powered by engine oil pressure and managed by a solenoid that controls the oil pressure 

supplied to the phaser.

2.5.1.4.1 Coupled Cam Phasing for Overhead Valve (OHV) and Single 

Overhead Camshaft (SOHC) Engines

Valvetrains with coupled (or coordinated) cam phasing (CCP) can modify the timing of 

both the inlet valves and the exhaust valves an equal amount by varying the phasing of the 

camshaft across an engine’s range of operating speeds; also known as VVT. For engines 

configured as an overhead valve (OHV) or as a single overhead camshaft (SOHC) only one cam 

phaser is required per camshaft to achieve CCP. 

Based on the heavy-duty 2014-2018 MY vehicle rulemaking, 2015 NHTSA Technology

Study, and previously-received confidential manufacturer data, the agencies estimate the fuel 

consumption reduction effectiveness of this technology to be between 1 and 3 percent.

We present cost estimates for this technology in Chapter 2.12 of this draft RIA. 

2.5.1.4.2 Intake Cam Phasing (ICP) for Dual Overhead Camshaft Engines 

(DOHC)

Valvetrains with ICP, which is the simplest of the cam phasing technologies, can modify

the timing of the inlet valves by phasing the intake camshaft while the exhaust valve timing 

remains fixed. This requires the addition of a cam phaser on each bank of intake valves on the 
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engine. An in-line 4-cylinder engine has one bank of intake valves, while V-configured engines 

have two banks of intake valves.

Some newer Class 2b and 3 market entries are offering dual overhead camshaft (DOHC) 

engine designs where two camshafts are used to operate the intake and exhaust valves 

independently. Consistent with the heavy-duty 2014-2018 MY vehicle rulemaking and the SwRI 

report, the agencies agree with the effectiveness values of 1 to 2 percent reduction in fuel 

consumption for this technology.

2.5.1.4.3 Dual Cam Phasing (DCP) for Dual Overhead Camshaft Engines 

(DOHC)

The most flexible VVT design is dual (independent) cam phasing, where the intake and 

exhaust valve opening and closing events are controlled independently. This option allows the 

option of controlling valve overlap, which can be used as an internal EGR strategy. At low 

engine loads, DCP creates a reduction in pumping losses, resulting in improved fuel 

consumption. Increased internal EGR also results in lower engine-out NOX emissions. The 

amount by which fuel consumption is improved depends on the residual tolerance of the 

combustion system. Additional improvements are observed at idle, where low valve overlap 

could result in improved combustion stability, potentially reducing idle fuel consumption. DCP 

requires two cam phasers on each bank of the engine. 

Some newer Class 2b and 3 market entries are offering dual overhead camshaft (DOHC) 

engine designs where two camshafts are used to operate the intake and exhaust valves 

independently. Consistent with the light-duty 2012-2016 MY vehicle rulemaking and the SwRI

report, the agencies agree with the effectiveness values of 1 to 3 percent reduction in fuel 

consumption for this technology.

We present cost estimates for this technology in Chapter 2.12 of this draft RIA.

2.5.1.5 Variable Valve Lift (VVL)

Controlling the lift of the valves provides a potential for further efficiency improvements. 

By optimizing the valve-lift profile for specific engine operating regions, the pumping losses can 

be reduced by reducing the amount of throttling required to produce the desired engine power 

output. By moving the throttling losses further downstream of the throttle valve, the heat 

transfer losses that occur from the throttling process are directed into the fresh charge-air mixture 

just prior to compression, delaying the onset of knock-limited combustion processes. Variable 

valve lift control can also be used to induce in-cylinder mixture motion, which improves fuel-air 

mixing and can result in improved thermodynamic efficiency. Variable valve lift control can 

also potentially reduce overall valvetrain friction. At the same time, such systems may also incur 

increased parasitic losses associated with their actuation mechanisms. A number of 

manufacturers have already implemented VVL into their fleets (Toyota, Honda, and BMW). 

There are two major classifications of variable valve lift, described below:
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2.5.1.5.1 Discrete Variable Valve Lift (DVVL)

Discrete variable valve lift (DVVL) systems allow the selection between two or three 

discrete cam profiles by means of a hydraulically-actuated mechanical system. By optimizing 

the cam profile for specific engine operating regions, the pumping losses can be reduced by

reducing the amount of throttling required to produce the desired engine power output. This 

increases the efficiency of the engine. These cam profiles consist of a low and a high-lift lobe, 

and may include an inert or blank lobe to incorporate cylinder deactivation (in the case of a 3-

step DVVL system). DVVL is normally applied together with VVT control. DVVL is also 

known as Cam Profile Switching (CPS). DVVL is a mature technology with low technical risk. 

Based on the light-duty MY 2017-2025 final rule, previously-received confidential 

manufacturer data, 2015 NHTSA Technology Study, and report from the Northeast States Center 

for a Clean Air Future (NESCCAF), the agencies estimate the fuel consumption reduction 

effectiveness of this technology to be between 1 and 3 percent.

We present cost estimates for this technology in Chapter 2.12 of this draft RIA.

2.5.1.6 Cylinder Deactivation 

In conventional spark-ignited engines throttling the airflow controls engine torque output. 

At partial loads, efficiency can be improved by using cylinder deactivation instead of throttling. 

Cylinder deactivation can improve engine efficiency by disabling or deactivating (usually) half 

of the cylinders when the load is less than half of the engine’s total torque capability – the valves 

are kept closed, and no fuel is injected – as a result, the trapped air within the deactivated 

cylinders is simply compressed and expanded as an air spring, with reduced friction and heat 

losses. The active cylinders combust at almost double the load required if all of the cylinders 

were operating. Pumping losses are significantly reduced as long as the engine is operated in 

this “part-cylinder” mode.

Cylinder deactivation control strategy relies on setting maximum manifold absolute 

pressures or predicted torque within which it can deactivate the cylinders. Noise and vibration 

issues reduce the operating range to which cylinder deactivation is allowed, although 

manufacturers are exploring vehicle changes that enable increasing the amount of time that 

cylinder deactivation might be suitable. Some manufacturers may choose to adopt active engine 

mounts and/or active noise cancellations systems to address Noise Vibration and Harshness 

(NVH) concerns and to allow a greater operating range of activation. 

Effectiveness improvements scale roughly with engine displacement-to-vehicle weight 

ratio: the higher displacement-to-weight vehicles, operating at lower relative loads for normal 

driving, have the potential to operate in part-cylinder mode more frequently. 

Based on the 2015 NHTSA Technology Study and previously-received confidential 

manufacturer data, the agencies estimate the fuel consumption reduction effectiveness of this 

technology to be between 2.5 and 3.5 percent.

We present cost estimates for this technology in Chapter 2.12 of this draft RIA.
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2.5.1.7 Stoichiometric Gasoline Direct Injection 

Stoichiometric gasoline direct injection (SGDI) engines inject fuel at high pressure 

directly into the combustion chamber (rather than the intake port in port fuel injection). SGDI

requires changes to the injector design, an additional high pressure fuel pump, new fuel rails to 

handle the higher fuel pressures, and changes to the cylinder head and piston crown design. 

Direct injection of the fuel into the cylinder improves cooling of the air/fuel charge within the 

cylinder, which allows for higher compression ratios and increased thermodynamic efficiency

without the onset of combustion knock. Recent injector design advances, improved electronic 

engine management systems and the introduction of multiple injection events per cylinder firing 

cycle promote better mixing of the air and fuel, enhance combustion rates, increase residual 

exhaust gas tolerance and improve cold start emissions. SGDI engines achieve higher power 

density and match well with other technologies, such as boosting and variable valvetrain designs.

Several manufacturers have recently introduced vehicles with SGDI engines, including 

GM and Ford, who have announced their plans to increase dramatically the number of SGDI 

engines in their light-duty portfolios.

Based on the heavy-duty 2014-2018 MY vehicle rulemaking, 2015 NHTSA Technology

Study, and previously-received confidential manufacturer data, the agencies estimate the fuel 

consumption reduction effectiveness of SGDI to be between 1 and 2 percent.

We present cost estimates for this technology in Chapter 2.12 of this draft RIA.

2.5.1.8 Turbocharging and Downsizing (TRBDS) 

The specific power of a naturally aspirated engine is primarily limited by the rate at 

which the engine is able to draw air into the combustion chambers. Turbocharging and 

supercharging (grouped together here as boosting) are two methods to increase the intake 

manifold pressure and cylinder charge-air mass above naturally aspirated levels. Boosting 

increases the airflow into the engine, thus increasing the specific power level, and with it the 

ability to reduce engine displacement while maintaining performance. This effectively reduces 

the pumping losses at lighter loads in comparison to a larger, naturally aspirated engine.

Almost every major manufacturer currently markets a vehicle with some form of 

boosting. While boosting has been a common practice for increasing performance for several 

decades, turbocharging has considerable potential to improve fuel economy and reduce CO2

emissions when the engine displacement is also reduced. Specific power levels for a boosted 

engine often exceed 100 hp/L, compared to average naturally aspirated engine power densities of 

roughly 70 hp/L. As a result, engines can be downsized roughly 30 percent or higher while 

maintaining similar peak output levels. In the last decade, improvements to turbocharger turbine 

and compressor design have improved their reliability and performance across the entire engine 

operating range. New variable geometry turbines and ball-bearing center cartridges allow faster 

turbocharger spool-up (virtually eliminating the once-common “turbo lag”) while maintaining 

high flow rates for increased boost at high engine speeds. Low speed torque output has been 

dramatically improved for modern turbocharged engines. However, even with turbocharger 

improvements, maximum engine torque at very low engine speed conditions, for example launch 
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from standstill, is increased less than at mid and high engine speed conditions. The potential to 

downsize engines may be less on vehicles with low displacement to vehicle mass ratios for 

example a very small displacement engine in a vehicle with significant curb weight, in order to 

provide adequate acceleration from standstill, particularly up grades or at high altitudes. 

Use of GDI systems with turbocharged engines and charge air cooling also reduces the 

fuel octane requirements for knock limited combustion and allows the use of higher compression 

ratios. Ford’s “EcoBoost” downsized, turbocharged GDI engines introduced on MY 2010 

vehicles allow the replacement of V8 engines with V6 engines with improved in 0-60 mph 

acceleration and with fuel economy improvements of up to 12 percent.98

Recently published data with advanced spray-guided injection systems and more 

aggressive engine downsizing targeted towards reduced fuel consumption and CO2 emissions 

reductions indicate that the potential for reducing CO2 emissions for turbocharged, downsized 

GDI engines may be as much as 15 to 30 percent relative to port-fuel-injected engines.14,15,16,17,18 

Confidential manufacturer data suggests an incremental range of fuel consumption and CO2

emission reduction of 4.8 to 7.5 percent for turbocharging and downsizing. Other publiclyavailable sources suggest a fuel consumption and CO2 emission reduction of 8 to 13 percent 

compared to current-production naturally-aspirated engines without friction reduction or other 

fuel economy technologies: a joint technical paper by Bosch and Ricardo suggesting fuel 

economy gain of 8 to 10 percent for downsizing from a 5.7 liter port injection V8 to a 3.6 liter 

V6 with direct injection using a wall-guided direct injection system;99 a Renault report 

suggesting a 11.9 percent NEDC fuel consumption gain for downsizing from a 1.4 liter port 

injection in-line 4-cylinder engine to a 1.0 liter in-line 4-cylinder engine, also with wall-guided 

direct injection;100 and a Robert Bosch paper suggesting a 13 percent NEDC gain for downsizing 

to a turbocharged DI engine, again with wall-guided injection.101 These reported fuel economy 

benefits show a wide range depending on the SGDI technology employed. 

The agencies reviewed estimates from the LD 2017-2025 final rule, the TSD, and 

existing public literature. The previous estimate from the MYs 2017-2025 suggested a 12 to 14 

percent effectiveness improvement, which included low friction lubricant (level one), engine 

friction reduction (level one), DCP, DVVL and SGDI, over baseline fixed-valve engines, similar 

to the estimate for Ford’s EcoBoost engine, which is already in production. Additionally, the 

agencies analyzed Ricardo vehicle simulation data and the 2015 NHTSA Technology Study for 

various turbocharged engine packages. Based on these data, and considering the widespread 

nature of the public estimates, the agencies assume that turbocharging and downsizing, would

provide a 16.4 percent effectiveness improvement over naturally aspirated engines as applied to 

Class 2b and 3 vehicles. 

We present cost estimates for this technology in Chapter 2.12 of this draft RIA.

Note that for this analysis we determined that this technology path is only applicable to 

heavy duty applications that have operating conditions more closely associated with light duty 

vehicles. This includes vans designed mainly for cargo volume or modest payloads having 

similar GCWR to light duty applications. These vans cannot tow trailers heavier than similar 

light duty vehicles and are largely already sharing engines of significantly smaller displacement 

and cylinder count compared to heavy duty vehicles designed mainly for trailer towing.
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2.5.1.9 Cooled Exhaust-Gas Recirculation

Cooled exhaust gas recirculation or Boosted EGR is a combustion concept that involves 

utilizing EGR as a charge diluent for controlling combustion temperatures and cooling the EGR 

prior to its introduction to the combustion system. Higher exhaust gas residual levels at part load 

conditions reduce pumping losses for increased fuel economy. The additional charge dilution 

enabled by cooled EGR reduces the incidence of knocking combustion and obviates the need for 

fuel enrichment at high engine power. This allows for higher boost pressure and/or compression 

ratio and further reduction in engine displacement and both pumping and friction losses while 

maintaining performance. Engines of this type use GDI and both dual cam phasing and discrete 

variable valve lift. The EGR systems considered in this proposal would use a dual-loop system 

with both high and low pressure EGR loops and dual EGR coolers. The engines would also use 

single-stage, variable geometry turbocharging with higher intake boost pressure available across 

a broader range of engine operation than conventional turbocharged SI engines. Such a system is 

estimated to be capable of an additional 3 to 5 percent effectiveness relative to a turbocharged, 

downsized GDI engine without cooled-EGR. The agencies have also considered a more 

advanced version of such a cooled EGR system that employs very high combustion pressures by

using dual stage turbocharging.

2.5.2 Diesel Engines 

Diesel engines in this class of vehicle have emissions characteristics that present 

challenges to meeting federal NOX emissions standards. It is a significant systems-engineering 

challenge to maintain the fuel consumption advantage of the diesel engine while meeting U.S. 

emissions regulations. Fuel consumption can be negatively impacted by emissions reduction 

strategies depending on the combination of strategies employed. Emission compliance strategies 

for diesel vehicles sold in the U.S. are expected to include a combination of improvements of 

combustion, air handling system, aftertreatment, and advanced system control optimization. 

These emission control strategies are being introduced on Tier 2 light-duty diesel vehicles today.

Some of the engine technologies are described in the Light-Duty Vehicle Greenhouse 

Gas Emission Standards and Corporate Average Fuel Economy Standards Joint Technical 

Support Document.102 Others are from the 2010 NAS Report, Technologies and Approaches to 

Reducing the Fuel Consumption of Medium- and Heavy-Duty Vehicles, and the 2015 NHTSA 

Technology Study. Several key advances in diesel technology have made it possible to reduce 

emissions coming from the engine prior to aftertreatment. These technologies include engine 

friction and parasitic loss reduction, improved fuel systems (higher injection pressure and 

multiple-injection capability), advanced controls and sensors to optimize combustion and 

emissions performance, higher EGR levels and EGR cooling to reduce NOX, and advanced 

turbocharging systems.

2.5.2.1 Low Friction Lubricants

Consistent with the discussion above for gasoline engines (see Section 2.5.1.1), the 

agencies are expecting some engine changes to accommodate low friction lubricants. Based on 

the light-duty 2014-2018 MY HD vehicle rulemaking, and previously-received confidential 
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manufacturer data, the agencies estimated the effectiveness of low friction lubricants to be 

between 0 to 1 percent.

We present cost estimates for this technology in Chapter 2.12 of this draft RIA. 

Based on a survey of the current powertrains being applied to the Class 2b and 3 segment 

and the level of powertrain sharing with the light duty vehicle market for these vehicles, the 

majority of light heavy duty gasoline engines in the 2014 Class 2b and 3 vehicle models are 

utilizing some form of low friction lubricants to achieve power and emission goals, and so this 

technology is considered to be in the baseline.

2.5.2.2 Engine Friction Reduction

Reduced friction in bearings, valve trains, and the piston-to-liner interface will improve 

efficiency. Friction reduction opportunities in the engine valve train and at its roller/tappet 

interfaces exist for several production engines. In virtually all production engines, the piston at 

its skirt/cylinder wall interface, wrist pin and oil ring/cylinder wall interface offer opportunities 

for friction reduction. Use of more advanced oil lubricant that could be available for production 

in the future may also eventually play a key role in reducing friction. Mechanical loads can also 

be reduced by converting the water, oil, and fuel pumps in the engine from fixed displacement to 

variable displacement. 

Estimations of fuel consumption improvements due to reduced engine friction from the 

2015 NHTSA Technology Study range from 1 percent to 2 percent. The agencies believe that 

this range is accurate.

We present cost estimates for this technology in Chapter 2.12 of this draft RIA. 

2.5.2.3 Turbocharger Technology

Compact two stage turbochargers can increase the boost level with wider operation range, 

thus improving engine thermal efficiency. Ford’s new developed 6.7L Scorpion engine features 

a twin-compressor turbocharger103. Cummins has also developed its own two stage 

turbochargers.104 It is expected that this type of technology will continue to be improved by

better system matching and development of higher compressor and turbine efficiency.

Based on the 2015 NHTSA Technology Study and previously-received confidential 

manufacturer data, the agencies estimate the fuel consumption reduction effectiveness of this 

technology to be between 2 and 3 percent.

We present cost estimates for this technology in Chapter 2.12 of this draft RIA.

2.5.2.4 Reduction of Parasitic Loads

Accessories that are traditionally gear- or belt-driven by a vehicle’s engine can be 

optimized and/or converted to electric power. Examples include the engine water pump, oil 

pump, fuel injection pump, air compressor, power-steering pump, cooling fans, and the vehicle’s 

air-conditioning system which can be converted to full electrically driven loads or an electro-
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mechanical arrangement that retains some mechanically connected aspects. Optimization and 

improved pressure regulation may significantly reduce the parasitic load of the water, air and 

fuel pumps. Electrification may result in a reduction in power demand, because electricallypowered accessories (such as the air compressor or power steering) operate only when needed if 

they are electrically powered, but they impose a parasitic demand all the time if they are enginedriven. In other cases, such as cooling fans or an engine’s water pump, electric power allows the 

accessory to run at speeds independent of engine speed, which can reduce power consumption. 

The 2015 NHTSA Technology Study used a 1 to 2 percent fuel consumption reduction for diesel 

engine parasitic improvements. 

We present cost estimates for this technology in Chapter 2.12 of this draft RIA.

2.5.2.5 Aftertreatment Improvements

The HD diesel pickup and van segment has largely adopted the SCR type of 

aftertreatment system to comply with criteria pollutant emission standards. As the experience 

base for SCR expands over the next few years, many improvements in this aftertreatment system 

such as construction of the catalyst, thermal management, and reductant optimization may result 

in a reduction in the amount of fuel used in the process. However, due to uncertainties with 

these improvements regarding the extent of current optimization and future criteria emissions 

obligations, the agencies are not considering aftertreatment improvements as a fuel-saving 

technology in the rulemaking analysis for HD pickups and vans.

2.5.3 Drivetrain

The agencies have also reviewed the transmission technology estimates used in the lightduty 2012-2016 MY vehicle rulemaking. In doing so, the agencies have considered or 

reconsidered all available sources and updated the estimates as appropriate. The section below 

describes each of the transmission technologies considered for this rulemaking.

2.5.3.1 Automatic 8-Speed Transmissions

Manufacturers can also choose to replace 6-speed transmissions with transmissions 

capable of 8-speeds or more. Additional ratios allow for further optimization of engine operation 

over a wider range of conditions, but this is subject to diminishing returns as the number of 

speeds increases. As additional gear sets are added (which may be necessary in some cases to 

achieve the higher number of ratios), additional weight and friction are introduced. Also, the 

additional shifting of such a transmission can be perceived as bothersome to some consumers, so 

manufacturers continue to develop strategies for smooth operation. 

As discussed in the heavy-duty 2014-2018 MY vehicle rulemaking along with 

confidential manufacturer data projected that 8-speed transmissions could incrementally reduce 

fuel consumption by 1 to 3 percent from a baseline 6-speed automatic transmission. The SwRI

report uses 2 to 3 percent fuel consumption reduction when replacing 6-speed baseline automatic 

transmissions with improved 8-speed automatic transmissions. 
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The agencies reviewed and revised these effectiveness estimates based on usage and 

testing methods for Class 2b and 3 vehicles. The agencies estimate the effectiveness for a 

conversion from a 6 to 8-speed transmission to be 2.7 percent.

We present cost estimates for this technology in Chapter 2.12 of this draft RIA.

2.5.3.2 High Efficiency Transmission

For this proposal, a high efficiency transmission refers to some or all of a suite of 

incremental transmission improvement technologies that should be available within the 2019 to 

2025 timeframe. The majority of these improvements address mechanical friction within the 

transmission. These improvements include but are not limited to: shifting clutch technology

improvements, improved kinematic design, dry sump lubrication systems, more efficient seals, 

bearings and clutches (reducing drag), component superfinishing and improved transmission 

lubricants.

2.5.3.3 Electric Power Steering (EPS)

Electric power steering (EPS) provides a potential reduction in CO2 emissions and fuel 

consumption over hydraulic power steering because of reduced overall accessory loads. This 

eliminates the parasitic losses associated with belt-driven power steering pumps which 

consistently draw load from the engine to pump hydraulic fluid through the steering actuation 

systems even when the wheels are not being turned. EPS is an enabler for all vehicle 

hybridization technologies since it provides power steering when the engine is off. EPS may be 

implemented on most vehicles with a standard 12V system. Some heavier vehicles such as Class 

2b and 3 may require a higher voltage system which may add cost and complexity.

The 2017 light-duty final rule estimated a one to two percent effectiveness based on the 

2002 NAS report, a Sierra Research report, and confidential manufacturer data. The SwRI report 

estimated 0.8 percent to 1 percent effectiveness. The agencies reviewed these SwRI 

effectiveness estimates and found them to be accurate, thus they have been retained for this 

proposal.

We present cost estimates for this technology in Chapter 2.12 of this draft RIA.

2.5.3.4 Improved Accessories

The accessories on an engine, including the alternator, coolant and oil pumps are 

traditionally mechanically-driven. A reduction in CO2 emissions and fuel consumption can be 

realized by driving them electrically, and only when needed (“on-demand”). 

Electric water pumps and electric fans can provide better control of engine cooling. For 

example, coolant flow from an electric water pump can be reduced and the radiator fan can be 

shut off during engine warm-up or cold ambient temperature conditions which would reduce 

warm-up time, reduce warm-up fuel enrichment, and reduce parasitic losses.

Indirect benefit may be obtained by reducing the flow from the water pump electrically

during the engine warm-up period, allowing the engine to heat more rapidly and thereby 
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reducing the fuel enrichment needed during cold operation and warm-up of the engine. Faster oil 

warm-up may also result from better management of the coolant warm-up period. Further benefit 

may be obtained when electrification is combined with an improved, higher efficiency engine 

alternator used to supply power to the electrified accessories. 

Intelligent cooling can more easily be applied to vehicles that do not typically carry

heavy payloads, so larger vehicles with towing capacity present a challenge, as these vehicles 

have high cooling fan loads.A However, towing vehicles tend to have large cooling system 

capacity and flow scaled to required heat rejection levels when under full load situations such as 

towing at GCWR in extreme ambient conditions. During almost all other situations, this design 

characteristic may result in unnecessary energy usage for coolant pumping and heat rejection to 

the radiator. 

The agencies considered whether to include electric oil pump technology for the 

rulemaking. Because it is necessary to operate the oil pump any time the engine is running, 

electric oil pump technology has insignificant effect on efficiency. Therefore, the agencies 

decided to not include electric oil pump technology.

2.5.3.5 Mild Hybrid (MHEV)

Mild hybrid systems offer idle-stop functionality and a limited level of regenerative 

braking and power assist. These systems replace the conventional alternator with a belt or crank 

driven starter/alternator and may add high voltage electrical accessories (which may include 

electric power steering and an auxiliary automatic transmission pump). The limited electrical 

requirements of these systems allow the use of lead-acid batteries or supercapacitors for energy

storage, or the use of a small lithium-ion battery pack. 

For the MHEV technology the agencies sized the system using a 7 kW starter/generator 

and 8 kWh Li-ion battery pack. The estimates were developed by Argonne National Laboratory

as a supplement to the 2015 NHTSA Technology Study, resulting in an effectiveness range of 4

to 5 percent depending on the vehicle’s engine. We present cost estimates for this technology in 

Chapter 2.12 of this draft RIA.

2.5.3.6 Strong Hybrid (SHEV)

A hybrid vehicle is a vehicle that combines two significant sources of propulsion energy, 

where one uses a consumable fuel (like gasoline), and one is rechargeable (during operation, or 

by another energy source). Hybrid technology is well established in the U.S. market and more 

manufacturers are adding hybrid models to their lineups. Hybrids reduce fuel consumption 

through three major mechanisms:

 The internal combustion engine can be optimized (through downsizing, modifying the 

operating cycle, or other control techniques) to operate at or near its most efficient 

 

A

In the CAFE model, improved accessories refers solely to improved engine cooling. However, EPA has included 

a high efficiency alternator in this category, as well as improvements to the cooling system.
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point more of the time. Power loss from engine downsizing can be mitigated by

employing power assist from the secondary power source.

 Some of the energy normally lost as heat while braking can be captured and stored in 

the energy storage system for later use.

 The engine is turned off when it is not needed, such as when the vehicle is coasting or 

when stopped.

Hybrid vehicles utilize some combination of the three above mechanisms to reduce fuel 

consumption and CO2 emissions. The effectiveness of fuel consumption and CO2 reduction 

depends on the utilization of the above mechanisms and how aggressively they are pursued. One 

area where this variation is particularly prevalent is in the choice of engine size and its effect on 

balancing fuel economy and performance. Some manufacturers choose not to downsize the 

engine when applying hybrid technologies. In these cases, performance is vastly improved, 

while fuel efficiency improves significantly less than if the engine was downsized to maintain 

the same performance as the conventional version. The non-downsizing approach is used for 

vehicles like trucks where towing and/or hauling are an integral part of their performance 

requirements. In these cases, if the engine is downsized, the battery can be quickly drained 

during a long hill climb with a heavy load, leaving only a downsized engine to carry the entire 

load. Because towing capability is currently a heavily-marketed truck attribute, manufacturers 

are hesitant to offer a truck with downsized engine which can lead to a significantly diminished 

towing performance when the battery state of charge level is low, and therefore engines are 

traditionally not downsized for these vehicles.

Strong Hybrid technology utilizes an axial electric motor connected to the transmission 

input shaft and connected to the engine crankshaft through a clutch. The axial motor is a 

motor/generator that can provide sufficient torque for launch assist, all electric operation, and the 

ability to recover significant levels of braking energy. 

For SHEV, the agencies also relied on the study by Argonne National Laboratory to 

supplement the 2015 NHTSA Technology Study to determine that the effectiveness of these 

systems in terms of CO2 reduction. For the SHEV technology the agencies sized the system 

using a 50 kW starter/generator and a70 kWh Li-ion battery pack. The estimates resulted in an 

effectiveness range of 18 to 22 percent depending on the engine. The estimates assume no engine 

downsizing in order to maintain vehicle performance and/or maintain towing and hauling 

performance.

We present cost estimates for this technology in Chapter 2.12 of this draft RIA.

2.5.4 Aerodynamics

Aerodynamic drag is an important aspect of the power requirements for Class 2b and 3 

trucks. Because aerodynamic drag is a function of the cube of vehicle speed, small changes in 

the aerodynamics of a Class 2b and 3 can reduce drag, fuel consumption, and GHG emissions. 

Some of the opportunities to reduce aerodynamic drag in Class 2b and 3 vehicles are similar to 

those in Class 1 and 2 (i.e., light-duty) vehicles. In general, these transferable features make the 
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cab shape more aerodynamic by streamlining the airflow over the bumper, grill, windshield, 

sides, and roof. Class 2b and 3 vehicles may also borrow from light-duty vehicles certain drag 

reducing accessories (e.g., streamlined mirrors, operator steps, and sun visors). The great variety 

of applications for Class 2b and 3 trucks result in a wide range of operational speed profiles (i.e., 

in-use drive cycles) and functional requirements (e.g., shuttle buses that must be tall enough for 

standing passengers, trucks that must have racks for ladders). This variety makes it challenging 

to develop aerodynamic solutions that consider the entire vehicle.

Many factors affect a vehicle’s aerodynamic drag and the resulting power required to 

move it through the air. While these factors change with air density and the square and cube of 

vehicle speed, respectively, the overall drag effect is determined by the product of its frontal area 

and drag coefficient. Reductions in these quantities can therefore reduce fuel consumption and 

CO2 emissions. Although frontal areas tend to be relatively similar within a vehicle class 

(mostly due to market-competitive size requirements), significant variations in drag coefficient 

can be observed. Significant changes to a vehicle’s aerodynamic performance may need to be 

implemented during a redesign (e.g., changes in vehicle shape). However, shorter-term 

aerodynamic reductions, with a somewhat lower effectiveness, may be achieved through the use 

of revised exterior components (typically at a model refresh in mid-cycle) and add-on devices 

that are currently being applied. The latter list would include revised front and rear fascias, 

modified front air dams and rear valances, addition of rear deck lips and underbody panels, and 

lower aerodynamic drag exterior mirrors.

For this proposal, the agencies considered two levels of aero improvements. The first 

level includes such body features as air dams, tire spats, and perhaps one underbody panel 

resulting in a 5 percent aerodynamic drag reduction. The agencies estimated the CO2 and fuel 

consumption effectiveness of this first level of aerodynamic drag at 0.75 percent.

The second level which includes the features of level 1 plus additional body features such 

as active grille shuttersB, rear visors, larger under body panels or low-profile roof racks resulting 

in a 10 percent aerodynamic drag reduction. The agencies estimated the CO2 and fuel 

consumption effectiveness of this second level of aerodynamic drag at 1.5 percent. We present 

cost estimates for this technology in Chapter 2.12 of this draft RIA.

2.5.5 Tires

Typically, tires used on Class 2b/3 vehicles are not designed specifically for the vehicle. 

These tires are designed for broader use and no single parameter is optimized. Similar to 

vocational vehicles, the market has not demanded tires with improved rolling resistance thus far; 

therefore, manufacturers have not traditionally designed tires with low rolling resistance for 

Class 2b/3 vehicles. The agencies believe that a regulatory program that incentivizes the 

optimization of tire rolling resistance, traction and durability can bring about GHG emission and 

fuel consumption reductions of 1.1 percent from this segment based on a 10 percent reduction in 

rolling resistance.

 

B

For details on how active aerodynamics are considered for off-cycle credits, see TSD Chapter 5.2.2. 
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We present cost estimates for this technology in Chapter 2.12 of this draft RIA. 

2.5.6 Mass Reduction

Mass reduction is a technology that can be used in a manufacturer’s strategy to meet the 

Heavy Duty Greenhouse Gas Phase 2 standards. Vehicle mass reduction (also referred to as 

“down-weighting” or ‘light-weighting”), decreases fuel consumption and GHG emissions by

reducing the energy demand needed to overcome inertia forces, and rolling 

resistance. Automotive companies have worked with mass reduction technologies for many

years and a lot of these technologies have been used in production vehicles. The weight savings 

achieved by adopting mass reduction technologies offset weight gains due to increased vehicle 

size, larger powertrains, and increased feature content (sound insulation, entertainment systems, 

improved climate control, panoramic roof, etc.). Sometimes mass reduction has been used to 

increase vehicle towing and payload capabilities.

Manufacturers employ a systematic approach to mass reduction, where the net mass 

reduction is the addition of a direct component or system mass reduction, also referred to as 

primary mass reduction, plus the additional mass reduction taken from indirect ancillary systems 

and components, also referred to as secondary mass reduction or mass compounding. There are 

more secondary mass reductions achievable for light-duty vehicles compared to heavy-duty 

vehicles, which are limited due to the higher towing and payload requirements for these vehicles. 

Mass reduction can be achieved through a number of approaches, even while maintaining 

other vehicle functionalities. As summarized by NAS in its 2011 light duty vehicle report, there 

are two key strategies for primary mass reduction: 1) changing the design to use less material; 2) 

substituting lighter materials for heavier materials.105

The first key strategy of using less material compared to the baseline component can be 

achieved by optimizing the design and structure of vehicle components, systems and vehicle 

structure. Vehicle manufacturers have long used these continually-improving CAE tools to 

optimize vehicle designs. For example, the Future Steel Vehicle (FSV) project sponsored by 

WorldAutoSteel used three levels of optimization: topology optimization, low fidelity 3G 

(Geometry Grade and Gauge) optimization, and subsystem optimization, to achieve 30 percent 

mass reduction in the body structure of a vehicle with a mild steel unibody structure.106 Using 

less material can also be achieved through improving the manufacturing process, such as by 

using improved joining technologies and parts consolidation. This method is often used in 

combination with applying new materials.

The second key strategy to reduce mass of an assembly or component involves the 

substitution of lower density and/or higher strength materials. Material substitution includes 

replacing materials, such as mild steel, with higher-strength and advanced steels, aluminum, 

magnesium, and composite materials. In practice, material substitution tends to be quite specific 

to the manufacturer and situation. Some materials work better than others for particular vehicle 

components, and a manufacturer may invest more heavily in adjusting to a particular type of 

advanced material, thus complicating its ability to consider others. The agencies recognize that 

like any type of mass reduction, material substitution has to be conducted not only with 

consideration to maintaining equivalent component strength, but also to maintaining all the other 
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attributes of that component, system or vehicle, such as crashworthiness, durability, and noise, 

vibration and harshness (NVH).

If vehicle mass is reduced sufficiently through application of the two primary strategies 

of using less material and material substitution described above, secondary mass reduction 

options may become available. Secondary mass reduction is enabled when the load requirements 

of a component are reduced as a result of primary mass reduction. If the primary mass reduction 

reaches a sufficient level, a manufacturer may use a smaller, lighter, and potentially more 

efficient powertrain while maintaining vehicle acceleration performance. If a powertrain is 

downsized, a portion of the mass reduction may be attributed to the reduced torque requirement 

which results from the lower vehicle mass. The lower torque requirement enables a reduction in 

engine displacement, changes to transmission torque converter and gear ratios, and changes to 

final drive gear ratio. The reduced powertrain torque enables the downsizing and/or mass 

reduction of powertrain components and accompanying reduced rotating mass (e.g., for 

transmission, driveshafts/halfshafts, wheels, and tires) without sacrificing powertrain durability. 

Likewise, the combined mass reductions of the engine, drivetrain, and body in turn reduce 

stresses on the suspension components, steering components, wheels, tires, and brakes, which 

can allow further reductions in the mass of these subsystems. Reducing the unsprung masses 

such as the brakes, control arms, wheels, and tires further reduce stresses in the suspension 

mounting points, which allows for further optimization and potential mass reduction. However, 

pickup trucks have towing and hauling requirements which must be taken into account when 

determining the amount of secondary mass reduction that is possible and so it is less than that of 

passenger cars.

Ford’s MY 2015 F-150 is one example of a light duty manufacturer who has begun 

producing high volume vehicles with a significant amount of mass reduction identified, 

specifically 250 to 750 lb per vehicle.107 The vehicle is an aluminum intensive design and 

includes an aluminum cab structure, body panels, and suspension components, as well as a high 

strength steel frame and a smaller, lighter and more efficient engine. The Executive Summary

to Ducker Worldwide’s 2014 report states that state that the MY 2015 F-150 contains 1080 

pounds of aluminum with at least half of this being aluminum sheet and extrusions for body and 

closures.108 Ford engine range for its light duty truck fleet includes a 2.7L EcoBoost V-6. It is 

possible that the strategy of aluminum body panels would be applied to the heavy duty F-250 and 

F-350 versions when they are redesigned.109 

The US EPA recently completed a multi-year study with FEV North America, Inc. on the 

lightweighting of a light-duty pickup truck, a 2011 GMC Silverado, titled “Mass Reduction and 

Cost Analysis –Light-Duty Pickup Trucks Model Years 2020-2025”.110 Results contain a cost 

curve for various mass reduction percentages with the main solution being evaluated for a 21.4 

percent (511 kg/1124 lb) mass reduction resulting in an increased direct incremental 

manufacturing cost of $2228. In addition, the report outlines the compounding effect that occurs 

in a vehicle with performance requirements including hauling and towing. Secondary mass 

evaluation was performed on a component level based on an overall 20 percent vehicle mass 

reduction. Results revealed 84 kg of the 511 kg, or 20 percent, were from secondary mass 

reduction. Information on this study is summarized in SAE paper 2015-01-0559. The US DOT 

has also sponsored an on-going pickup truck lightweighting project. This project uses a more 

recent baseline vehicle, a MY 2014 GMC Silverado, and the project will be finished by early 
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2016. Both projects will be utilized for the light-duty GHG Phase 2 Midterm Evaluation mass 

reduction baseline characterization and may be used to update assumptions of mass reduction for 

HD pickups and vans for the final Phase 2 rulemaking.

In order to determine if technologies identified on light duty trucks are applicable to 

heavy-duty pickups, the U.S. EPA also contracted with FEV North America, Inc. to perform a 

scaling study in order to evaluate the technologies identified for the light-duty truck would be 

applicable for a heavy-duty pickup truck, in this study a Silverado 2500, a Mercedes Sprinter and 

a Renault Master. This report is currently being drafted and will be peer reviewed and finalized 

between the NPRM and FRM. In general, the heavy-duty pickup truck scaling study reveals 

results similar to the light-duty truck study; however, the mass reduction and cost for the Sprinter 

and Master were less in percent mass reduction and with much higher costs than the heavy-duty 

pickup truck. The specific results will be included in the final rulemaking. 

We present cost estimates for this technology in Chapter 2.12 of this draft RIA.

2.6 Technology Application– SI Engines

This section summarizes the technologies the agencies project as a feasible path to 

meeting the proposed engine standards for spark-ignition engines used in vocational vehicles –

that is engines that are engine-certified and intended for vocational vehicles that will be GEMcertified. These standards apply with respect to emissions measured over the FTP test cycle.

This cycle is described in Chapter 3.1. See Chapter 2.5 for spark-ignited engine technologies 

projected for the proposed Phase 2 HD pickup and van vehicle standards.

Heavy-duty spark-ignited (SI) engines are used in almost 30 percent of vocational 

vehicles. Operators that choose gasoline engines do so for reasons similar to those for HD 

complete pickups and vans. Gasoline engines have the advantage of being less expensive and 

lower weight than diesels, but tend to also be less durable and have higher fuel consumption. 

Thus, gasoline engines are most likely to be purchased for applications with lower annual VMT, 

where fuel costs are less important than upfront costs. 

Today some SI-powered vocational vehicles are sold as incomplete vehicles by a 

vertically integrated chassis manufacturer, where the Phase 1 rules allow manufacturers to 

choose to certify incomplete vehicles with weight ratings between 8,501 and 14,000 lbs GVWR 

as vocational vehicles under the GEM certification procedures including separate engine GHG 

certification, if the engine is also engine-certified for criteria pollutants.

C

In this case, vertically

integrated means both the engine and chassis are manufactured by the same entity.

In Phase 1 we generally required that vehicles that are chassis-certified for criteria 

pollutants be chassis-certified for GHGs and fuel consumption, and likewise that vehicles with 

engines certified for criteria pollutants (which in this case would be engines installed in 

vocational vehicles exclusively) be certified to the vocational vehicle standards for GHGs and 

fuel consumption, with minor exceptions. We believe that this approach involving consistent 

 

C

See 76 FR 57106 (September 15, 2011) and 40 CFR 1037.104(f)
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chassis- and engine-certification for criteria pollutants and GHG’s is the most sensible way to 

structure a program to minimize both the testing burden and the potential for gaming.

There is a Phase 1 optional provision that allows manufacturers to certify Class 4 or 5 

(14,001 to 19,500 lb GVWR) complete or incomplete vehicles to be chassis certified and thereby

included within the Class 2b/3 fleet average.

D

 In Section XIV of the preamble to this 

rulemaking, EPA is requesting comment on some specific issues related to chassis certification 

of vehicles over 14,000 lbs GVWR for criteria pollutants. As adopted in Phase 1, the engines in 

these vehicles must be engine-certified for criteria pollutants, but the manufacturers may include 

the vehicles in their fleet average standard and annual compliance GHG calculations, using the 

same certification and compliance provisions as for the lighter vehicles. Such vehicles are not 

required to meet the vocational vehicle standards. Because sales volumes of Class 4 and 5 trucks 

are relatively small, and because we expect these Class 4 and 5 and Class 2b and 3 trucks to 

generally use the same technologies and face roughly the same technology challenge in meeting 

their standards targets, we do not believe that this provision dilutes the stringency of the fleet 

average standards.

Another, less common way that SI-powered vocational vehicles are built is by a nonintegrated chassis manufacturer purchasing an engine from a company that also produces 

complete and/or incomplete HD pickup trucks and vans. The Phase 1 program allows SI engine 

manufacturers to sell these so-called “loose” SI engines to other chassis manufacturers for use in 

vocational vehicles. The primary certification path designed in the Phase 1 program in this 

scenario is for the “loose” engine to be engine certified and the vehicle to be GEM certified 

under the GHG rules. This is common practice for CI engines, and in Phase 2 the agencies 

propose to continue this as the primary certification path for SI engines intended for vocational 

vehicles.

In Phase 1 we adopted a special provision aimed at simplifying compliance for 

manufacturers of complete HD pickups and vans that also sell a relatively small number of loose 

engines. This flexibility provision enables these manufacturers to avoid meeting the separate SI 

engine standard, instead averaging them into the applicable HD pickup and van fleet-wide 

average.ELoose engine sales account for the vast majority of CI-powered vocational vehicles, 

but represent a very small fraction of the SI-powered vocational vehicle market. 

The SI engines certified and sold as loose engines into the heavy-duty vocational vehicle

market are typically large V8 and V10 engines produced by General Motors and Ford. The 

number of engine families certified in the past for this segment of vehicles is very limited and 

has ranged between three and five engine models.F Unlike the heavy-duty diesel engines typical 

of this segment that are built for vocational vehicles, these SI engines are primarily developed for 

chassis-certified heavy-duty pickup trucks and vans, but are also installed in incomplete 

vocational vehicles.

 

D

See 76 FR 57259-57260, September 15, 2011 and 78 FR 36374, June 17, 2013

E

See 40 CFR 1037.150(m) and 49 CFR 535.5(a)(7). 

F

See EPA’s heavy-duty engine certification database at http://www.epa.gov/otaq/certdata.htm#largeng.
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Under this special Phase 1 provision, these loose engines need not be certified to enginebased GHG and fuel consumption standards, but instead may be treated under the regulations as 

though they are additional sales of the manufacturer’s complete pickup and van products, on a 

one-for-one basis. The pickup/van vehicle so chosen must be the vehicle with the highest 

emission test weight that uses the engine (as this vehicle is likely to have the highest GHG 

emissions and fuel consumption).G However, if this vehicle is a credit-generator under the HD 

pickup and van fleet averaging program, no credits would be generated by these engine-asvehicle contributors to the fleet average; they would be treated as just achieving the target 

standard. If, on the other hand, the vehicle is a credit-user, the appropriate number of additional 

credits would be needed to offset the engine-as-vehicle contributors. The purchaser of the 

engine would treat it as any other certified engine, and would still need to meet applicable 

vocational vehicle standards for the vehicles in which the engine is installed. 

2.6.1 Defining the Baseline Engines

In deriving the stringency of the proposed Phase 2 SI engine standard, the agencies first 

reviewed the technology that was presumed in the MY 2010 Phase 1 baseline and the technology

that was projected would be adopted to meet the MY 2016 SI engine standard, finalized as part 

of the Phase 1 program. Engines certified to this standard would represent a logical level at 

which to set a Phase 2 baseline performance level. 

The agencies finalized MY 2016 standards that require manufacturers to achieve a five 

percent reduction in CO2 compared to the Phase 1 MY 2010 baseline. That MY 2010 baseline 

engine was described in the Phase 1 preamble at Section III.B.2.a.iii, as a naturally aspirated, 

overhead valve V8 engine. H

In deriving the stringency of the MY 2016 gasoline engine standards, the agencies 

projected 100 percent adoption of engine friction reduction, coupled cam phasing, and 

stoichiometric gasoline direct injection (SGDI) to produce an overall five percent reduction from 

the reference engine, over the engine FTP test cycle. Table 2-4 presents the technologies 

projected to be present on an engine following this technology path.

Table 2-4 MY 2016 Technology Projection for SI Engines

TECHNOLOGY ADOPTION 

RATE

Coupled Cam Phasing 100%

Engine friction reduction 100%

Gasoline direct injection 100%

In deciding whether to consider the above package as representing the Phase 2 baseline 

performance of SI engines, the agencies reviewed available certification information and 

 

G Equivalent test weight is defined at 40 CFR 1037.104(d)(11) and is determined based on a vehicle’s adjusted 

loaded vehicle weight as specified in 40 CFR 86.129, except that for vehicles over 14,000 pounds, this may be 

rounded to the nearest 500 pound increment.

H

See 76 FR 57231
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consulted with stakeholders to determine the degree to which these projections match with 

engines being produced today and engine product plans during the Phase 1 time frame. The 

agencies have learned that no SI engine manufacturer has applied SGDI to this type of engine to 

date, though cam phasing and engine friction reduction are widely being employed. 

Furthermore, no SI engine manufacturer has yet certified an engine to the future MY 2016 SI 

engine standard, and the agencies do not have specific information about what alternate 

technology paths the manufacturers may take.

Another possible method to establish a Phase 2 SI engine baseline performance level 

would be to assess the engines that are currently being produced for complete HD SI pickup 

trucks. These vehicles are powered by engines that closely resemble engines intended for

vocational vehicles. Further, cab-complete and box-delete vehicles sold into vocational 

applications are often derived from HD pickup truck chassis. The SI engine technologies 

assessed for the reference fleet for the HD pickup and van program are described in the preamble 

Section VI and in the draft RIA Chapter 10. As described in the draft RIA Chapter 10, vehicle 

manufacturers typically offer few models (i.e. only a pickup truck and/or a cargo van) and while 

there are a large number of variants of each model, the degree of component sharing across the 

variants can make diversified technology application either economically impractical or 

impossible. Similarly, these manufacturers produce a limited number of engines and tune them 

for slight variants in output for a variety of car and truck applications. Manufacturers limit 

complexity in their engine portfolio for much the same reason as they limit complexity in vehicle 

variants: they face engineering manpower limitations, and supplier, production and service costs 

that scale with the number of parts produced.

The SI engine technologies that were considered in developing the proposed Phase 2 HD 

pickup truck standards and their projected adoption rates are shown in Table 2-5, as taken from 

Table VI-10 of the preamble. The vehicle-level technologies considered for the gasoline HD 

pickup truck standards and shown in Table VI-10 are not presented here. Considering the abovedescribed constraints on engine technology adoption, it’s not surprising the projections for 

technology packages for the Phase 2 HD pickup and van program include a limited set of SI

engine technologies for HD pickup trucks. 

Table 2-5 CAFE Model Technology Adoption Rates for HD Gasoline Pickup Trucks

TECHNOLOGY REFERENCE CASEaPROPOSAL (2.5% PER YEAR)b

2018 With strong 

hybrids

Without strong 

hybrids

Level 1 Low friction lubricants and Engine 

friction reduction

100% 100% 100%

Level 2 Low friction lubricants and Engine 

friction reductionc

35 to 40% 100% 100%

Cylinder deactivation (overhead valve) 8 to 9% 56% 56%

Variable valve timing 0% 56% 56%

Gasoline direct injection 0% 0% 56%

Notes:

a These values are taken from a spreadsheet file with CAFE model output, representing technology adoption rates 

projected in the no-action scenario.

b These values are taken from Section VI.C.8, Table VI-10 of the preamble, and represent technology adoption rates 

projected in the flat baseline scenario.
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c Level 2 friction reduction as shown here is incremental to Level 1 friction reduction.

In comparing the technologies and projected adoption rates in Table 2-4 and Table 2-5, 

there are notable differences between what is projected for complete vehicles in MY 2018 and 

what was projected for engine-certified engines in MY 2016. The CAFE model used by the 

agencies treats different types of variable valve timing technologies as a group, so that coupled 

cam phasing would be included under the heading variable valve timing. The only type of 

variable valve timing that is feasible on an overhead valve engine is coupled cam phasing.I In

light of the differences in projected adoption rates of SGDI and variable valve timing, there is 

uncertainty about the technology pathways that may be taken by SI engine manufacturers in the 

Phase 1 time frame. Thus, the agencies have concluded that it would be more appropriate to set 

the Phase 2 baseline performance level equal to the Phase 1 MY 2016 engine standard, rather 

than a performance level representing more or less technology than is represented by that 

standard. 

2.6.2 Phase 2 Technology Feasibility and Effectiveness

A detailed description of many technologies potentially available to improve the fuel 

efficiency of SI engines can be found above in draft RIA Chapter 2.2. In deriving the stringency

of the proposed Phase 2 SI engine standard, the agencies excluded the technologies already

presumed in the baseline engine (see Table 2-4), and rejected technologies not considered as part 

of the proposed HD pickup truck standards (see Table 2-5). The agencies have not identified a 

single SI engine technology that we believe belongs on engine-certified vocational engines that 

we do not also project to be used on complete heavy-duty pickups and vans. 

It is also important to consider how these engines will be used. Engines in pickup trucks 

are likely to be driven very differently than engines in vocational vehicles. For example, a 

complete pickup truck may do an extensive amount of towing while vocational vehicles rarely 

tow trailers. Further, the most popular applications for SI engines in vocational vehicles are 

motor homes and school buses, which each have very different driving patterns, which also differ 

from those of pickup trucks. The agencies believe these differences in application and intended 

use may lead manufacturers to offer engines that may have small differences, and that such 

differences would be captured by the vehicle test procedures applicable to those applications. 

Specifically, complete HD pickups are certified using a chassis test procedure that is described in 

40 CFR part 86, while vocational vehicles are certified using the GEM vehicle simulation tool 

described in 40 CFR part 1037. 

In light of the market structure described above in Chapter 2.6, when the agencies 

considered the feasibility of more stringent Phase 2 standards for SI vocational engines, we 

identified the following key questions:

1. Will there be technologies available that could reduce in-use emissions from 

vocational SI engines?

 

I

See Preamble at Section VI.C.5(a)(iv)
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2. Would these technologies be applied to complete vehicles and carried-over to 

engine certified engines without a new standard?

3. Would these technologies be applied to meet the vocational vehicle standards?

4. What are the drawbacks associated with setting a technology-forcing Phase 2 

standard for SI engines?

With respect to the first question, the agencies have identified Level 2 lubricants, Level 2 

engine friction reduction, and cylinder deactivation as technologies available to be considered for

a Phase 2 SI engine standard. With respect to the second question, based on Table 2-5, we 

project that these may be applied to complete vehicles. The agencies have further determined 

that to the extent these technologies would be viable for complete vehicles, they would also be 

applied to engine-certified engines, to the extent they would not detract from performance 

required by vocational vehicle owners. 

With respect to the third question, we believe that to the extent these engine technologies 

are viable and effective, they would be applied to meet the GEM-based standards for vocational 

vehicles. As described elsewhere in this proposal, the Phase 2 GEM would recognize engine 

technologies through interpolation of engine data generated by engine manufacturers and 

submitted to EPA and NHTSA for vehicle certification. Thus, it would be possible for cylinder 

deactivation to be recognized over the vocational vehicle GEM test cycles, if it were present on a 

vocational SI engine.

Nevertheless, significant uncertainty remains about how much benefit would be provided 

by the identified Phase 2 candidate SI engine technologies. It is possible that the combined 

improvement of these technologies would be one percent or less. The degree of improvement for 

friction reduction is generally not cycle-dependent, but the effectiveness of cylinder deactivation 

is highly cycle-dependent.

It appears the fourth question regarding drawbacks is the most important. The agencies 

could propose a technology forcing standard for engine-certified SI engines based on a 

projection of each of these identified candidate technologies being effective for all engines. 

However, the agencies see value in setting the standard at a level that would not require every

projected technology to work as expected. Effectively requiring technologies to match our 

current projections would create the risk that the standard would not be feasible if even a single 

one of the technologies failed to match our projections. This risk is amplified for SI engines 

because of the very limited product offerings, which provide far fewer opportunities for 

averaging than exist for CI engines. 

Given the relatively small improvement projected, and the likelihood that most or all of 

this improvement would result anyway from the complete HD pickup and van standards and the 

vocational vehicle standards, we do not believe such risk is justified at the engine level.

Because one of the guiding principles of the Phase 2 program is maintaining customer 

choice, we have a strong interest in structuring a program that would enable SI engine 

manufacturers to continue supplying loose engines to the vocational vehicle market. For the 

reasons discussed above, rather than proposing a more stringent engine standard, the agencies are 

proposing to maintain the MY 2016 fuel consumption and CO2 emission standards for SI engines 
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for use in vocational vehicles: 7.06 gallon/100 bhp-hr and 627 g CO2/bhp-hr, as measured over 

the Heavy-duty FTP engine test cycle. 

In the preamble Section V and the draft RIA Chapter 2.9, the agencies describe the 

vocational vehicle standards, including details about ways we considered SI engine technologies 

such as advanced friction reduction over the GEM vehicle test cycles, as part of the proposed 

Phase 2 vocational vehicle standards. 

2.7 Technology Application and Estimated Costs – CI Engines

2.7.1 Phase 1 Engines

For analytical purposes, the agencies are projecting the technologies that may be used to 

meet the 2017 diesel engine standard. This technology package serves as a baseline for costs for 

this proposal. The agencies project that such engines will be equipped with an aftertreatment 

system which meets EPA’s 0.20 grams of NOX/bhp-hr standard with a selective catalytic 

reduction (SCR) system along with EGR and meets the PM emissions standard with a diesel 

particulate filter (DPF) with active regeneration. The following discussion of technologies 

describes improvements over the 2017 model year engine performance, unless otherwise noted. 

The CO2 performance over the FTP as well as SET for the baseline engines were 

developed through manufacturer reporting of CO2 in their non-GHG certification applications for 

2014 model year. This data was carefully considered to ensure that the baseline represented an 

engine meeting the 0.20 g/bhp-hr NOX standard. For those engines that were not at this NOX

level or higher, the agencies derived a CO2 correction factor to bring them to a 0.20 g/bhp-hr 

NOX emissions rate. The CO2 correction factor is derived based on available experimental data 

obtained from manufacturers and public literature. The agencies then sales-weighted the CO2

performance to derive a baseline CO2 performance for each engine subcategory.

In order to establish baseline SET performance for the tractor engine and FTP 

performance for the vocational, several sources were considered. Some engine manufacturers 

provided the agencies with SET modal and FTP results or fuel consumption maps to represent 

their engine ranging from 2011 to 2013 model year engine fuel consumption performance. As a 

supplement to this, complete engine map CO2 data (including SET modes) acquired in EPA test 

cells as well as those obtained from Southwest Research Institute under the agency contract were 

also considered. Those maps are subsequently adjusted to represent 2021 and 2024 model year 

engine maps by using predefined technologies that are being used in current 2014 production.

In summary, the baseline CO2 performance for each diesel engine category is included in 

Table 2-6.

Table 2-6 Baseline CO2 Performance (g/bhp-hr)

LHDD - FTP MHDD - FTP HHDD - FTP HHDD - SET HHDD - SET

576 576 555 487 460
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2.7.2 Individual Technology Feasibility and Cost

The cost for combustion system optimization includes costs associated with several 

individual technologies, specifically, improved cylinder head, turbo efficiency improvements, 

EGR cooler improvements, higher pressure fuel rail, improved fuel injectors and improved 

pistons. The cost estimates for each of these technologies are presented in Section 2.12 of this 

draft RIA for heavy HD, medium HD and light HD engines, respectively.

The agencies have included the costs of model-based control development in the research 

and development costs applied separately to each engine manufacturer.

2.7.3 Test Cycle Weighting

The current SET modes used for tractor engine certification in Phase 1 has relative large 

weighting in C speed as shown in the middle column of the following table:

Table 2-7 SET Modes Weighting Factors

SPEED/% LOAD WEIGHTING FACTOR IN 

PHASE 1 (%)

PROPOSED WEIGHTING 

FACTOR IN PHASE 2 (%)

Idle 15 12

A, 100 8 9

B, 50 10 10

B, 75 10 10

A, 50 5 12

A, 75 5 12

A, 25 5 12

B, 100 9 9

B, 25 10 9

C, 100 8 2

C, 25 5 1

C, 75 5 1

C, 50 5 1

Total 100 100

A: 23 45

B: 39 38

C: 23 5

It can be seen from the above table that 23 percent weighting is in C speed, which is 

typically in the range of 1800 rpm for HHD engines. However, many of today’s HHD engines

do not commonly operate in such a high speed in real world driving conditions, specifically 

during cruise vehicle speed between 55 and 65 mph. The agencies received confidential 

business information from a few vehicle manufacturers that support this observation. 

Furthermore, one of the key technology trends is to down speed, moving the predominant engine 

speed from the range of 1300-1400 rpm to the range of 1150-1200 rpm at vehicle speed of 

65mph. This trend would make the predominant engine speed even further away from C speed. 

Therefore, it can be argued that, if the current SET weighting factors were retained in Phase 2, 

the test would even more poorly reflect real-world driving operations. Further, some

technologies developed the standard may not be as effective over real world driving conditions, 

while technologies that would be more likely to deliver real world reductions could be under-
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represented on the test. Accordingly, the agencies are proposing to adjust the weighting of the 

various modes in the SET cycle as presented in the third column of Table 2-7.

As shown, the new proposed SET mode weighting basically would move most of the C 

weighting to A speed. It also would slightly reduce the weighting factor on the idle speed.

These proposed values are based on the confidential business information obtained from vehicle 

manufacturers. 

2.7.4 Technology Packages

The agencies assessed the impact of technologies over each of the SET modes to project 

an overall improvement for a tractor engine. The agencies considered improvements in parasitic 

and friction losses through piston designs to reduce friction, improved lubrication, and improved 

water pump and oil pump designs to reduce parasitic losses. The aftertreatment improvements 

are available through additional improvements to lower backpressure of the systems, further 

optimization of the engine-out NOX levels, and further reduction on ammonia slop out of SCR. 

Improvements to the EGR system and air flow through the intake and exhaust systems, along 

with turbochargers, can also produce engine efficiency improvements. Improvement of 

combustion and controls can reduce fuel consumption of the engine. Engine downsizing is part 

of consideration for improving efficiency, specifically when this technology is used together 

with down speeding. Although one of the most effective technologies to improve engine 

efficiency is the use of waste heat recovery (WHR) with Rankine cycle concept, the agencies do 

not project that this technology will have noticeable market penetration until MY 2024. The 

reason is that this type of WHR system involves many components that require extensive field 

testing to assure reliability. See Chapter 2.3.9 above. The high technology cost, longer pay back 

period (if the cost and benefit of using WHR is considered in isolation), concern about 

commercial acceptance (given the technology complexity, cost, concern about demurrage costs 

and warranty claims in early model years) again point to longer necessary lead time for 

introducing this technology. During the stringency development based on various technologies, 

the agencies received strong supports from various stakeholders, provided as many confidential 

business information (CBI). Table 2-8 lists those potential technologies together with the 

agencies’ estimated market penetration for tractor engine. However, as can be seen from this 

table, the agencies would not be able to release the more detailed numbers along each mode of 

13 SET modes to justify our stringency proposal due to nature of CBI. It should be pointed out 

that the stringency developed in Table 2-8 is based on the new proposed reweighting SET 

factors. 

With respect to market penetration, the agencies use the current market information and 

literature values to project what would be in the time frame beyond 2021. For example, only

Daimler uses turbo-compound in their DD15 and DD16 engines currently. However, they are 

phasing out turbo-compound with the replacement of asymmetric turbo technology for most 

applications. In the meantime, Volvo just announced that they would put their new developed 

turbo-compound technology into the market. Combining both manufacturers’ market shares, the 

agencies estimate 5 percent market share in 2021. With the assumption that this technology

could prove to be cost effective and be accepted by market well, more production from existing 

manufacturers or even some of other manufacturers could adopt this technology in some of their 

trucks, and therefore the market share could pick up 10 percent after 2024. The agencies assume 
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that the WHR with Rankine cycle will pick up momentum with more lead time because of the 

nature of high performance. However, as pointed out in Chapter 2.3.9, it would be hard to see 

massive production in the 2021 because of many potential issues. The agencies expect a small 

market penetration with one percent in 2021. Based on the industrial trend for typical 

complicated system like WHR, it would take time to have a sizeable market penetration, and 

therefore, it is estimated that 5 percent in 2024, and 15 percent in 2027. Except downsizing, all 

other technologies, such as parasitic/friction loss, aftertreatment, air breathing system, and 

combustion use the same assumption on the market penetration, such as 45 percent in 2021, 95

percent in 2024, and 100 percent in 2027. With respect to engine downsizing, the agencies don’t 

expect high market penetration as others, because downsizing always has the trade-off with 

reliability and resale values. However, we do see the potential that this type of technology can 

be effective when combining with down speeding, specifically when power demand drops due to 

more efficient engine and vehicle. It is a matter of choices. We assume 10 percent, 20 percent, 

and 30 percent market penetration in 2021, 2024, and 2027 respectively. 

It should be pointed out that the technology road maps shown in Table 2-8 including both 

reduction and market penetration would be only one of many paths manufacturers might adopt in 

order to achieve 1.5 percent, 3.7, and 4.2 percent reduction goals in 2021, 2024 and 2027 

respectively. In addition, use of 1 percent, 5 percent, and 15 percent market penetration on WHR 

in 2021, 2024, and 2027 is one of many potential paths. Considering relatively small assumed 

market penetration, this only translates into very small percent improvements due to WHR. The 

manufacturers should be able to make up the difference or achieve the same reduction goals for 

2021, 2024 and 2027 by either increasing individual technology improvement factors or 

increasing market penetration or combination of both. 

Table 2-8 Projected Tractor Engine Technologies and Reduction, Percent Improvements Beyond Phase 1, 

2017 Engine as Baseline

SET MODE SET 

WEIGHTED 

REDUCTION 

(%) 2020-2027

MARKET 

PENETRATION

(2021)

MARKET 

PENETRATION 

(2024)

MARKET 

PENETRATION 

(2027)

Turbo compound with clutch 1.8% 5% 10% 10%

WHR (Rankine cycle) 3.6% 1% 5% 15%

Parasitic/Friction (Cyl Kits, 

pumps, FIE), lubrication

1.4% 45% 95% 100%

Aftertreatment (lower dP) 0.6% 45% 95% 100%

EGR/Intake & exhaust 

manifolds/Turbo /VVT/Ports

1.1% 45% 95% 100%

Combustion/FI/Control 1.1% 45% 95% 100%

Downsizing 0.3% 10% 20% 30%

Weighted reduction (%) 1.5% 3.7% 4.2%

For the vocational engines, the agencies considered the same technology package 

developed for the HHD diesel engines as for the LHD diesel and MHD diesel engines. Similar 

to tractor engines, the package includes parasitic and friction reduction, improved lubrication, 

aftertreatment improvements, EGR system and air flow improvements, and combustion 

improvement. However, WHR technology is not part of the package. The reason is that WHR is 
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not as efficient in transient mode, and since this is the principal operating mode for vocational 

vehicles, we project limited benefit for using WHR for vocational applications. Table 2-9 below 

lists those potential technologies together with the agencies’ estimated market penetration for 

vocational engines, which is developed by combining the various CBI data with the agencies’ 

engineering judgment. 

The market penetration estimate shown in this table uses the same principle as the one 

discussed in the tractor engine. In terms of effectiveness, the model based control would be one 

of the most effective technologies. However, it would take significant efforts to develop it and 

put into production, such as neural network approach developed by Daimler19,20, because one of 

the issues is that it is still not clear how this type of technology interact with on-board 

diagnostics (OBD). Therefore, we expect 25 percent market penetration in 2021, 30 percent in 

2024, and finally 40 percent in 2027. In contrast, all other technologies, such as 

parasitic/friction, air breathing system, aftertreatment, and combustion are relatively more 

mature than the model based control, and therefore, higher market penetration is assumed. 

Table 2-9 Projected Vocational Engine Technologies and Reduction, Percent Improvements Beyond Phase 1, 

2017 Engine as Baseline

TECHNOLOGY GHG 

EMISSIONS 

REDUCTION 

2020-2027

MARKET 

PENETRATION 

2021

MARKET 

PENETRATION 

2024

MARKET 

PENETRATION 

2027

Model based control 2.0% 25% 30% 40%

Parasitic /Friction 1.5% 60% 90% 100%

EGR/Air/VVT /Turbo 1.0% 50% 90% 100%

Improved AT 0.5% 50% 90% 100%

Combustion Optimization 1.0% 50% 90% 100%

Weighted reduction (%)-

L/M/HHD

2.0% 3.5% 4.0%

2.7.5 2021 Model Year HHD Diesel Engine Package for Tractor 

As can be seen from Table 2-8 the weighted reduction for a MY2021 tractor engine is 1.5 

percent. With this reduction, the numerical stringency values for 2021 can be derived from the 

Phase 1 rules. These proposed standards are shown in Table 2-10. 

Table 2-10 2021 Model Year Proposed Standards – Tractors 

MHDD- SET HHDD -

SET

CO2 Emissions (g CO2/bhp-hr) 479 453

Fuel Consumption (gal/100 bhp-hr) 4.71 4.45

The cost estimates for the complete HHD diesel engine packages can be developed 

accordingly as shown in Table 2-11.
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Table 2-11 Technology Costs as Applied in Expected Packages for MY2021 Tractor Diesel Engines under the 

Preferred Alternative relative to the Less Dynamic Baseline (2012$)a

MEDIUM 

HD

HEAVY 

HD

Aftertreatment system (improved effectiveness SCR, dosing, DPF) $7 $7

Valve Actuation $82 $82

Cylinder Head (flow optimized, increased firing pressure, improved thermal 

management)

$3 $3

Turbocharger (improved efficiency) $9 $9

Turbo Compounding $50 $50

EGR Cooler (improved efficiency) $2 $2

Water Pump (optimized, variable vane, variable speed) $43 $43

Oil Pump (optimized) $2 $2

Fuel Pump (higher working pressure, increased efficiency, improved pressure 

regulation)

$2 $2

Fuel Rail (higher working pressure) $5 $5

Fuel Injector (optimized, improved multiple event control, higher working pressure) $5 $5

Piston (reduced friction skirt, ring and pin) $1 $1

Valve Train (reduced friction, roller tappet) $39 $39

Waste Heat Recovery $105 $105

“Right sized” engine -$40 -$40

Total $314 $314

Note:

a Costs presented here include application rates.

2.7.6 2021 Model Year LHD/MHD/HHD Diesel Engine Package for 

Vocational Vehicles

From Table 2-9, the proposed weighted reduction for 2021 model years of all 

LHD/MHD/HHD vocational diesel engines is 2.0 percent. Table 2-12 lists the numerical 

stringency values in 2021 model year.

Table 2-12 2021 Model Year Proposed Standards -- Vocational

LHDD -

FTP

MHDD -

FTP

HHDD -

FTP

CO2 Emissions (g CO2/bhp-hr) 565 565 544

Fuel Consumption (gal/100 bhp-hr) 5.55 5.55 5.34

The cost estimates for the MY2021 vocational diesel engines are shown in Table 2-13. 

We present technology cost estimates along with adoption rates in Chapter 2.12 of this draft 

RIA. We present package cost estimates in greater detail in Chapter 2.13 of this draft RIA.
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Table 2-13 Technology Costs as Applied in Expected Packages for MY2021 Vocational Diesel Engines under 

the Preferred Alternative relative to the Less Dynamic Baseline (2012$)a

LIGHT 

HD

MEDIUM 

HD

HEAVY 

HD

Aftertreatment system (improved effectiveness SCR, dosing, DPF) $8 $8 $8

Valve Actuation $91 $91 $91

Cylinder Head (flow optimized, increased firing pressure, improved 

thermal management)

$6 $3 $3

Turbocharger (improved efficiency) $10 $10 $10

EGR Cooler (improved efficiency) $2 $2 $2

Water Pump (optimized, variable vane, variable speed) $57 $57 $57

Oil Pump (optimized) $3 $3 $3

Fuel Pump (higher working pressure, increased efficiency, improved 

pressure regulation)

$3 $3 $3

Fuel Rail (higher working pressure) $7 $6 $6

Fuel Injector (optimized, improved multiple event control, higher 

working pressure)

$8 $6 $6

Piston (reduced friction skirt, ring and pin) $1 $1 $1

Valve Train (reduced friction, roller tappet) $69 $52 $52

Model Based Controls $28 $28 $28

Total $293 $270 $270

Note:

a Costs presented here include application rates.

2.7.7 2024 Model Year HHDD Engine Package for Tractor

The agencies assessed the impact of technologies over each of the SET modes to project 

an overall improvement in the 2024 model year. The agencies considered additional 

improvements in the technologies included in the 2021 model year package. Compared to 2021 

technology package, the technology package in 2024 considers higher market adoption as shown

in Table 2-8, thus deriving the stringency at 3.7 percent. Table 2-14 below shows the proposed 

2024 model year tractor engine standards.

Table 2-14 2024 Model Year Proposed Standards – Tractors 

MHDD- SET HHDD - SET

CO2 Emissions (g CO2/bhp-hr) 469 443

Fuel Consumption (gal/100 bhp-hr) 4.61 4.35

The costs for the MY2024 tractor diesel engines are shown in Table 2-15. We present 

technology cost estimates along with adoption rates in Chapter 2.12 of this draft RIA. We 

present package cost estimates in greater detail in Chapter 2.13 of this draft RIA.
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Table 2-15 Technology Costs as Applied in Expected Packages for MY2024 Tractor Diesel Engines under the 

Preferred Alternative relative to the Less Dynamic Baseline (2012$)a

MEDIUM 

HD

HEAVY 

HD

Aftertreatment system (improved effectiveness SCR, dosing, DPF) $14 $14

Valve Actuation $166 $166

Cylinder Head (flow optimized, increased firing pressure, improved thermal 

management)

$6 $6

Turbocharger (improved efficiency) $17 $17

Turbo Compounding $92 $92

EGR Cooler (improved efficiency) $3 $3

Water Pump (optimized, variable vane, variable speed) $84 $84

Oil Pump (optimized) $4 $4

Fuel Pump (higher working pressure, increased efficiency, improved pressure 

regulation)

$4 $4

Fuel Rail (higher working pressure) $9 $9

Fuel Injector (optimized, improved multiple event control, higher working pressure) $10 $10

Piston (reduced friction skirt, ring and pin) $3 $3

Valve Train (reduced friction, roller tappet) $75 $75

Waste Heat Recovery $502 $502

“Right sized” engine -$85 -$85

Total $904 $904

Note:

a Costs presented here include application rates.

2.7.8 2024 Model Year LHD/MHD/HHD Diesel Engine Package for 

Vocational Vehicles

The agencies developed the 2024 model year LHD/MHD/HHD diesel engine package 

based on additional improvements in the technologies included in the 2021 model year package 

as shown in Table 2-9. The projected impact of these technologies provides an overall reduction 

of 3.5 percent over the 2017 model year baseline. Table 2-16 below shows the proposed 2024 

model year standards in numerical values.

Table 2-16 2024 Model Year Proposed Standards – Vocational

LHDD -

FTP

MHDD -

FTP

HHDD -

FTP

CO2 Emissions (g CO2/bhp-hr) 556 556 536

Fuel Consumption (gal/100 bhp-hr) 5.46 5.46 5.26

Costs for MY 2024 vocational diesel engines are shown in Table 2-17. We present 

technology cost estimates along with adoption rates in Chapter 2.12 of this draft RIA. We 

present package cost estimates in greater detail in Chapter 2.13 of this draft RIA.
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Table 2-17 Technology Costs as Applied in Expected Packages for MY2024 Vocational Diesel Engines under 

the Preferred Alternative relative to the Less Dynamic Baseline (2012$)a

LIGHT 

HD

MEDIUM 

HD

HEAVY 

HD

Aftertreatment system (improved effectiveness SCR, dosing, DPF) $13 $13 $13

Valve Actuation $157 $157 $157

Cylinder Head (flow optimized, increased firing pressure, improved 

thermal management)

$10 $6 $6

Turbocharger (improved efficiency) $16 $16 $16

EGR Cooler (improved efficiency) $3 $3 $3

Water Pump (optimized, variable vane, variable speed) $79 $79 $79

Oil Pump (optimized) $4 $4 $4

Fuel Pump (higher working pressure, increased efficiency, improved 

pressure regulation)

$4 $4 $4

Fuel Rail (higher working pressure) $10 $9 $9

Fuel Injector (optimized, improved multiple event control, higher 

working pressure)

$13 $10 $10

Piston (reduced friction skirt, ring and pin) $2 $2 $2

Valve Train (reduced friction, roller tappet) $95 $71 $71

Model Based Controls $31 $31 $31

Total $437 $405 $405

Note:

a Costs presented here include application rates.

2.7.9 2027 Model Year HHDD Engine Package for Tractor

The agencies assessed the impact of technologies over each of the SET modes to project 

an overall improvement in the 2027 model year. The agencies considered additional 

improvements in the technologies included in the 2021 model year package. Compared to 2021 

technology package, the technology package in 2027 considers higher market adoption as shown 

in Table 2-8, thus deriving the stringency at 4.2 percent. Table 2-18 below shows the proposed 

2027 model year tractor engine standards.

Table 2-18 2027 Model Year Proposed Standards – Tractors 

MHDD- SET HHDD - SET

CO2 Emissions (g CO2/bhp-hr) 466 441

Fuel Consumption (gal/100 bhp-hr) 4.58 4.33

The costs for the MY2027 tractor diesel engines are shown in Table 2-19. We present 

technology cost estimates along with adoption rates in Chapter 2.12 of this draft RIA. We 

present package cost estimates in greater detail in Chapter 2.13 of this draft RIA.
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Table 2-19 Technology Costs as Applied in Expected Packages for MY2027 Tractor Diesel Engines under the 

Preferred Alternative relative to the Less Dynamic Baseline (2012$)a

MEDIUM 

HD

HEAVY 

HD

Aftertreatment system (improved effectiveness SCR, dosing, DPF) $14 $14

Valve Actuation $169 $169

Cylinder Head (flow optimized, increased firing pressure, improved thermal 

management)

$6 $6

Turbocharger (improved efficiency) $17 $17

Turbo Compounding $87 $87

EGR Cooler (improved efficiency) $3 $3

Water Pump (optimized, variable vane, variable speed) $84 $84

Oil Pump (optimized) $4 $4

Fuel Pump (higher working pressure, increased efficiency, improved pressure 

regulation)

$4 $4

Fuel Rail (higher working pressure) $9 $9

Fuel Injector (optimized, improved multiple event control, higher working pressure) $10 $10

Piston (reduced friction skirt, ring and pin) $3 $3

Valve Train (reduced friction, roller tappet) $75 $75

Waste Heat Recovery $1,340 $1,340

“Right sized” engine -$127 -$127

Total $1,698 $1,698

Note:

a Costs presented here include application rates.

2.7.10 2027 Model Year LHD/MHD/HHD Diesel Engine Package for 

Vocational Vehicles

The agencies developed the 2027 model year LHD/MHD/HHD diesel engine package 

based on additional improvements in the technologies included in the 2021 model year package 

as shown in Table 2-9. The projected impact of these technologies provides an overall reduction 

of 4.0 percent over the 2017 model year baseline. Table 2-20 below shows the proposed 2027

model year standards in numerical values.

Table 2-20 2027 Model Year Proposed Standards – Vocational

LHDD - FTP MHDD- FTP HHDD - FTP

CO2 Emissions (g CO2/bhp-hr) 553 553 533

Fuel Consumption (gal/100 bhp-hr) 5.43 5.43 5.23

Costs for MY 2027 vocational diesel engines are shown in Table 2-21. We present 

technology cost estimates along with adoption rates in Chapter 2.12 of this draft RIA. We 

present package cost estimates in greater detail in Chapter 2.13 of this draft RIA.
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Table 2-21 Technology Costs as Applied in Expected Packages for MY2027 Vocational Diesel Engines under 

the Preferred Alternative relative to the Less Dynamic Baseline (2012$)a

LIGHT 

HD

MEDIUM 

HD

HEAVY 

HD

Aftertreatment system (improved effectiveness SCR, dosing, DPF) $14 $14 $14

Valve Actuation $169 $169 $169

Cylinder Head (flow optimized, increased firing pressure, improved 

thermal management)

$10 $6 $6

Turbocharger (improved efficiency) $17 $17 $17

EGR Cooler (improved efficiency) $3 $3 $3

Water Pump (optimized, variable vane, variable speed) $84 $84 $84

Oil Pump (optimized) $4 $4 $4

Fuel Pump (higher working pressure, increased efficiency, improved 

pressure regulation)

$4 $4 $4

Fuel Rail (higher working pressure) $11 $9 $9

Fuel Injector (optimized, improved multiple event control, higher 

working pressure)

$13 $10 $10

Piston (reduced friction skirt, ring and pin) $3 $3 $3

Valve Train (reduced friction, roller tappet) $100 $75 $75

Model Based Controls $39 $39 $39

Total $471 $437 $437

Note:

a Costs presented here include application rates.

2.7.11 HD Diesel Engine Packages under the More Stringent Alternative 4

The more stringent alternative 4 would impose new standards in MYs 2021 and 2024, 

with the MY2024 standards essentially equivalent to the MY2027 standards under the preferred 

alternative. The resultant HDD engine costs for both tractors and vocational engines in MYs 

2021 and 2024 are shown in Table 2-22. Note that, while the technology application rates in 

MY2024 under alternative 4 are essentially identical to those for MY2027 under alternative 3, 

the costs are higher under alternative 4 due to learning effects and markup changes that are 

estimated to have occurred by MY2027 under alternative 3.

Table 2-22 Technology Costs as Applied in Expected Packages for HD Diesel Engines under the More 

Stringent Alternative 4 relative to the Less Dynamic Baseline (2012$)a

MODEL 

YEAR

MHDD 

TRACTOR

HHDD 

TRACTOR

LHDD 

VOCATIONAL

MHDD 

VOCATIONAL

HHDD 

VOCATIONAL

2021 $656 $656 $372 $345 $345

2024 $1,885 $1,885 $493 $457 $457

Note:

a Costs presented here include application rates.

2.8 Technology Application and Estimated Costs – Tractors

2.8.1 Defining the Baseline Tractors

The fuel efficiency and CO2 emissions of combination tractors vary depending on the 

configuration of the tractor. Many aspects of the tractor impact its performance, including the 
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engine, transmission, drive axle, aerodynamics, and rolling resistance. For each tractor 

subcategory, the agencies selected a theoretical tractor to represent the average 2017 model year 

tractor that meets the Phase 1 standards (see 76 FR 57212, September 15, 2011). These tractors 

are used as baselines from which to evaluate costs and effectiveness of additional technologies 

and standards. The specific attributes of each tractor subcategory are listed below in Table 2-23. 

Using these values, the agencies assessed the CO2 emissions and fuel consumption performance 

of the proposed baseline tractors using the proposed version of Phase 2 GEM. The results of 

these simulations are shown below in Table 2-24. 

The Phase 1 2017 model year tractor standards and the baseline 2017 model year tractor 

results are not directly comparable. The same set of aerodynamic and tire rolling resistance 

technologies were used in both setting the Phase 1 standards and determining the baseline of the 

Phase 2 tractors. However, there are several aspects that differ. First, a new version of GEM 

was developed and validated to provide additional capabilities, including more refined modeling 

of transmissions and engines. Second, the determination of the proposed HD Phase 2 CdA value 

takes into account a revised test procedure, a new standard reference trailer, and wind averaged 

drag. In addition, the proposed HD Phase 2 version of GEM includes road grade in the 55 mph 

and 65 mph highway cycles, as discussed in preamble Section III.E. Finally, the agencies 

assessed the current level of automatic engine shutdown and idle reduction technologies used by

the tractor manufacturers to comply with the 2014 model year CO2 and fuel consumption 

standards. To date, the manufacturers are meeting the 2014 model year standards without the 

use of this technology. Therefore, the agencies are revising the baseline APU adoption rate back 

to 30 percent, the value used in the Phase 1 baseline.

Table 2-23 GEM Inputs for the Baseline Class 7 and 8 Tractor 

CLASS 7 CLASS 8

Day Cab Day Cab Sleeper Cab

Low 

Roof

Mid 

Roof

High Roof Low Roof Mid 

Roof

High Roof Low Roof Mid 

Roof

High 

Roof

Engine

2017 MY 

11L 

Engine 

350 HP

2017 MY 

11L 

Engine 

350 HP

2017 MY 

11L 

Engine 

350 HP

2017 MY 

15L 

Engine 

455 HP

2017 MY 

15L 

Engine 

455 HP

2017 MY 

15L 

Engine 

455 HP

2017 MY 

15L 

Engine 

455 HP

2017 MY 

15L 

Engine 

455 HP

2017 MY 

15L 

Engine 

455 HP

Aerodynamics (CdA in m2)

5.00 6.40 6.42 5.00 6.40 6.42 4.95 6.35 6.22

Steer Tires (CRR in kg/metric ton)

6.99 6.99 6.87 6.99 6.99 6.87 6.87 6.87 6.54

Drive Tires (CRR in kg/metric ton)

7.38 7.38 7.26 7.38 7.38 7.26 7.26 7.26 6.92

Extended Idle Reduction Adoption Rate

N/A N/A N/A N/A N/A N/A 30% 30% 30%

Transmission = 10 Speed Manual Transmission

Gear Ratios = 12.8, 9.25, 6.76, 4.90, 3.58, 2.61, 1.89, 1.38, 1.00, 0.73

Drive Axle Ratio = 3.70
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Table 2-24 Class 7 and 8 Tractor Baseline CO2 Emissions and Fuel Consumption

CLASS 7 CLASS 8

Day Cab Day Cab Sleeper Cab

Low 

Roof

Mid 

Roof

High 

Roof

Low 

Roof

Mid 

Roof

High 

Roof

Low 

Roof

Mid 

Roof

High 

Roof

CO2 (grams 

CO2/ton-mile)

107 118 121 86 93 95 79 87 88

Fuel 

Consumption 

(gal/1,000 tonmile)

10.5 11.6 11.9 8.4 9.1 9.3 7.8 8.5 8.6

The 2017 model year baseline fuel maps in the HD Phase 2 version of GEM are different 

than those used in 2017 year fuel maps in the HD Phase 1 version. The baseline map in the HD 

Phase 2 version takes two major factors into consideration. The first is the likelihood of engine 

down speeding beyond the 2020 model year and the second is to make the gradient of brake 

specific fuel consumption rate (BSFC) around the fuel consumption sweet spot less radical when 

compared to the HD Phase 1 version’s engine fuel map. 

Figure 2-11 gives an example of an engine fuel map for a 455hp rated engine.

183

183

183

183

184

184

184

184

184

186

186

186

186

186

190

190

190

190

190

193

193

193

193

19

19

3

6

196

196

196

203

203

203

203

203

218

218

218

218

239 239

239

183

455 HP / 15 L : 2018 Baseline BSFC (g/kW-hr)

Engine Speed (RPM)

T

orq

u

e (N

m)

600 800 1000 1200 1400 1600 1800 2000

0

200

400

600

800

1000

1200

1400

1600

1800

2000

2200

Figure 2-11 2018MY 15L Engine Fuel Map
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2.8.2 Defining the Proposed Tractor Technology Packages

The agencies’ assessment of the proposed technology effectiveness was developed 

through the use of GEM in coordination with modeling conducted by Southwest Research 

Institute. The agencies developed the proposed standards through a three-step process, similar to 

the approach used in Phase 1. First, the agencies developed technology performance 

characteristics for each technology, as described below. Each technology is associated with an 

input parameter which in turn would be used as an input to the Phase 2 GEM simulation tool and 

its effectiveness thereby modeled. Second, the agencies combined the technology performance 

levels with a projected technology adoption rate to determine the GEM inputs used to set the 

stringency of the proposed standards. Third, the agencies input these parameters into Phase 2 

GEM and used the output to determine the proposed CO2 emissions and fuel consumption levels. 

All percentage improvements noted below are over the 2017 baseline tractor.

2.8.2.1 Aerodynamics

The aerodynamic packages are categorized as Bin I, Bin II, Bin III, Bin IV, Bin V, Bin 

VI, or Bin VII based on the wind averaged drag aerodynamic performance determined through 

testing conducted by the manufacturer. In general, the proposed CdA values for each package 

and tractor subcategory were developed through EPA’s coastdown testing of tractor-trailer 

combinations, the 2010 NAS report, and SAE papers. 

2.8.2.2 Tire Rolling Resistance

The proposed rolling resistance coefficient target for Phase 2 was developed from 

SmartWay’s tire testing to develop the SmartWay verification, testing a selection of tractor tires 

as part of the Phase 1 and Phase 2 programs, and from 2014 MY certification data. Even though 

the coefficient of tire rolling resistance comes in a range of values, to analyze this range, the tire 

performance was evaluated at four levels determined by the agencies. The four levels are the 

baseline (average) from 2010, Level I and Level 2 from Phase 1, and Level 3 that achieves an 

additional 25 percent improvement over Level 2. The Level 1 rolling resistance performance 

represents the threshold used to develop SmartWay designated tires for long haul tractors. The 

Level 2 threshold represents an incremental step for improvements beyond today’s SmartWay

level and represents the best in class rolling resistance of the tires we tested. The Level 3 values 

represent the long-term rolling resistance value that Michelin predicts could be achieved in the 

2025 timeframe. 111 The tire rolling resistance level assumed to meet the 2017 MY Phase 1 

standard high roof sleeper cab is considered to be a weighted average of 10 percent baseline 

rolling resistance, 70 percent Level 1, and 20 percent Level 2. The tire rolling resistance to meet 

the 2017MY Phase 1 standards for the high roof day cab, low roof sleeper cab, and mid roof 

sleeper cab includes 30 percent baseline, 60 percent Level 1 and 10 percent Level 2. Finally, the 

low roof day cab 2017MY standard can be met with a weighted average rolling resistance 

consisting of 40 percent baseline, 50 percent Level 1, and 10 percent Level 2.
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2.8.2.3 Idle Reduction

The benefits for the extended idle reductions were developed from literature, SmartWay

work, and the 2010 NAS report. Additional details regarding the comments and calculations are 

included in RIA Section 2.4.

2.8.2.4 Transmission

The benefits for automated manual, automatic, and dual clutch transmissions were 

developed from literature and from simulation modeling conducted by Southwest Research 

Institute. The benefit of these transmissions is proposed to be set to a two percent improvement 

over a manual transmission due to the automation of the gear shifting.

2.8.2.5 Drivetrain

The reduction in friction due to low viscosity axle lubricants is set to 0.5 percent. 6x4 

and 4x2 axle configurations lead to a 2.5 percent improvement in vehicle efficiency. 

Downspeeding would be as demonstrated through the Phase 2 GEM inputs of transmission gear 

ratio, drive axle ratio, and tire diameter. Downspeeding is projected to improve the fuel 

consumption by 1.8 percent.

2.8.2.6 Accessories and Other Technologies

Compared to 2017MY air conditioners, air conditioners with improved efficiency

compressors could reduce CO2 emissions by 0.5 percent. Improvements in accessories, such as 

power steering, can lead to an efficiency improvement of 1 percent over the 2017MY baseline. 

Based on literature information, intelligent controls such as predictive cruise control could

reduce CO2 emissions by two percent while automatic tire inflation systems improve fuel 

consumption by one percent by keeping tire rolling resistance to its optimum based on inflation 

pressure.

2.8.2.7 Weight Reduction

The weight reductions were developed from tire manufacturer information, the 

Aluminum Association, the Department of Energy, SABIC and TIAX. 

2.8.2.8 Vehicle Speed Limiter

The agencies did not include vehicle speed limiters in setting the Phase 1 stringency

levels. The agencies are not including vehicle speed limiters in the technology package for 

setting the proposed standards for Class 7 and 8 tractors.

2.8.2.9 Summary of Technology Performance

Table 2-25 describes the performance levels for the range of Class 7 and 8 tractor vehicle 

technologies. 
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Table 2-25 Proposed Phase 2 Technology Inputs

CLASS 7 CLASS 8

Day Cab Day Cab Sleeper Cab

Low 

Roof

Mid 

Roof

High 

Roof

Low 

Roof

Mid 

Roof

High 

Roof

Low 

Roof

Mid 

Roof

High 

Roof

Engine

2021M

Y 11L 

Engine 

350 HP

2021M

Y 11L 

Engine 

350 HP

2021M

Y 11L 

Engine 

350 HP

2021M

Y 15L 

Engine 

455 HP

2021M

Y 15L 

Engine 

455 HP

2021M

Y 15L 

Engine 

455 HP

2021MY 

15L 

Engine 

455 HP

2021M

Y 15L 

Engine 

455 HP

2021MY 

15L 

Engine 

455 HP

Aerodynamics (CdA in m2)

Bin I 5.3 6.7 7.6 5.3 6.7 7.6 5.3 6.7 7.4

Bin II 4.8 6.2 7.1 4.8 6.2 7.1 4.8 6.2 6.9

Bin III 4.3 5.7 6.5 4.3 5.7 6.5 4.3 5.7 6.3

Bin IV 4.0 5.4 5.8 4.0 5.4 5.8 4.0 5.4 5.6

Bin V 5.3 5.3 5.1

Bin VI 4.9 4.9 4.7

Bin VII 4.5 4.5 4.3

Steer Tires (CRR in kg/metric ton)

Base 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8

Level 1 6.6 6.6 6.6 6.6 6.6 6.6 6.6 6.6 6.6

Level 2 5.7 5.7 5.7 5.7 5.7 5.7 5.7 5.7 5.7

Level 3 4.3 4.3 4.3 4.3 4.3 4.3 4.3 4.3 4.3

Drive Tires (CRR in kg/metric ton)

Base 8.2 8.2 8.2 8.2 8.2 8.2 8.2 8.2 8.2

Level 1 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0

Level 2 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0

Level 3 4.5 4.5 4.5 4.5 4.5 4.5 4.5 4.5 4.5

Idle Reduction (% reduction)

APU N/A N/A N/A N/A N/A N/A 5% 5% 5%

Other N/A N/A N/A N/A N/A N/A 7% 7% 7%

Transmission Type (% reduction)

Manual 0% 0% 0% 0% 0% 0% 0% 0% 0%

AMT 2% 2% 2% 2% 2% 2% 2% 2% 2%

Auto 2% 2% 2% 2% 2% 2% 2% 2% 2%

Dual Clutch 2% 2% 2% 2% 2% 2% 2% 2% 2%

Driveline (% reduction)

Axle 

Lubricant

0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5%

6x2 or 4x2 

Axle

2.5% 2.5% 2.5% 2.5% 2.5% 2.5% 2.5% 2.5% 2.5%

Downspeed 1.8% 1.8% 1.8% 1.8% 1.8% 1.8% 1.8% 1.8% 1.8%

Accessory Improvements (% reduction)

A/C 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5%

Electric or 

Mech. 

Access.

1% 1% 1% 1% 1% 1% 1% 1% 1%
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Off-Cycle Technologies (% reduction)

Predictive 

Cruise 

Control

2% 2% 2% 2% 2% 2% 2% 2% 2%

Automated 

Tire 

Inflation 

System

1% 1% 1% 1% 1% 1% 1% 1% 1%

2.8.3 Tractor Technology Adoption Rates

As explained above, tractor manufacturers often introduce major product changes 

together, as a package. In this manner the manufacturers can optimize their available resources, 

including engineering, development, manufacturing and marketing activities to create a product 

with multiple new features. In addition, manufacturers recognize that a vehicle design will need 

to remain competitive over the intended life of the design and meet future regulatory

requirements. In some limited cases, manufacturers may implement an individual technology

outside of a vehicle’s redesign cycle. 

With respect to the levels of technology adoption used to develop the proposed HD Phase 

2 standards, NHTSA and EPA established technology adoption constraints. The first type of 

constraint was established based on the application of fuel consumption and CO2 emission 

reduction technologies into the different types of tractors. For example, extended idle reduction 

technologies are limited to Class 8 sleeper cabs using the assumption that day cabs are not used 

for overnight hoteling. A second type of constraint was applied to most other technologies and 

limited their adoption based on factors reflecting the real world operating conditions that some 

combination tractors encounter. This second type of constraint was applied to the aerodynamic, 

tire, powertrain, and vehicle speed limiter technologies. Table 2-26, Table 2-27 and Table 2-28

specify the adoption rates that EPA and NHTSA used to develop the proposed standards. 

NHTSA and EPA believe that within each of these individual vehicle categories there are 

particular applications where the use of the identified technologies would be either ineffective or 

not technically feasible. The addition of ineffective technologies provides no environmental or 

fuel efficiency benefit, increases costs and is not a basis upon which to set a maximum feasible 

improvement under 49 USC Section 32902 (k), or appropriate under 42 U.S.C. Section 7521 

(a)(2). For example, the agencies are not predicating the proposed standards on the use of full 

aerodynamic vehicle treatments on 100 percent of tractors, because we know that in many

applications (for example gravel truck engaged in local aggregate delivery) the added weight of 

the aerodynamic technologies would increase fuel consumption and hence CO2 emissions to a 

greater degree than the reduction that would be accomplished from the more aerodynamic nature 

of the tractor. 

2.8.3.1 Aerodynamics Adoption Rate

The impact of aerodynamics on a tractor-trailer’s efficiency increases with vehicle speed. 

Therefore, the usage pattern of the vehicle will determine the benefit of various aerodynamic 

technologies. Sleeper cabs are often used in line haul applications and drive the majority of their 
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miles on the highway travelling at speeds greater than 55 mph. The industry has focused 

aerodynamic technology development, including SmartWay tractors, on these types of trucks. 

Therefore the agencies are proposing the most aggressive aerodynamic technology application to 

this regulatory subcategory. All of the major manufacturers today offer at least one SmartWay

sleeper cab tractor model, which is represented as Bin III aerodynamic performance. The 

proposed aerodynamic adoption rate for Class 8 high roof sleeper cabs in 2024 (i.e., the degree 

of technology adoption on which the stringency of the proposed standard is premised) consists of 

30 percent of Bin IV, 25 percent Bin V, 13 percent Bin VI, and 2 percent Bin VII reflecting our 

assessment of the fraction of tractors in this segment that could successfully apply these 

aerodynamic packages. We believe that there is sufficient lead time to develop aerodynamic 

tractors that can move the entire high roof sleeper cab aerodynamic performance to be as good as 

or better than today’s SmartWay designated tractors. The changes required for Bin IV and better 

performance reflect the kinds of improvements projected in the Department of Energy’s 

SuperTruck program. That program assumes that such systems can be demonstrated on vehicles 

by 2017. In this case, the agencies are projecting that truck OEMs would be able to begin 

implementing these aerodynamic technologies as early as 2021 MY on a limited scale. 

Importantly, our averaging, banking and trading provisions provide manufacturers with the 

flexibility to implement these technologies over time even though the standard changes in a 

single step. 

The aerodynamic adoption rates used to develop the proposed standards for the other 

tractor regulatory categories are less aggressive than for the Class 8 sleeper cab high roof. 

Aerodynamic improvements through new tractor designs and the development of new 

aerodynamic components is an inherently slow and iterative process. The agencies recognize 

that there are tractor applications which require on/off-road capability and other truck functions 

which restrict the type of aerodynamic equipment applicable. We also recognize that these types 

of trucks spend less time at highway speeds where aerodynamic technologies have the greatest 

benefit. The 2002 VIUS data ranks trucks by major use.112 The heavy trucks usage indicates 

that up to 35 percent of the trucks may be used in on/off-road applications or heavier 

applications. The uses include construction (16 percent), agriculture (12 percent), waste 

management (5 percent), and mining (2 percent). Therefore, the agencies analyzed the 

technologies to evaluate the potential restrictions that would prevent 100 percent adoption of 

more advanced aerodynamic technologies for all of the tractor regulatory subcategories.

2.8.3.2 Low Rolling Resistance Tire Adoption Rate

For the tire manufacturers to further reduce tire rolling resistance, the manufacturers must 

consider several performance criteria that affect tire selection. The characteristics of a tire also 

influence durability, traction control, vehicle handling, comfort, and retreadability. A single 

performance parameter can easily be enhanced, but an optimal balance of all the criteria would

require improvements in materials and tread design at a higher cost, as estimated by the agencies. 

Tire design requires balancing performance, since changes in design may change different 

performance characteristics in opposing directions. Similar to the discussion regarding lesser 

aerodynamic technology application in tractor segments other than sleeper cab high roof, the 

agencies believe that the proposed standards should not be premised on 100 percent application 

of Level IV tires in all tractor segments given the potential interference with vehicle utility that 

could result. 
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2.8.3.3 Weight Reduction Technology Adoption Rate

The agencies propose setting the 2021 through 2027 model year tractor standards without 

using weight reduction as a technology to demonstrate the feasibility. The agencies view weight 

reduction as a technology with a high cost that offers a small benefit in the tractor sector. For 

example, our estimate of a 400 pound weight reduction would cost $2,050 (2012$) in MY2021, 

but offer a 0.3 percent reduction in fuel consumption and CO2 emissions.

2.8.3.4 Idle Reduction Technology Adoption Rate

Idle reduction technologies provide significant reductions in fuel consumption and CO2

emissions for Class 8 sleeper cabs and are available on the market today. There are several 

different technologies available to reduce idling. These include APUs, diesel fired heaters, and 

battery powered units. Our discussions with manufacturers indicate that idle technologies are 

sometimes installed in the factory, but it is also a common practice to have the units installed 

after the sale of the truck. We would like to continue to incentivize this practice and to do so in a 

manner that the emission reductions associated with idle reduction technology occur in use. 

Therefore, as adopted in Phase 1, we are allowing only idle emission reduction technologies 

which include an automatic engine shutdown (AES) with some override provisions. In the 

preamble in Section III, we request comment on other approaches that would appropriately 

quantify the reductions that would be experienced in the real world. 

We propose a 90 percent adoption rate for this technology for Class 8 sleeper cabs. The 

agencies are unaware of reasons why AES with extended idle reduction technologies could not 

be applied to this high fraction of tractors with a sleeper cab, except those deemed a vocational 

tractor, in the available lead time. 

The agencies are interested in extending the idle reduction benefits beyond Class 8 

sleepers, including day cabs. The agencies reviewed literature to quantify the amount of idling 

which is conducted outside of hoteling operations. One study, conducted by Argonne National 

Laboratory, identified several different types of trucks which might idle for extended amounts of 

time during the work day.113 Idling may occur during the delivery process, queuing at loading 

docks or border crossings, during power take off operations, or to provide comfort during the 

work day. However, the study provided only “rough estimates” of the idle time and energy use 

for these vehicles. The agencies are not able to appropriately develop a baseline of workday

idling for day cabs and identify the percent of this idling which could be reduced through the use 

of AES. 

2.8.3.5 Vehicle Speed Limiter Adoption Rate

As adopted in Phase 1, we propose to continue the approach where vehicle speed limiters 

may be used as a technology to meet the proposed standard. In setting the proposed standard, 

however, we assumed a zero percent adoption rate of vehicle speed limiters. Although we 

believe vehicle speed limiters are a simple, easy to implement, and inexpensive technology, we 

want to leave the use of vehicles speed limiters to the truck purchaser. Since truck fleets 

purchase tractors today with owner-set vehicle speed limiters, we considered not including VSLs 

in our compliance model. However, we have concluded that we should allow the use of VSLs 
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that cannot be overridden by the operator as a means of compliance for vehicle manufacturers 

that wish to offer it and truck purchasers that wish to purchase the technology. In doing so, we 

are providing another means of meeting that standard that can lower compliance cost and provide 

a more optimal vehicle solution for some truck fleets. For example, a local beverage distributor 

may operate trucks in a distribution network of primarily local roads. Under those conditions, 

aerodynamic fairings used to reduce aerodynamic drag provide little benefit due to the low 

vehicle speed while adding additional mass to the vehicle. A vehicle manufacturer could choose 

to install a VSL set at 55 mph for this customer. The resulting tractor would be optimized for its 

intended application and would be fully compliant with our program all at a lower cost to the 

ultimate tractor purchaser.J 

As in Phase 1, we have chosen not to base the proposed standards on performance of 

VSLs because of concerns about how to set a realistic adoption rate that avoids unintended 

adverse impacts. Although we expect there will be some use of VSL, currently it is used when 

the fleet involved decides it is feasible and practicable and increases the overall efficiency of the 

freight system for that fleet operator. To date, the compliance data provided by manufacturers 

indicate that none of the tractor configurations include a tamper-proof VSL setting less than 65 

mph. At this point the agencies are not in a position to determine in how many additional 

situations use of a VSL would result in similar benefits to overall efficiency or how many 

customers would be willing to accept a tamper-proof VSL setting. We are not able at this time to 

quantify the potential loss in utility due to the use of VSLs. Absent this information, we cannot 

make a determination regarding the reasonableness of setting a standard based on a particular 

VSL level. Therefore, the agencies are not premising the proposed standards on use of VSL, and 

instead would continue to rely on the industry to select VSL when circumstances are appropriate 

for its use. The agencies have not included either the cost or benefit due to VSLs in analysis of 

the proposed program’s costs and benefits. 

2.8.3.6 Summary of the Adoption Rates used to Determine the Proposed Standards

Table 2-26, Table 2-27, and Table 2-28 provide the adoption rates of each technology

broken down by weight class, cab configuration, and roof height.

Table 2-26 Technology Adoption Rates for Class 7 and 8 Tractors for Determining the Proposed 2021 MY 

Standards

CLASS 7 CLASS 8

Day Cab Day Cab Sleeper Cab

Low 

Roof

Mid 

Roof

High 

Roof

Low 

Roof

Mid 

Roof

High 

Roof

Low 

Roof

Mid 

Roof

High 

Roof

2021 MY Engine Technology Package

100% 100% 100% 100% 100% 100% 100% 100% 100%

Aerodynamics 

Bin I 0% 0% 0% 0% 0% 0% 0% 0% 0%

 

J The agencies note that because a VSL value can be input into GEM, its benefits can be directly assessed with the 

model and off cycle credit applications therefore are not necessary even though the proposed standard is not based 

on performance of VSLs (i.e. VSL is an on-cycle technology).
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Bin II 75% 75% 0% 75% 75% 0% 75% 75% 0%

Bin III 25% 25% 40% 25% 25% 40% 25% 25% 40%

Bin IV 0% 0% 35% 0% 0% 35% 0% 0% 35%

Bin V 20% 20% 20%

Bin VI 5% 5% 5%

Bin VII 0% 0% 0%

Steer Tires 

Base 5% 5% 5% 5% 5% 5% 5% 5% 5%

Level 1 60% 60% 60% 60% 60% 60% 60% 60% 60%

Level 2 25% 25% 25% 25% 25% 25% 25% 25% 25%

Level 3 10% 10% 10% 10% 10% 10% 10% 10% 10%

Drive Tires 

Base 5% 5% 5% 5% 5% 5% 5% 5% 5%

Level 1 60% 60% 60% 60% 60% 60% 60% 60% 60%

Level 2 25% 25% 25% 25% 25% 25% 25% 25% 25%

Level 3 10% 10% 10% 10% 10% 10% 10% 10% 10%

Extended Idle Reduction 

APU N/A N/A N/A N/A N/A N/A 80% 80% 80%

Transmission Type 

Manual 45% 45% 45% 45% 45% 45% 45% 45% 45%

AMT 40% 40% 40% 40% 40% 40% 40% 40% 40%

Auto 10% 10% 10% 10% 10% 10% 10% 10% 10%

Dual Clutch 5% 5% 5% 5% 5% 5% 5% 5% 5%

Driveline 

Axle 

Lubricant

20% 20% 20% 20% 20% 20% 20% 20% 20%

6x2 or 4x2 

Axle

10% 10% 20% 10% 10% 20%

Downspeed 20% 20% 20% 20% 20% 20% 20% 20% 20%

Accessory Improvements 

A/C 10% 10% 10% 10% 10% 10% 10% 10% 10%

Electric 

Access.

10% 10% 10% 10% 10% 10% 10% 10% 10%

Off-Cycle Technologies 

Predictive 

Cruise 

Control

20% 20% 20% 20% 20% 20% 20% 20% 20%

Automated 

Tire 

Inflation 

System

20% 20% 20% 20% 20% 20% 20% 20% 20%
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-27 Technology Adoption Rates for Class 7 and 8 Tractors for Determining the Proposed 2024 MY 

Standards

CLASS 7 CLASS 8

Day Cab Day Cab Sleeper Cab

Low 

Roof

Mid 

Roof

High 

Roof

Low 

Roof

Mid 

Roof

High 

Roof

Low 

Roof

Mid 

Roof

High 

Roof

2024MY Engine Technology Package

100% 100% 100% 100% 100% 100% 100% 100% 100%

Aerodynamics 

Bin I 0% 0% 0% 0% 0% 0% 0% 0% 0%

Bin II 60% 60% 0% 60% 60% 0% 60% 60% 0%

Bin III 38% 38% 30% 38% 38% 30% 38% 38% 30%

Bin IV 2% 2% 30% 2% 2% 30% 2% 2% 30%

Bin V 25% 25% 25%

Bin VI 13% 13% 13%

Bin VII 2% 2% 2%

Steer Tires 

Base 5% 5% 5% 5% 5% 5% 5% 5% 5%

Level 1 50% 50% 50% 50% 50% 50% 50% 50% 50%

Level 2 30% 30% 30% 30% 30% 30% 30% 30% 30%

Level 3 15% 15% 15% 15% 15% 15% 15% 15% 15%

Drive Tires 

Base 5% 5% 5% 5% 5% 5% 5% 5% 5%

Level 1 50% 50% 50% 50% 50% 50% 50% 50% 50%

Level 2 30% 30% 30% 30% 30% 30% 30% 30% 30%

Level 3 15% 15% 15% 15% 15% 15% 15% 15% 15%

Extended Idle Reduction 

APU N/A N/A N/A N/A N/A N/A 90% 90% 90%

Transmission Type 

Manual 20% 20% 20% 20% 20% 20% 20% 20% 20%

AMT 50% 50% 50% 50% 50% 50% 50% 50% 50%

Auto 20% 20% 20% 20% 20% 20% 20% 20% 20%

Dual Clutch 10% 10% 10% 10% 10% 10% 10% 10% 10%

Driveline 

Axle 

Lubricant

40% 40% 40% 40% 40% 40% 40% 40% 40%

6x2 or 4x2 

Axle

20% 20% 60% 20% 20% 60%

Downspeed 40% 40% 40% 40% 40% 40% 40% 40% 40%

Direct Drive 50% 50% 50% 50% 50% 50% 50% 50% 50%

Accessory Improvements 

A/C 20% 20% 20% 20% 20% 20% 20% 20% 20%

Electric 

Access.

20% 20% 20% 20% 20% 20% 20% 20% 20%

Other Technologies 

Predictive 

Cruise 

40% 40% 40% 40% 40% 40% 40% 40% 40%
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Control

Automated 

Tire 

Inflation 

System

40% 40% 40% 40% 40% 40% 40% 40% 40%
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-28 Technology Adoption Rates for Class 7 and 8 Tractors for Determining the Proposed 2027 MY 

Standards

CLASS 7 CLASS 8

Day Cab Day Cab Sleeper Cab

Low 

Roof

Mid 

Roof

High 

Roof

Low 

Roof

Mid 

Roof

High 

Roof

Low 

Roof

Mid 

Roof

High 

Roof

2027 MY Engine Technology Package

100% 100% 100% 100% 100% 100% 100% 100% 100%

Aerodynamics 

Bin I 0% 0% 0% 0% 0% 0% 0% 0% 0%

Bin II 50% 50% 0% 50% 50% 0% 50% 50% 0%

Bin III 40% 40% 20% 40% 40% 20% 40% 40% 20%

Bin IV 10% 10% 20% 10% 10% 20% 10% 10% 20%

Bin V 35% 35% 35%

Bin VI 20% 20% 20%

Bin VII 5% 5% 5%

Steer Tires 

Base 5% 5% 5% 5% 5% 5% 5% 5% 5%

Level 1 20% 20% 20% 20% 20% 20% 20% 20% 20%

Level 2 50% 50% 50% 50% 50% 50% 50% 50% 50%

Level 3 25% 25% 25% 25% 25% 25% 25% 25% 25%

Drive Tires 

Base 5% 5% 5% 5% 5% 5% 5% 5% 5%

Level 1 20% 20% 20% 20% 20% 20% 20% 20% 20%

Level 2 50% 50% 50% 50% 50% 50% 50% 50% 50%

Level 3 25% 25% 25% 25% 25% 25% 25% 25% 25%

Extended Idle Reduction 

APU N/A N/A N/A N/A N/A N/A 90% 90% 90%

Transmission Type 

Manual 10% 10% 10% 10% 10% 10% 10% 10% 10%

AMT 50% 50% 50% 50% 50% 50% 50% 50% 50%

Auto 30% 30% 30% 30% 30% 30% 30% 30% 30%

Dual Clutch 10% 10% 10% 10% 10% 10% 10% 10% 10%

Driveline 

Axle 

Lubricant

40% 40% 40% 40% 40% 40% 40% 40% 40%

6x2 Axle 20% 20% 60% 20% 20% 60%

Downspeed 60% 60% 60% 60% 60% 60% 60% 60% 60%

Direct Drive 50% 50% 50% 50% 50% 50% 50% 50% 50%

Accessory Improvements 

A/C 30% 30% 30% 30% 30% 30% 30% 30% 30%

Electric 

Access.

30% 30% 30% 30% 30% 30% 30% 30% 30%

Other Technologies 

Predictive 

Cruise 

Control

40% 40% 40% 40% 40% 40% 40% 40% 40%

Automated 40% 40% 40% 40% 40% 40% 40% 40% 40%
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

2-94

Tire 

Inflation 

System

2.8.4 Derivation of the Proposed Tractor Standards

The agencies used the technology effectiveness inputs and technology adoption rates to 

develop GEM inputs to derive the proposed HD Phase 2 fuel consumption and CO2 emissions 

standards for each subcategory of Class 7 and 8 combination tractors. Note that we have 

analyzed one technology pathway for each proposed level of stringency as required by the Clean 

Air Act, but manufacturers would be free to use any combination of technology to meet the 

standards on average. As such, the agencies derived a scenario tractor for each subcategory by

weighting the individual GEM input parameters included in Table 2-25 with the adoption rates in 

Table 2-26, Table 2-27, and Table 2-28. For example, the proposed CdA value for a 2021MY 

Class 8 Sleeper Cab High Roof scenario case was derived as 40 percent times 6.3 plus 35 percent 

times 5.6 plus 20 percent times 5.1 plus 5 percent times 4.7, which is equal to a CdA of 5.74 m2. 

Similar calculations were made for tire rolling resistance, transmission types, idle reduction, and 

other technologies. To account for the proposed engine standards and engine technologies, the 

agencies assumed a compliant engine fuel map in GEM, as described in the section below.

K

 The 

agencies then ran GEM with a single set of vehicle inputs, as shown in Table 2-30, to derive the 

proposed standards for each subcategory. 

2.8.4.1 2021 through 2027 MY Engine Fuel Maps

One of the most significant changes in the HD Phase 2 version of GEM is the allowance 

for manufacturers to enter their own engine fuel maps by following the test procedure described 

in the Chapter 3 Test Procedure section of this draft RIA. The GEM engine fuel map input file 

consists of three types of information in csv format. The first set of information contains the 

engine fueling map and includes three columns: engine speed in rpm, engine torque in Nm, and 

engine fueling rate in g/s. In the second set of information contains the engine full torque or lug 

curve in two columns: engine speed in rpm and torque in NM. The third set of information 

contains the motoring torque and uses the same format and units as the full load torque curve. 

The agencies developed default engine fuel maps for all subcategories, utilizing the same 

format that the manufacturers would be required to provide. Fuel maps were developed for the 

2021, 2024, and 2027 model years by applying the technologies assumed in deriving the 

proposed engine standards to the 2018 baseline engine fuel maps. Those default maps are 

derived from multiple sources of confidential business information from different stakeholders 

together with engineering judgment. These maps cover a total of 18 vehicles subcategories 

including nine tractor subcategories. We would like to point out that some of the subcategories 

share the same engine fuel maps. A list of all of the engine fuel maps used in setting the 

 

K

See draft RIA Chapter 2.7 explaining the derivation of the proposed engine standards.
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2-95

standards for each subcategory is given in Table 2-29. The model years covered by the maps are 

2021, 2024, and 2027 and are shown in Figure 2-12, Figure 2-13, and Figure 2-14. 

Table 2-29 GEM Default CI Engine Fuel Maps for Tractor Vehicles

REGULATORY SUBCATEGORY ENGINE FUEL MAP

Class 8 Combination Sleeper Cab - High Roof 15L - 455 HP

Class 8 Combination Sleeper Cab - Mid Roof 15L - 455 HP

Class 8 Combination Sleeper Cab - Low Roof 15L - 455 HP

Class 8 Combination Day Cab - High Roof 15L - 455 HP

Class 8 Combination Day Cab - Mid Roof 15L - 455 HP

Class 8 Combination Day Cab - Low Roof 15L - 455 HP

Class 7 Combination Day Cab - High Roof 11L - 350 HP

Class 7 Combination Day Cab - Mid Roof 11L - 350 HP

Class 7 Combination Day Cab - Low Roof 11L - 350 HP

Figure 2-12 455 HP Engine fuel map used in HD Phase 2 version of GEM to Set 2021MY Standards
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Figure 2-13 455 HP Engine fuel map used in HD Phase 2 version of GEM to Set 2024MY Standards
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Figure 2-14 455 HP Engine fuel map used in HD Phase 2 version of GEM to Set 2027MY Standard
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-30 GEM Inputs for the Proposed 2021MY Class 7 and 8 Tractor Standard Setting

CLASS 7 CLASS 8

Day Cab Day Cab Sleeper Cab

Low 

Roof

Mid 

Roof

High 

Roof

Low 

Roof

Mid 

Roof

High 

Roof

Low 

Roof

Mid 

Roof

High 

Roof

Engine

2021MY 

11L 

Engine 

350 HP

2021MY 

11L 

Engine 

350 HP

2021MY 

11L 

Engine 

350 HP

2021MY 

15L 

Engine 

455 HP

2021MY 

15L 

Engine 

455 HP

2021MY 

15L 

Engine 

455 HP

2021MY 

15L 

Engine 

455 HP

2021MY 

15L 

Engine 

455 HP

2021MY 

15L 

Engine 

455 HP

Aerodynamics (CdA in m2)

4.68 6.08 5.94 4.68 6.08 5.94 4.68 6.08 5.74

Steer Tires (CRR in kg/metric ton)

6.2 6.2 6.2 6.2 6.2 6.2 6.2 6.2 6.2

Drive Tires (CRR in kg/metric ton)

6.6 6.6 6.6 6.6 6.6 6.6 6.6 6.6 6.6

Extended Idle Reduction Weighted Effectiveness

N/A N/A N/A N/A N/A N/A 2.5% 2.5% 2.5%

Transmission = 10 speed Automated Manual Transmission

Gear Ratios = 12.8, 9.25, 6.76, 4.90, 3.58, 2.61, 1.89, 1.38, 1.00, 0.73

Drive axle Ratio = 3.55

6x2 Axle Disconnect Weighted Effectiveness

N/A N/A N/A 0.3% 0.3% 0.5% 0.3% 0.3% 0.5%

Low Friction Axle Lubrication = 0.1%

Transmission benefit = 1.1%

Predictive Cruise Control =0.4%

Accessory Improvements = 0.1%

Air Conditioner Efficiency Improvements = 0.1%

Automatic Tire Inflation Systems = 0.2%

Weight Reduction = 0 pounds
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-31 GEM Inputs for the Proposed 2024MY Class 7 and 8 Tractor Standard Setting

CLASS 7 CLASS 8

Day Cab Day Cab Sleeper Cab

Low 

Roof

Mid 

Roof

High 

Roof

Low 

Roof

Mid 

Roof

High 

Roof

Low 

Roof

Mid 

Roof

High 

Roof

Engine

2024MY 

11L 

Engine 

350 HP

2024MY 

11L 

Engine 

350 HP

2024MY 

11L 

Engine 

350 HP

2024MY 

15L 

Engine 

455 HP

2024MY 

15L 

Engine 

455 HP

2024MY 

15L 

Engine 

455 HP

2024MY 

15L 

Engine 

455 HP

2024MY 

15L 

Engine 

455 HP

2024MY 

15L 

Engine 

455 HP

Aerodynamics (CdA in m2)

4.59 5.99 5.74 4.59 5.99 5.74 4.59 5.99 5.54

Steer Tires (CRR in kg/metric ton)

5.9 5.9 5.9 5.9 5.9 5.9 5.9 5.9 5.9

Drive Tires (CRR in kg/metric ton)

6.2 6.2 6.2 6.2 6.2 6.2 6.2 6.2 6.2

Extended Idle Reduction Adoption Rate

N/A N/A N/A N/A N/A N/A 3% 3% 3%

Transmission = 10 speed Automated Manual Transmission

Gear Ratios = 12.8, 9.25, 6.76, 4.90, 3.58, 2.61, 1.89, 1.38, 1.00, 0.73

Drive axle Ratio = 3.36

6x2 Axle Disconnect Weighted Effectiveness

N/A N/A N/A 0.5% 0.5% 1.5% 0.5% 0.5% 1.5%

Low Friction Axle Lubrication = 0.2%

Transmission benefit = 1.8%

Predictive Cruise Control =0.8%

Accessory Improvements = 0.2%

Air Conditioner Efficiency Improvements = 0.1%

Automatic Tire Inflation Systems = 0.4%

Weight Reduction = 0 pounds

Direct Drive Weighted Efficiency = 1% for sleeper cabs; 0.8% for day cabs
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-32 GEM Inputs for the Proposed 2027MY Class 7 and 8 Tractor Standard Setting

CLASS 7 CLASS 8

Day Cab Day Cab Sleeper Cab

Low 

Roof

Mid 

Roof

High Roof Low Roof Mid 

Roof

High Roof Low Roof Mid 

Roof

High 

Roof

Engine

2027MY 

11L 

Engine 

350 HP

2027MY 

11L 

Engine 

350 HP

2027MY 

11L 

Engine 

350 HP

2027MY 

15L 

Engine 

455 HP

2027MY 

15L 

Engine 

455 HP

2027MY 

15L 

Engine 

455 HP

2027MY 

15L 

Engine 

455 HP

2027MY 

15L 

Engine 

455 HP

2027MY 

15L 

Engine 

455 HP

Aerodynamics (CdA in m2)

4.52 5.92 5.52 4.52 5.92 5.52 4.52 5.92 5.32

Steer Tires (CRR in kg/metric ton)

5.6 5.6 5.6 5.6 5.6 5.6 5.6 5.6 5.6

Drive Tires (CRR in kg/metric ton)

5.9 5.9 5.9 5.9 5.9 5.9 5.9 5.9 5.9

Extended Idle Reduction Weighted Effectiveness

N/A N/A N/A N/A N/A N/A 3% 3% 3%

Transmission = 10 speed Automated Manual Transmission

Gear Ratios = 12.8, 9.25, 6.76, 4.90, 3.58, 2.61, 1.89, 1.38, 1.00, 0.73

Drive axle Ratio = 3.2

6x2 Axle Disconnect Weighted Effectiveness

N/A N/A N/A 0.5% 0.5% 1.5% 0.5% 0.5% 1.5%

Low Friction Axle Lubrication = 0.2%

Transmission benefit = 1.8%

Predictive Cruise Control =0.8%

Accessory Improvements = 0.3%

Air Conditioner Efficiency Improvements = 0.2%

Automatic Tire Inflation Systems = 0.4%

Weight Reduction = 0 pounds

Direct Drive Weighted Efficiency = 1% for sleeper cabs; 0.8% for day cabs

The level of the 2021, 2024, and 2027 model year proposed standards for each 

subcategory are included in Table 2-33.
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-33 Proposed 2021, 2024, and 2027 Model Year Tractor Standards

2021 MODEL YEAR CO2 GRAMS PER TON-MILE

Day Cab Sleeper Cab

Class 7 Class 8 Class 8

Low Roof 97 78 70

Mid Roof 107 84 78

High Roof 109 86 77

2021 Model Year Gallons of Fuel per 1,000 Ton-Mile

Day Cab Sleeper Cab

Class 7 Class 8 Class 8

Low Roof 9.5285 7.5639 6.8762

Mid Roof 10.5108 8.2515 7.6621

High Roof 10.7073 8.4479 7.5639

2024 Model Year CO2 Grams per Ton-Mile

Day Cab Sleeper Cab

Class 7 Class 8 Class 8

Low Roof 90 72 64

Mid Roof 100 78 71

High Roof 101 79 70

2024 Model Year and Later Gallons of Fuel per 1,000 Ton-Mile

Day Cab Sleeper Cab

Class 7 Class 8 Class 8

Low Roof 8.8409 7.0727 6.2868

Mid Roof 9.8232 7.5639 6.9745

High Roof 9.9214 7.7603 6.8762

2027 Model Year CO2 Grams per Ton-Mile

Day Cab Sleeper Cab

Class 7 Class 8 Class 8

Low Roof 87 70 62

Mid Roof 96 76 69

High Roof 96 76 67

2027 Model Year and Later Gallons of Fuel per 1,000 Ton-Mile

Day Cab Sleeper Cab

Class 7 Class 8 Class 8

Low Roof 8.5462 6.8762 6.0904

Mid Roof 9.4303 7.4656 6.7780

High Roof 9.4303 7.4656 6.5815

2.8.4.2 Heavy-Haul Tractor Standards

For Phase 2, the agencies propose to add a tenth subcategory to the tractor category for 

heavy-haul tractors. The agencies recognize the need for manufacturers to build these types of 
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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vehicles for specific applications and believe the appropriate way to prevent penalizing these 

vehicles is to set separate standards recognizing a heavy-haul vehicle’s unique needs, such as 

requiring a higher horsepower engine or different transmissions. The agencies are proposing this 

change in Phase 2 because unlike in Phase 1 the engine, transmission, and drivetrain 

technologies are included in the technology packages used to determine the stringency of the 

proposed tractor standards and are included as manufacturer inputs in GEM. 

The agencies recognize that certain technologies used to determine the stringency of the 

proposed Phase 2 tractor standards are less applicable to heavy-haul tractors. Heavy-haul 

tractors are not typically used in the same manner as long-haul tractors with extended highway

driving, therefore would experience less benefit from aerodynamics. Aerodynamic technologies 

are very effective at reducing the fuel consumption and GHG emissions of tractors, but only

when traveling at highway speeds. At lower speeds, the aerodynamic technologies may have a

detrimental impact due to the potential of added weight. The agencies therefore are not 

considering the use of aerodynamic technologies in the development of the proposed Phase 2 

heavy-haul tractor standards. Moreover, because aerodynamics would not play a role in the 

heavy-haul standards, the agencies propose to combine all of the heavy-haul tractor cab 

configurations (day and sleeper) and roof heights (low, mid, and high) into a single heavy-haul 

tractor subcategory.

L

 

Certain powertrain and drivetrain components are also impacted during the design of a 

heavy-haul tractor, including the transmission, axles, and the engine. Heavy-haul tractors 

typically require transmissions with 13 or 18 speeds to provide the ratio spread to ensure that the 

tractor is able to start pulling the load from a stop. Downsped powertrains are typically not an 

option for heavy-haul operations because these vehicles require more torque to move the vehicle 

because of the heavier load. Finally, due to the loading requirements of the vehicle, it is not 

likely that a 6x2 axle configuration can be used in heavy-haul applications.

The agencies used the following heavy-haul tractor inputs for developing the proposed 

2021, 2024, and 2027 MY standards, as shown in Table 2-34. 

 

L

Since aerodynamic improvements are not part of the technology package, the agencies likewise are not proposing 

any bin structure for the heavy-haul tractor subcategory.
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-34 GEM Inputs for Proposed 2021, 2024 and 2027 MY Heavy-Haul Tractor Standards

HEAVY-HAUL TRACTOR

Baseline 2021MY 2024MY 2027MY

Engine = 2017 MY 15L 

Engine with 600 HP

Engine = 2021 MY 15L 

Engine with 600 HP

Engine = 2024 MY 15L 

Engine with 600 HP

Engine = 2027 MY 15L 

Engine with 600 HP

Aerodynamics (CdA in m2) = 5.00

Steer Tires (CRR in 

kg/metric ton) = 7.0

Steer Tires (CRR in 

kg/metric ton) = 6.2

Steer Tires (CRR in 

kg/metric ton) = 6.0

Steer Tires (CRR in 

kg/metric ton) = 5.8

Drive Tires (CRR in 

kg/metric ton) = 7.4

Drive Tires (CRR in 

kg/metric ton) = 6.6

Drive Tires (CRR in 

kg/metric ton) = 6.4

Drive Tires (CRR in 

kg/metric ton) = 6.2

Transmission = 13 speed 

Manual Transmission

Gear Ratios = 12.29, 

8.51, 6.05, 4.38, 3.20, 

2.29, 1.95, 1.62, 1.38, 

1.17, 1.00, 0.86, 0.73

Transmission = 13 speed 

Automated Manual 

Transmission

Gear Ratios = 12.29, 8.51, 

6.05, 4.38, 3.20, 2.29, 1.95, 

1.62, 1.38, 1.17, 1.00, 0.86, 

0.73

Transmission = 13 speed 

Automated Manual 

Transmission

Gear Ratios = 12.29, 8.51, 

6.05, 4.38, 3.20, 2.29, 1.95, 

1.62, 1.38, 1.17, 1.00, 0.86, 

0.73

Transmission = 13 speed 

Automated Manual 

Transmission

Gear Ratios = 12.29, 8.51, 

6.05, 4.38, 3.20, 2.29, 1.95, 

1.62, 1.38, 1.17, 1.00, 0.86, 

0.73

Drive axle Ratio = 3.55 Drive axle Ratio = 3.55 Drive axle Ratio = 3.55 Drive axle Ratio = 3.55

6x2 Axle Disconnect 

Weighted Effectiveness = 0%

6x2 Axle Disconnect 

Weighted Effectiveness = 

0%

6x2 Axle Disconnect 

Weighted Effectiveness = 0%

Low Friction Axle 

Lubrication = 0.1%

Low Friction Axle 

Lubrication = 0.2%

Low Friction Axle 

Lubrication = 0.2%

AMT benefit = 1.1% AMT benefit = 1.8% AMT benefit = 1.8%

Predictive Cruise Control 

=0.4%

Predictive Cruise Control 

=0.8%

Predictive Cruise Control 

=0.8%

Accessory Improvements = 

0.1%

Accessory Improvements = 

0.2%

Accessory Improvements = 

0.3%

Air Conditioner Efficiency

Improvements = 0.1%

Air Conditioner Efficiency 

Improvements = 0.1%

Air Conditioner Efficiency 

Improvements = 0.2%

Automatic Tire Inflation 

Systems = 0.2%

Automatic Tire Inflation 

Systems = 0.4%

Automatic Tire Inflation 

Systems = 0.4%

Weight Reduction = 0 

pounds

Weight Reduction = 0 

pounds

Weight Reduction = 0 

pounds

The baseline 2017 MY heavy-haul tractor would emit 57 grams of CO2 per ton-mile and 

consume 5.6 gallons of fuel per 1,000 ton-mile. The agencies propose the heavy-haul standards 

shown in Table 2-35. 

Table 2-35 Proposed Heavy-Haul Tractor Standards

HEAVY-HAUL TRACTOR

2021 MY 2024 MY 2027 MY

Grams of CO2 per 

Ton-Mile Standard

54 52 51

Gallons of Fuel per 

1,000 Ton-Mile

5.3045 5.1081 5.010
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2.8.4.3 Tractor Package Costs under the Preferred and Alternative Standards

A summary of the draft technology package costs under the preferred alternative and 

relative to the less dynamic baseline is included in Table 2-36 through Table 2-39 for MYs 2021, 

2024, and 2027, respectively. A summary of the draft technology package costs under 

alternative 4 and relative to the less dynamic baseline is included in Table 2-40 and Table 2-41

for MYs 2021 and 2024, respectively.

Table 2-36 Class 7 and 8 Tractor Technology Incremental Costs in the 2021 Model Yeara,b

Preferred Alternative vs. the Less Dynamic Baseline (2012$ per vehicle)

CLASS 7 CLASS 8

Day Cab Day Cab Sleeper Cab

Low/Mid 

Roof

High 

Roof

Low/ Mid 

Roof

High 

Roof

Low 

Roof

Mid 

Roof

High 

Roof

Enginec $314 $314 $314 $314 $314 $314 $314

Aerodynamics $687 $511 $687 $511 $656 $656 $535

Tires $49 $9 $81 $15 $59 $59 $15

Tire inflation 

system

$180 $180 $180 $180 $180 $180 $180

Transmission $3,969 $3,969 $3,969 $3,969 $3,969 $3,969 $3,969

Axle & axle 

lubes

$50 $50 $70 $90 $70 $70 $90

Idle reduction 

with APU

$0 $0 $0 $0 $2,449 $2,449 $2,449

Air 

conditioning

$45 $45 $45 $45 $45 $45 $45

Other vehicle 

technologies

$174 $174 $174 $174 $174 $174 $174

Total $5,468 $5,252 $5,520 $5,298 $7,916 $7,916 $7,771

Notes:

a Costs shown are for the 2021 model year and are incremental to the costs of a tractor meeting the phase 1 

standards. These costs include indirect costs via markups along with learning impacts. For a description of the 

markups and learning impacts considered in this analysis and how it impacts technology costs for other years, refer 

to Chapter 2 of the draft RIA (see draft RIA 2.12).

b Note that values in this table include adoption rates. Therefore, the technology costs shown reflect the average cost 

expected for each of the indicated tractor classes. To see the actual estimated technology costs exclusive of adoption

rates, refer to Chapter 2 of the draft RIA (see draft RIA 2.12 in particular).

c Engine costs are for a heavy HD diesel engine meant for a combination tractor.
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Table 2-37 Class 7 and 8 Tractor Technology Incremental Costs in the 2024 Model Yeara,b

Preferred Alternative vs. the Less Dynamic Baseline (2012$ per vehicle)

CLASS 7 CLASS 8

Day Cab Day Cab Sleeper Cab

Low/Mid 

Roof

High 

Roof

Low/ Mid 

Roof

High 

Roof

Low 

Roof

Mid 

Roof

High 

Roof

Enginec $904 $904 $904 $904 $904 $904 $904

Aerodynamics $744 $684 $744 $684 $712 $712 $723

Tires $47 $11 $78 $18 $58 $58 $18

Tire inflation 

system

$330 $330 $330 $330 $330 $330 $330

Transmission $5,883 $5,883 $5,883 $5,883 $5,883 $5,883 $5,883

Axle & axle 

lubes

$92 $92 $128 $200 $128 $128 $200

Idle reduction 

with APU

$0 $0 $0 $0 $2,687 $2,687 $2,687

Air 

conditioning

$82 $82 $82 $82 $82 $82 $82

Other vehicle 

technologies

$318 $318 $318 $318 $318 $318 $318

Total $8,400 $8,304 $8,467 $8,419 $11,102 $11,102 $11,145

Notes:

a Costs shown are for the 2021 model year and are incremental to the costs of a tractor meeting the phase 1 

standards. These costs include indirect costs via markups along with learning impacts. For a description of the 

markups and learning impacts considered in this analysis and how it impacts technology costs for other years, refer 

to Chapter 2 of the draft RIA (see draft RIA 2.12).

b Note that values in this table include adoption rates. Therefore, the technology costs shown reflect the average cost 

expected for each of the indicated tractor classes. To see the actual estimated technology costs exclusive of adoption

rates, refer to Chapter 2 of the draft RIA (see draft RIA 2.12).

c Engine costs are for a heavy HD diesel engine meant for a combination tractor.
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Table 2-38 Class 7 and 8 Tractor Technology Incremental Costs in the 2027 Model Yeara,b

Preferred Alternative vs. the Less Dynamic Baseline (2012$ per vehicle)

CLASS 7 CLASS 8

Day Cab Day Cab Sleeper Cab

Low/Mid 

Roof

High 

Roof

Low/ Mid 

Roof

High 

Roof

Low 

Roof

Mid 

Roof

High 

Roof

Enginec $1,698 $1,698 $1,698 $1,698 $1,698 $1,698 $1,698

Aerodynamics $771 $765 $771 $765 $733 $733 $802

Tires $45 $10 $75 $17 $56 $56 $17

Tire inflation 

system

$314 $314 $314 $314 $314 $314 $314

Transmission $6,797 $6,797 $6,797 $6,797 $6,797 $6,797 $6,797

Axle & axle 

lubes

$97 $97 $131 $200 $131 $131 $200

Idle reduction 

with APU

$0 $0 $0 $0 $2,596 $2,596 $2,596

Air 

conditioning

$117 $117 $117 $117 $117 $117 $117

Other vehicle 

technologies

$302 $302 $302 $302 $302 $302 $302

Total $10,140 $10,099 $10,204 $10,209 $12,744 $12,744 $12,842

Notes:

a Costs shown are for the 2021 model year and are incremental to the costs of a tractor meeting the phase 1 

standards. These costs include indirect costs via markups along with learning impacts. For a description of the 

markups and learning impacts considered in this analysis and how it impacts technology costs for other years, refer 

to Chapter 2 of the draft RIA (see draft RIA 2.12).

b Note that values in this table include adoption rates. Therefore, the technology costs shown reflect the average cost 

expected for each of the indicated tractor classes. To see the actual estimated technology costs exclusive of adoption

rates, refer to Chapter 2 of the draft RIA (see draft RIA 2.12 in particular).

c Engine costs are for a heavy HD diesel engine meant for a combination tractor.
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Table 2-39 Heavy-Haul Tractor Technology Incremental Costs in the 2021, 2024, and 2027 Model Yeara,b

Preferred Alternative vs. the Less Dynamic Baseline (2012$ per vehicle)

2021 MY 2024 MY 2027 MY

Enginec $314 $904 $1,698

Tires $81 $78 $75

Tire inflation system $180 $330 $314

Transmission $3,969 $5,883 $6,797

Axle & axle lubes $70 $128 $200

Air conditioning $45 $82 $117

Other vehicle technologies $174 $318 $302

Total $4,833 $7,723 $9,503

Notes:

a Costs shown are for the specified model year and are incremental to the costs of a 

tractor meeting the phase 1 standards. These costs include indirect costs via 

markups along with learning impacts. For a description of the markups and 

learning impacts considered in this analysis and how it impacts technology costs 

for other years, refer to Chapter 2 of the draft RIA (see draft RIA 2.12).

b Note that values in this table include adoption rates. Therefore, the technology 

costs shown reflect the average cost expected for each of the indicated tractor 

classes. To see the actual estimated technology costs exclusive of adoption rates, 

refer to Chapter 2 of the draft RIA (see draft RIA 2.12 in particular).

c Engine costs are for a heavy HD diesel engine meant for a combination tractor.
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Table 2-40 Class 7 and 8 Tractor Technology Incremental Costs in the 2021 Model Yeara,b

Alternative 4 vs. the Less Dynamic Baseline (2012$ per vehicle)

CLASS 7 CLASS 8

Day Cab Day Cab Sleeper Cab

Low/Mid 

Roof

High 

Roof

Low/ Mid 

Roof

High 

Roof

Low 

Roof

Mid 

Roof

High 

Roof

Enginec $656 $656 $656 $656 $656 $656 $656

Aerodynamics $769 $632 $769 $632 $740 $740 $665

Tires $50 $11 $83 $18 $61 $61 $18

Tire inflation 

system

$271 $271 $271 $271 $271 $271 $271

Transmission $6,794 $6,794 $6,794 $6,794 $6,794 $6,794 $6,794

Axle & axle 

lubes

$56 $56 $75 $95 $75 $75 $115

Idle reduction 

with APU

$0 $0 $0 $0 $2,449 $2,449 $2,449

Air 

conditioning

$90 $90 $90 $90 $90 $90 $90

Other vehicle 

technologies

$261 $261 $261 $261 $261 $261 $261

Total $8,946 $8,769 $8,999 $8,816 $11,397 $11,397 $11,318

Notes:

a Costs shown are for the 2021 model year and are incremental to the costs of a tractor meeting the phase 1 

standards. These costs include indirect costs via markups along with learning impacts. For a description of the 

markups and learning impacts considered in this analysis and how it impacts technology costs for other years, refer 

to Chapter 2 of the draft RIA (see draft RIA 2.12).

b Note that values in this table include adoption rates. Therefore, the technology costs shown reflect the average cost 

expected for each of the indicated tractor classes. To see the actual estimated technology costs exclusive of adoption

rates, refer to Chapter 2 of the draft RIA (see draft RIA 2.12 in particular).

c Engine costs are for a heavy HD diesel engine meant for a combination tractor.
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Table 2-41 Class 7 and 8 Tractor Technology Incremental Costs in the 2024 Model Yeara,b

Alternative 4 vs. the Less Dynamic Baseline (2012$ per vehicle)

CLASS 7 CLASS 8

Day Cab Day Cab Sleeper Cab

Low/Mid 

Roof

High 

Roof

Low/ Mid 

Roof

High 

Roof

Low 

Roof

Mid 

Roof

High 

Roof

Enginec $1,885 $1,885 $1,885 $1,885 $1,885 $1,885 $1,885

Aerodynamics $805 $935 $805 $935 $773 $773 $997

Tires $50 $14 $83 $23 $63 $63 $23

Tire inflation 

system

$330 $330 $330 $330 $330 $330 $330

Transmission $7,143 $7,143 $7,143 $7,143 $7,143 $7,143 $7,143

Axle & axle 

lubes

$102 $102 $138 $210 $138 $138 $210

Idle reduction 

with APU

$0 $0 $0 $0 $2,687 $2,687 $2,687

Air 

conditioning

$123 $123 $123 $123 $123 $123 $123

Other vehicle 

technologies

$318 $318 $318 $318 $318 $318 $318

Total $10,757 $10,851 $10,826 $10,968 $13,461 $13,461 $13,717

Notes:

a Costs shown are for the 2024 model year and are incremental to the costs of a tractor meeting the Phase 1 

standards. These costs include indirect costs via markups along with learning impacts. For a description of the 

markups and learning impacts considered in this analysis and how it impacts technology costs for other years, refer 

to Chapter 2 of the draft RIA (see draft RIA 2.12).

b Note that values in this table include adoption rates. Therefore, the technology costs shown reflect the average cost 

expected for each of the indicated tractor classes. To see the actual estimated technology costs exclusive of adoption

rates, refer to Chapter 2 of the draft RIA (see draft RIA 2.12 in particular).

c Engine costs are for a heavy HD diesel engine meant for a combination tractor.

2.9 Technology Application and Estimated Costs – Vocational Vehicles

The agencies are analyzing nine baseline vocational vehicle configurations: one for each 

of the nine proposed subcategories obtained with three weight class groups and the three 

proposed composite duty cycles. For each configuration, some of the attributes and parameters 

are proposed to be fixed by the agencies and would not be available as manufacturer inputs, 

while some are proposed to be available to manufacturers when identifying configurations to 

certify in the model years of the proposed HD Phase 2 program. 

2.9.1 Vocational Engines

This section describes the engines the agencies selected to incorporate into the baseline 

vehicle configurations for the nine proposed subcategories of vocational vehicles, and how we

used the GEM tool to establish performance levels of these baseline vehicles. The agencies have 
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developed models for engines that represent performance of the technologies we expect would 

be installed in vocational vehicles in the baseline year of 2017. A description of the technologies 

applied to our 2017 diesel engine models can be found above in Chapter 2.7 of this draft RIA. A 

description of the GEM engine simulation can be found in draft RIA Chapter 4.

2.9.1.1 Baseline Vocational Engines

One of the most significant changes in the HD Phase 2 version of GEM is the provision 

for manufacturers to enter their own engine fuel maps by following the test procedure described 

in the draft RIA Chapter 3. The GEM engine fuel map input file consists of three types of input. 

The first is the engine fueling map and includes: engine speed in rpm, engine torque in Nm, and 

engine fueling rate in g/s. Second is the engine full torque or lug curve by engine speed in rpm 

and torque in NM. The third is the motoring torque curve. 

The agencies have developed the proposed vehicle standards using engine fuel maps 

derived as discussed above in Chapter 2.7for all sub-categories, utilizing the same format that the 

OEMs would be required to provide. Four sets of diesel engine maps cover all nine vocational 

vehicle regulatory categories, as listed in Table 2-42. This means that some of the subcategories 

share the same engine fuel map. For example, all MHD vehicles use the same 7L engine with 

270 hp rating. 

The 15L engine was selected for the Regional HHD subcategory because these vocational 

vehicles often require a similar level of power as a day cab tractor. This is the same power and 

displacement of the engine simulated for HHD vocational vehicles in Phase 1, and is the engine 

powering the Kenworth T700 reference vehicle, as described in RIA Chapter 4 and summarized 

in Table 4-2. An 11L-345 hp engine was selected for the HHD Multi-purpose and Urban 

subcategories, and is the engine powering the New Flyer refuse truck as the applicable reference 

vehicle, as described in RIA Chapter 4. For these two subcategories, the agencies selected this 

engine because this is a more typical power rating for vehicles that are not long haul. For 

example, Volvo manufactures many vehicles that would likely be certified in these 

subcategories, and one product brochure describes an 11L engine as being fitted in all their 

TerraPro refuse trucks and other weight-sensitive applications.114 Although the displacement 

and horsepower rating of this engine are similar to those of the MHD engine described above in 

Chapter 2.8 for Class 7 tractors, the HHD vocational engine described here is very different from 

that MHD tractor engine, both in terms of technology and its engine certification cycle. The 

engine displacements and power ratings for the MHD and LHD vocational subcategories are the 

same as those simulated in GEM for Phase 1. The specifications for the Kenworth T270 truck 

and F650 tow truck that serve as reference vehicles for all MHD and LHD are shown in Table 4-

2 of draft RIA Chapter 4.
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Table 2-42 GEM CI Engines for Vocational Vehicles

REGULATORY SUBCATEGORY AND DUTY CYCLE ENGINE FUEL MAP

Heavy Heavy-Duty (Class 8) Regional Duty Cycle 15L - 455 HP

Heavy Heavy-Duty (Class 8) Multi-Purpose and Urban Duty Cycles 11L - 345 HP

Medium Heavy-Duty (Class 6-7) Regional, Multi-Purpose, and Urban 

Duty Cycles

7L - 270 HP

Light Heavy-Duty (Class 2b-5) Regional, Multi-Purpose, and Urban 

Duty Cycles

7L - 200 HP

The 2017 baseline maps in the HD Phase 2 version of GEM are different than those used 

for simulating engines that would meet the MY2017 vehicle standards in the HD Phase 1 

rulemaking. The baseline map in the HD Phase 2 version takes two major factors into 

consideration. The first is the likelihood of engine down speeding beyond the 2020 model year 

and the second is to make the gradient of brake specific fuel consumption rate (BSFC) around 

the fuel consumption sweet spot less radical when compared to the HD Phase 1 version’s engine 

fuel map. Figure 2-15 gives an example of an engine fuel map for a 455 hp rated CI engine, for 

the baseline year.

183

183

183

183

184

184

184

184

184

186

186

186

186

186

190

190

190

190

190

193

193

193

193

19

19

3

6

196

196

196

203

203

203

203

203

218

218

218

218

239 239

239

183

455 HP / 15 L : 2018 Baseline BSFC (g/kW-hr)

Engine Speed (RPM)

T

orq

u

e (N

m)

600 800 1000 1200 1400 1600 1800 2000

0

200

400

600

800

1000

1200

1400

1600

1800

2000

2200

Figure 2-15 Engine fuel map for 455hp rated CI engine used in HHD Phase 2 Baseline

The agencies do not have baseline fuel maps for SI engines intended for vocational 

vehicles. We have not obtained sufficient manufacturer data to construct a valid set of inputs 

that would reasonably represent a gasoline engine that will comply with the applicable MY 2016 

engine standard. In lieu of a SI engine map, we have approximated the performance of a 
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baseline gasoline engine over the vocational vehicle GEM duty cycles by applying a correction 

factor to the results of simulating identical vocational vehicles fitted with CI engines. This 

correction factor is derived using coefficients from the MY 2018 HD pickup and van Phase 1 

standards for HD gasoline pickup trucks. It is appropriate to do this, because the difference in 

performance of chassis-certified SI complete vehicles and similarly-sized CI complete vehicles 

would likely be proportional to the difference between SI-powered and CI-powered GEMcertified vocational vehicles. Using the HD pickup and van stringency curves and coefficients 

for the MY 2018 targets from Phase 1, the ratio of CO2 performance of gasoline powered 

vehicles to diesel powered vehicles calculates to 1.058. This was derived using the equations 

and coefficients found at 40 CFR 1037.104(a)(2), where a work factor of 9,000 was assumed, 

and the resulting calculated target value for SI vehicles was divided by the similarly calculated 

target value for CI vehicles. The correction factor approach is not the agencies’ preferred 

approach to establishing SI vocational vehicle baseline performance, as it has many drawbacks. 

One key drawback with this approach is that it does not account for the fact that SI engines 

operate very differently than CI engines at idle. Our current model includes information on CI

engine idle performance, and assumes transmissions and torque converters appropriate for CI 

engines. We expect these driveline parameters would be very different for SI powered vehicles, 

which would affect performance over all the GEM duty cycles.

2.9.1.2 Improved Vocational Engines for Phase 2 Standard-Setting

Four model year versions of these engine maps have been developed for each of these 

four diesel engines: one set for MY 2017 as the baseline, a set of maps for MY2021, a set for 

MY2024, and a set for MY 2027, as improved over the 2017 baseline engine maps.

Because the agencies are proposing to retain the Phase 1 SI separate engine standard for 

all implementation years of Phase 2, we developed the proposed Phase 2 standards for vocational 

vehicles powered by SI engines using the same analysis described above for development of the 

SI baseline engine, without further improvement. When developing improvement levels for the 

stringency of the MY 2027 proposed vehicle standards (and the MY 2024 Alternative 4 

standards), the agencies analyzed adoption rates, effectiveness, and cost of SI engine 

technologies that reduce friction. Consistent with our projection of adoption rates of advanced 

engine friction reduction on HD gasoline pickup trucks, the agencies projected that about 40 

percent of SI engines intended for vocational vehicles would already have technologies applied 

that achieve performance equivalent to Level 2 engine friction reduction, making the available 

population that could upgrade to Level 2 about 60 percent for MY 2027. In terms of 

effectiveness, the agencies relied on the data presented in the Joint Technical Support Document 

(TSD) published in support of the LD GHG final rulemaking.115 In Chapter 3 of that document, 

the agencies present effectiveness values for upgrading from baseline levels of engine friction 

reduction to Level 2 (EFR2) as ranging from 3.4 percent to 4.8 percent, for a range of LD vehicle 

types, and with large trucks falling in the middle of this range. The TSD describes example 

technologies as including low-tension piston rings, piston skirt design, roller cam followers, 

improved crankshaft design and bearings, material coatings, material substitution, more optimal 

thermal management, and piston and cylinder surface treatments. For this Phase 2 HD 

rulemaking, the agencies derived incremental EFR2 effectiveness values from the combined 

EFR1+EFR2 values that were relative to baseline-level friction reduction. We were able to do 

this because the TSD also presented incremental improvements for upgrading from EFR1 to 
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EFR2 as ranging from 0.83 to 1.37. The agencies then calculated a mid-range effectiveness 

value representing large trucks of about one percent. In terms of costs, the agencies have 

presented the costs of upgrading from EFR1 to EFR2, as shown in Chapter 2.12 below.

Specifically, the tables in Chapter 2.12.2.17 present the incremental and total costs over the 

model years of the proposed Phase 2 standards for low friction lubricants and engine friction 

reduction. By applying our market adoption rate of approximately 60 percent to the incremental 

costs of upgrading to EFR2 from EFR1, we estimate a vocational vehicle package cost of 

approximately $70 for this technology.

2.9.2 Defining the Baseline Vocational Vehicles

Nine baseline vocational vehicle configurations have been developed. Vocational vehicle 

attributes that would be set by the agencies not only in the baseline but also in the executable 

version of the GEM include: transmission gear efficiencies, transmission inertia, engine inertia, 

axle efficiency, number of axles, axle inertia, axle efficiency, electrical and mechanical 

accessory power demand, vehicle mass and payload, and aerodynamic cross-section and drag 

coefficient. Other vehicle attributes that would be available as user inputs for compliance 

purposes and for which we have established baseline values include: engine power and 

displacement (and multi-point fuel map), axle ratio, transmission type and gear ratios, and tire 

loaded radius. 

In each of these proposed baseline configurations, the agencies have not applied any

vehicle-level fuel saving or emission reduction technology beyond what is required to meet the 

Phase 1 standards. NHTSA and EPA reviewed available information regarding the likelihood 

that manufacturers of vocational vehicles would apply technology beyond what is required for 

Phase 1, and we concluded that the best approach was to analyze a reference case that maintains 

technology performance at the Phase 1 level. Thus, the nine GEM-simulated baseline vocational 

vehicle configurations as well as the programmatic vocational vehicle reference case analyzed in 

this proposal represent what is referred to as a nominally flat baseline. 

Tables 4-8, 4-9, and 4-10 in the draft RIA Chapter 4 present the non-user-adjustable 

modeling parameters for HHD, MHD and LHD vocational vehicles, respectively. In addition to 

those parameters, to completely define the proposed baseline vehicles, the agencies also selected 

parameters shown in Table 2-43, Table 2-44, and Table 2-45.

These attributes and parameters were selected to represent a range of performance across 

this diverse segment, and are intended to represent a reasonable range of vocational chassis 

configurations likely to be manufactured in the implementation years of the Phase 2 program. 

The tire radii and axle ratios were selected based on market research of publically available 

manufacturer product specifications, as well as some confidential manufacturer information 

about configurations sold in prior model years. The transmission gear ratios were selected based 

on the transmissions for which models have been validated in GEM. Using the reference 

vehicles noted above, the agencies were able to better determine an appropriate type of 

transmission and its gear ratios, for all vocational vehicles. Tire radii and axle ratios were 

selected using good engineering judgment and stakeholder input, to reflect reasonable final drive 

ratios to match with our modeled transmissions. In general, the trend is that vehicles with higher 
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final drive ratios have been selected for the subcategories with less weighting of the highway test 

cycles.

The proposed Phase 2 weighting of steer tire CRR and drive tire CRR is different than in 

Phase 1. In Phase 1, the agencies weighted drive and steer tire CRR values as if 50 percent of 

the vehicle load was on the front axle and 50 percent on the rear axle(s). The agencies reviewed 

the Vehicle Valuation Services quick reference guide to obtain typical axle load ratings for a 

variety of vocational vehicle types.116 According to that guide, the examples of vocational 

vehicles with two axles had a rear axle designed to carry between 1.8 and three times the weight 

of the front axle. Examples of vehicles with three axles had combined weights of the rear axles 

designed to carry loads ranging from 2.4 to 3.7 times the weight rating of the front axle. Based 

on this, the agencies propose a Phase 2 weighting of 0.3 times the steer tire CRR and 0.7 times 

the drive tire CRR, representing a weight distribution of the rear axle(s) carrying 2.3 times the 

weight of the front axle.

The proposed allocation of 50 percent of reduced weight back to payload is described 

below in Section 2.9.3.5.

Table 2-43 Heavy Heavy-Duty User-Enterable Modeling Parameters for Vocational Baseline

GEM INPUT HHD (CLASS 8) HHD (CLASS 8) HHD (CLASS 8)

Regional Duty 

Cycle 

Multi-Purpose 

Duty Cycle

Urban Duty Cycle

Transmission

Number of Forward Gears 10 5 5

Gear Ratio for Each Gear 12.8, 9.25, 6.76, 

4.9, 3.58, 2.61, 

1.89, 1.38, 1, 0.73

4.6957, 2.213, 

1.5291, 1, 0.7643

4.6957, 2.213, 

1.5291, 1, 0.7643

Architecture Type Manual Automatic Automatic

Axle

Axle Ratio 3.76 4.33 5.29

Advanced Axle Lubrication No No No

6 x 2 Axle No No No

Idle Reduction

Neutral Idle No No No

Stop-Start No No No

Tires

Steer Tire CRR 7.7 7.7 7.7

Drive Tire CRR 7.7 7.7 7.7

Tire Loaded Radius 0.483 0.483 0.483

Weight Reduction (lbs) No No No
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Table 2-44 Medium Heavy-Duty User-Enterable Modeling Parameters for Vocational Baseline

GEM INPUT MHD (CLASS 6-

7)

MHD (CLASS 6-

7)

MHD (CLASS 6-7)

Regional Duty 

Cycle 

Multi-Purpose 

Duty Cycle

Urban Duty Cycle

Transmission

Number of Forward Gears 5 5 5

Gear Ratio for Each Gear 3.102, 1.8107, 

1.4063, 1, 0.7117

3.102, 1.8107, 

1.4063, 1, 0.7117

3.102, 1.8107, 

1.4063, 1, 0.7117

Architecture Type Automatic Automatic Automatic

Axle

Axle Ratio 4.33 4.88 4.88

Advanced Axle Lubrication No No No

6 x 2 Axle No No No

Idle Reduction

Neutral Idle No No No

Stop-Start No No No

Tires

Steer Tire CRR 7.7 7.7 7.7

Drive Tire CRR 7.7 7.7 7.7

Tire Loaded Radius 0.462 0.462 0.426

Weight Reduction (lbs) No No No
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Table 2-45 Light Heavy-Duty User-Enterable Modeling Parameters for Vocational Baseline

GEM INPUT LHD (CLASS 2B5)LHD (CLASS 2B5)LHD (CLASS 2B5)

Regional Duty 

Cycle 

Multi-Purpose 

Duty Cycle

Urban Duty Cycle

Transmission

Number of Forward Gears 5 5 5

Gear Ratio for Each Gear 3.102, 1.8107, 

1.4063, 1, 0.7117

3.102, 1.8107, 

1.4063, 1, 0.7117

3.102, 1.8107, 

1.4063, 1, 0.7117

Architecture Type Automatic Automatic Automatic

Axle

Axle Ratio 4.1 4.56 4.56

Advanced Axle Lubrication No No No

6 x 2 Axle No No No

Idle Reduction

Neutral Idle No No No

Stop-Start No No No

Tires

Steer Tire CRR 7.7 7.7 7.7

Drive Tire CRR 7.7 7.7 7.7

Tire Loaded Radius 0.378 0.378 0.378

Weight Reduction (lbs) No No No

2.9.2.1 Setting Normalized Vocational Vehicle Baselines

The agencies developed adjusted, normalized vocational vehicle GEM numerical 

baselines, from which the improvements due to the technology packages would be set. This 

process began with simulating the performance of each of the nine baseline vehicles defined 

above. In this simulation, the emissions for curb idle transmission torque were calculated for 

each vehicle over the idle cycle. 

Next, the best performing vehicle in each weight class was identified. For the HHD 

weight class, this was the Regional vehicle. For the MHD and LHD weight classes, these were 

the Urban vehicles. Next, we calculated a normalization factor for each of the nine subcategories 

by dividing each GEM result of the best vehicle by the fleet weighted average result per weight 

class of the best vehicle. For each weight class, we assumed that 25 percent of the vehicles 

would use the Regional cycle, 50 percent would use the Multipurpose cycle, and 25 percent 

would use the Urban cycle. Then, we calculated a population-weighted result of the actual 

baseline GEM results in each weight class group using a presumed population distribution (25-

50-25). Finally, we calculated the normalized baseline values for each of nine subcategories by

multiplying the weighted baseline GEM result in each weight class by each respective 

normalization factor for that subcategory. This process is summarized in Table 2-46.
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Table 2-46 Vocational Baseline Normalizing

CLASS 2B-5 CLASS 6-7 CLASS 8

Urban MultiPurposeRural, 

Regional

Urban MultiPurposeRural, 

Regional

Urban MultiPurposeRural, 

Regional

Straight GEM Baseline Performance

318 328 331 200 204 199 223 216 187

Normalization Factor

0.97 1.00 1.04 1.00 1.01 0.99 1.01 1.02 0.96

Population Weighted Best Vehicle Result

328.8 202.4 193.9

Population Weighted Baseline Result

326.3 201.8 210.5

Normalized Baseline

316 325 339 201 203 199 212 214 203

2.9.2.2 Assigning Vocational Vehicles to Subcategories

To determine appropriate engine speed cut-points for subcategory assignments, the 

agencies conducted GEM simulations for each of the nine defined baseline vocational vehicles 

using a sweep of axle ratios ranging from 2.47:1 to 12:1. We then compared the CO2 emission 

rates of the composite cycle to assess the sensitivity of the results to axle ratio, and identified the 

axle ratio for which the emission rate was lowest, and thus most optimized for that vehicle and 

duty cycle. Next the agencies compared the engine speeds attained during the 55 mph and 65 

mph cruise cycles for the optimized axle ratio simulation to the maximum engine test speed of 

the engine in each simulated vehicle. The diesel engines in each simulated vehicle are described 

above in Chapter 2.9.1. The agencies used two gasoline engine models for this analysis, which 

were not used for derivation of the proposed standards. 

We noted considerable variability in the ratio of attained engine speed at 55 mph vs.

maximum test speed, but we reasoned that if an engine was rotating close to the engine’s rated 

speed (represented by a high percent of maximum test speed) while the vehicle is at 55 mph then 

it would logically be best certified using the Urban Duty Cycle. Based on our observations and 

good engineering judgment, we selected a cutpoint for the Urban Duty Cycle where a vehicle at 

55 mph would have an engine working above 90 percent of maximum engine test speed for 

vocational vehicles powered by diesel engines and above 50 percent for vocational vehicles 

powered by gasoline engines. We similarly noted considerable variability in the ratio of attained 

engine speed at 65 mph vs. maximum test speed, but we reasoned that if an engine was rotating 

slowly (represented by a low percent of maximum test speed) while the vehicle is at 65 mph then 

it would logically be best certified using the Regional Duty Cycle. Based on our observations 

and good engineering judgment, we selected a cutpoint for the Regional Duty Cycle where a 

vehicle at 65 mph would have an engine working below 75 percent of maximum engine test 

speed for vocational vehicles powered by diesel engines and below 45 percent for vocational 

vehicles powered by gasoline engines. The proposed regulations describe this subcategory

assignment process at 40 CFR 1037.510.
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2.9.3 Costs and Effectiveness of Vocational Vehicle Technologies

The following paragraphs describe the vehicle-level technologies on which the proposed 

vocational vehicle standards are predicated, and their projected effectiveness over the proposed 

test cycles. The methodology for estimating costs, including indirect cost estimates and learning 

effects, is described in draft RIA Chapter 2.12.1. Certain elements of the cost estimating 

methodology are the same as for the Phase 1 program, but as described in that section, certain 

elements are different, including how the agencies apply the markups, how the markups change 

with time, and which cost elements are influenced by learning effects. As a result of different 

technology complexities, learning effects, and different short-term and long-term warranty and 

non-warranty-related indirect costs, some technology costs identified below may appear higher 

in MY 2021 than in MY 2027. These differences are not due to changes in adoption rates, since 

the costs in Chapter 2.12 and below in Chapter 2.9.3 to 2.9.4 are for applying a given technology

to a single vehicle. Throughout this Chapter, where a dollar cost is given for a technology, note 

that these are adjusted to be valued as year 2012 dollars. Average costs for vocational vehicle 

technology packages, including adoption rates, are presented below in Chapter 2.9.5. Detailed 

descriptions of technology packages for SI engines can be found in the draft RIA Chapter 2.6. 

Detailed descriptions of technology packages and costs for CI engines can be found in the draft 

RIA Chapter 2.7. 

2.9.3.1 Transmissions

Transmission improvements present a significant opportunity for reducing fuel 

consumption and CO2 emissions from vocational vehicles. Transmission efficiency is important 

for many vocational vehicles as their duty cycles involve high percentages of driving under 

transient operation. The three categories of transmission improvements the agencies considered 

for Phase 2 are driveline optimization, architectural improvements, and hybrid powertrain 

systems.

Of the technologies described above in Chapter 2.4, the agencies are predicating the 

proposed vocational vehicle standards on performance improvements achieved by use of 

advanced transmissions as described in Table 2-47, below. The projected market adoption rates 

that inform the technology packages are described in Chapter 2.9.5.
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Table 2-47 Projected Vocational Transmission Improvements over GEM Baseline

TRANSMISSION 

TECHNOLOGY

PROJECTED 

IMPROVEMENT 

OVER TEST 

CYCLE

A

REGIONAL 

COMPOSITE 

CYCLE

MULTI-PURPOSE 

COMPOSITE 

CYCLE

URBAN 

COMPOSITE 

CYCLE

Two More Gears

(over 5-speed)

ARB Transient 2% 1.1 1.7 1.9

55 mph Cruise 0%

65 mph Cruise 0%

DCT or AMT 

(over automatic)

ARB Transient 4% 2.1 3.4 3.8

55 mph Cruise 0%

65 mph Cruise 0%

HHD DCT or 

AMT (over 

manual)b

ARB Transient 4% 2.3 (2.95) N/A N/A

55 mph Cruise 1.5%

65 mph Cruise 1.5%

Strong Hybrid ARB Transient 27% 14.7 22.9 25.6

55 mph Cruise 0%

65 mph Cruise 0%

Deep Driveline 

Integration

ARB Transient 7% 4.7 6.2 6.7

55 mph Cruise 2%

65 mph Cruise 2%

Notes: 

a

Improvement is relative to a 5-speed automatic transmission in GEM, except where noted. Technology 

improvements would either be modeled in GEM or would be measured over the powertrain test, except as noted.

b

Fixed improvement for HHD AMT or DCT vs. manual transmission in GEM would be 2.3 percent as shown, in 

addition to the GEM-modeled improvement of one percent over the ARB Transient and zero over the cruise cycles.

Combined these would be 2.95 percent.

2.9.3.1.1 Deep Integration - Conventional

The agencies believe an effective way to derive efficiency improvements from a 

transmission is by optimizing it with the engine and other driveline components to balance both 

performance needs and fuel savings. However, many vocational vehicles today are not operating 

with such optimized systems. Due to the fact that customers are able to specify their preferred 

components in a highly customized build process, many vocational vehicles are assembled with 

components that were designed more for compatibility than for optimization. To some extent, 

vertically integrated manufacturers are able to optimize their drivelines. However, this is not 

widespread in the vocational vehicle sector, resulting, primarily, from the multi-stage 

manufacture process. The agencies thus project that transmission and driveline optimization 

would yield a substantial proportion of vocational vehicle fuel efficiency improvements for 

Phase 2. On average, we anticipate that efficiency improvements of about five percent can be 

achieved from optimization, sometimes called deep integration, of drivelines. However, we are 

not assigning a fixed level of improvement; rather we have developed a test procedure, the 

powertrain test, for manufacturers to use to obtain improvement factors representative of their 

systems. See the draft RIA Chapter 3 for a discussion of this test procedure. Depending on the 

test cycle and level of integration, the agencies believe improvement factors greater than ten 

percent above the baseline vehicle performance could be achieved. To obtain such benefits 
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across more of the vocational vehicle fleet, the agencies believe there is opportunity for 

manufacturers to form strategic partnerships and explore commercial pathways to deploy deeper 

driveline integration. For example, one partnership of an engine manufacturer and a 

transmission manufacturer has led to development of driveline components that deliver improved 

fuel efficiency based on optimization that could not be realized without sharing of critical 

data.117

The agencies project other related transmission technologies would be recognized over 

the powertrain test along with driveline optimization. These include improved mechanical gear 

efficiency, more sophisticated shift strategies, more aggressive torque converter lockups, 

transmission friction reduction, and reduced parasitic losses.118 Each of these attributes would be 

simulated in GEM using default values, unless the powertrain test were employed. The expected 

benefits of improved gear efficiency, shift logic, and torque converter lockup are included in the 

total projected effectiveness of optimized conventional transmissions using the powertrain test.

For conventional powertrains, the agencies are projecting effectiveness of deep integration from 

3.5 to 4.8 percent, as shown in Table 2-47 above.

The agencies estimate the total cost to apply a high efficiency gearbox, aggressive shift 

logic, and early torque converter lockup to a vocational vehicle at $372 in MY 2021 and $315 in 

MY 2027, as described in draft RIA 2.12.3.5. The agencies describe the capital and operational 

expenses of conducting powertrain testing in the draft RIA Chapter 7.1.

2.9.3.1.2 Architectural Transmission Improvements

One type of architectural improvement the agencies project can reasonably be developed 

by manufacturers of all transmission architectures is increased number of gears. The benefit of 

adding more gears varies depending on whether the gears are added in the range where most 

operation occurs. The TIAX 2009 report projected that 8-speed transmissions could 

incrementally reduce fuel consumption by 2 to 3 percent over a 6-speed automatic transmission, 

for Class 3-6 box and bucket trucks, refuse haulers, and transit buses.119 Although the agencies 

estimate the improvement could on average be about two percent for the adding of two gears in 

the range where significant vehicle operation occurs, we are not assigning a fixed improvement 

based solely on number of transmission gears. Manufacturers would enter the number of gears 

and gear ratios into GEM and the model would simulate the efficiency benefit over the 

applicable test cycle. The agencies estimate the total cost to add two gears to a vocational vehicle 

transmission at $495 in MY 2021 and $457 in MY 2027, as described in draft RIA 2.12.3.1.

Transmission efficiency could also be improved in the time frame of the proposed rules 

by changes in the architecture of conventional transmissions. Most vocational vehicles currently 

use torque converter automatic transmissions (AT), especially in Classes 2b-6. According to the 

2009 TIAX report, approximately 70 percent of Class 3-6 box and bucket trucks use AT, and all 

refuse trucks, urban buses, and motor coaches use AT. 118 AT’s offer acceleration benefits over 

drive cycles with frequent stops, which can enhance productivity. However, with the diversity of 

vocational vehicles and drive cycles, other kinds of transmission architectures can meet customer 

needs, including automated manual transmissions (AMT) and even some manual transmissions 

(MT).120 
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Other architectural changes that the agencies project would offer efficiency

improvements include improved automated manual transmissions (AMT) and introduction of 

dual clutch transmissions (DCT). Newer versions of AMT are showing significant improvements 

in reliability, such that the current generation of transmissions with this architecture is more 

likely to retain resale value and win customer acceptance than early models.

121

 The agencies 

believe AMT generally compare favorably to manual transmissions in fuel efficiency, and while 

the degree of improvement is highly driver-dependent, it can be two percent or greater, 

depending on the drive cycle. See Chapter 2.4.4 for additional discussion of AMT. The agencies 

are not assigning fixed average performance levels to compare an AMT with a traditional 

automatic transmission. Although the lack of a torque converter offers AMT an efficiency

advantage in one respect, the lag in power during shifts is a disadvantage. For Phase 2, the 

agencies have developed validated models of both AMT and AT, as described in the draft RIA 

Chapter 4. Manufacturers installing AMT or AT would enter the relevant inputs to GEM and the 

simulation would calculate the performance. Dual clutch transmissions (DCT) are already in 

production for light-duty vehicles, and are expected to become available in the vocational vehicle 

market prior to the proposed beginning of Phase 2 in MY 2021.122 Based on supplier 

conversations, manufacturers intend to match varying DCT designs with the diverse needs of the 

heavy-duty market. The agencies do not yet have a validated DCT model in GEM, and we are 

not assigning a fixed performance level for DCT, though we expect the per-vehicle fuel 

efficiency improvement due to switching from automatic to DCT to be in the range of three 

percent over the GEM vocational vehicle test cycles. Selection of transmission architecture type 

(Manual, AMT, AT, DCT) would be made by manufacturers at the time of certification, and 

GEM would either use this input information to simulate that transmission using algorithms as 

described in the draft RIA Chapter 4, or fixed improvements may be assigned. The agencies are 

proposing to assign fixed levels of improvement that vary by test cycle in GEM for AMT when 

replacing a manual, which for vocational vehicles would be in the HHD Regional subcategory. 

If a manufacturer elected not to conduct powertrain testing to obtain specific improvements for 

use of a DCT, GEM would simulate a DCT as if it were an AMT, with no fixed assigned benefit.

According to EPA’s light-duty teardown report, the direct incremental cost to build a sixspeed wet dual clutch transmission was determined to be roughly $100 less than the cost of a sixspeed automatic transmission.123

 We estimate the components and engineering to design a 

heavy-duty torque converter automatic transmission are at least as costly and complex as those to 

design a dual clutch transmission. Therefore, the agencies estimate switching from AT to DCT 

would have zero incremental cost for vocational vehicles. 

The agencies have estimated the costs of upgrading from HHD manual transmissions to 

AT, AMT, and DCT, as summarized in Table 2-48, and described in detail below in 2.12.3. 

Table 2-48 Incremental Costs for HHD Transmissions Relative to Manual Transmissionsa

TECHNOLOGY 2021 COST 2027 COST

Manual to AMT $4,472 $3,795

Manual to AT $3,764 $3,470

Manual to DCT $4,472 $3,795

Note:

a Costs include markups (2012$)
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2.9.3.1.3 Deep Integration - Hybrid

The agencies are including hybrid powertrains as a technology on which the proposed 

vocational vehicle standards are predicated. We project a variety of mild and strong hybrid 

systems, with a wide range of effectiveness. Mild hybrid systems that offer an engine stop-start 

feature are discussed below under workday idle reduction. For hybrid powertrains, we are 

estimating a 22 to 25 percent fuel efficiency improvement over the powertrain test, depending on 

the duty cycle in GEM for the applicable subcategory. The agencies obtained these estimates by

projecting a 27 percent effectiveness over the ARB Transient cycle, and zero percent over the 

highway cruise cycles. With the proposed cycle weightings, depending on the subcategory, this 

is projected to yield a 25 to 26 percent improvement over the Urban cycle, and 22 to 23 percent 

improvement over the Multi-Purpose cycle. According to the NREL Final Evaluation of UPS 

Diesel Hybrid-Electric Delivery Vans, the improvement of a hybrid over a conventional diesel in 

gallons per ton-mile on a chassis dynamometer over the NYC Composite test cycle was 28 

percent.124 NREL characterizes the NYC Composite cycle as more aggressive than most of the 

observed field data points from the study, and may represent an ideal hybrid cycle in terms of low 

average speed, high stops per mile, and high kinetic intensity (KI). NREL noted that most of the 

observed field data points were reasonably represented by the HTUF4 cycle, over which the chassis 

dynamometer results showed a 31 percent improvement in gallons per ton-mile. In units of grams 

CO2 per mile, NREL reported these test results as 22 percent improvement over the NYC Composite 

cycle and 26 percent improvement over the HTUF4 cycle. Based on these results, and the fact that 

any improvement from strong hybrids in Phase 2 would not be simulated in GEM, rather evaluated 

using the powertrain test, the agencies deemed it reasonable to estimate a conservative 27 percent 

effectiveness over the ARB Transient in setting the stringency of the standards. 

Hybrid powertrain systems are included under transmission technologies because, 

depending on the design and degree of hybridization, they may either replace a conventional 

transmission or be deeply integrated with a conventional transmission. Further, these systems are 

often manufactured by companies that also manufacture conventional transmissions.

The Phase 1 standards were not predicated on any adoption of hybrid powertrains in the 

vocational vehicle sector. Because the first implementation year of Phase 1 came just three years 

after promulgation, it did not offer an opportunity to provide the lead time for development of 

technology. The agencies believe the Phase 2 rulemaking would offer sufficient lead time to 

develop, demonstrate, and conduct reliability testing for technologies that are still maturing.

Several types of vocational vehicles are well suited for hybrid powertrains, and tend to be 

early adopters of this technology. Vehicles such as utility or bucket trucks, delivery vehicles, 

refuse haulers, and buses have operational usage patterns with either a significant amount of 

stop-and-go activity or spend a large portion of their operating hours idling the main engine to 

operate a PTO unit. 

The industry is currently developing many variations of hybrid powertrain systems.

There are a few hybrid systems in the heavy-duty market today and several more under 

development. In addition, energy storage systems are getting better.125 Heavy-duty customers 

are getting used to these systems with the number of demonstration products on the road. Even 

so, manufacturers are uncertain how much investment to make in this technology without clear 
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signals from regulators. A list of hybrid manufacturers and their products intended for the 

vocational market is provided in Table 2-49. 

Table 2-49 Examples of Hybrid Manufacturers

MANUFACTURER PRODUCT EXAMPLE APPLICATION

Hino Class 5 cab-over-engine batteryelectric hybridDelivery Trucks

Allison HHD parallel hybrid Transit Bus

BAE HHD series or parallel hybrid Transit Bus

XL Class 3-4 mild electric hybrid Shuttle Bus

Crosspoint Kinetics Class 3-7 mild electric hybrid Delivery trucks, shuttle buses

Lightning Hybrids Class 2-5 hydraulic hybrid Delivery trucks

Parker Hannifin MHD hydraulic hybrid Delivery trucks

Freightliner Custom Chassis MHD hydraulic hybrid Delivery trucks

Morgan Olson MHD hydraulic hybrid Delivery trucks

Autocar-Parker Runwise hydraulic hybrid Refuse Trucks

Eatona HHD parallel electric hybrid Trucks and Buses

Odyne Plug-in electric hybrid, E-PTO Utility Trucks

Note:

a Currently selling in markets outside the U.S.

Some low cost products on the simple end of the hybrid spectrum are available that 

minimize battery demand through the use of ultra-capacitors or only provide power assist at low 

speeds. Our regulations define a hybrid system as one that has the capacity for energy storage.M 

Unofficially, some systems are commonly known as mild hybrids, where some accessories are 

electrified, the engine is not downsized and there may or may not be capacity for regenerative 

braking. Strong hybrids are typically referred to as those that have larger energy storage capacity 

such that the engine may be downsized in some cases. Depending on the drive cycle and units of 

measurement, strong hybrids developed to date have seen fuel consumption and CO2 emissions 

reductions between 20 and 50 percent in the field.126 

The agencies estimate the total cost of a hybrid powertrain system for a LHD vocational 

vehicle at $15,207 in MY 2021 and $11,791 in MY 2027. For a MHD vocational vehicle, the 

total cost is estimated at $23,904 in MY 2021 and $18,534 in MY 2027. For a HHD vocational 

vehicle, the total cost is estimated at $39,919 in MY 2021 and $30,952 in MY 2027, as described 

in draft RIA 2.12.7. The estimated higher costs for heavier vehicles are related to higher power 

demands and greater energy storage needs. These estimates assume no engine downsizing in the 

design of hybrid packages. This is in part to be conservative in our cost estimates, and in part 

because in some applications a smaller engine may not be acceptable if it would risk that 

performance could be sacrificed during some portion of a work day.

 

M NHTSA’s and EPA’s regulations define a hybrid vehicle as one that “includes energy storage features ... in 

addition to an internal combustion engine or other engine using consumable chemical fuel....” 49 CFR 535.4 and 40 

CFR 1037.801.
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2.9.3.2 Axles

The agencies are considering two axle technologies for the vocational sector. The first is 

advanced low friction axle lubricants. SwRI tested improved driveline lubrication and found 

measurable improvements by switching from current mainstream products to top-tier 

formulations focusing on modified viscometric effects.

127 The agencies believe that a 0.5 

percent improvement in vocational vehicle efficiency (as for tractors) is achievable through the 

application of low friction axle lubricants, and have included that value as a fixed technology

improvement value in GEM. If a manufacturer wishes to demonstrate a greater benefit, an axle 

efficiency test could be performed to support an application for an innovative technology credit. 

See draft RIA Chapter 3 for a description of a test procedure for axle efficiency. We are 

estimating the axle lubricating costs for HHD to be the same as for tractors since those vehicles 

likewise typically have three axles. However, for LHD and MHD vocational vehicles, we scaled 

down the cost of this technology to reflect the presence of a single rear axle. The agencies 

estimate the total cost of low friction axle lubricants on a LHD or MHD vocational vehicle (with 

2 axles) at $132 in MY 2021 and $114 in MY 2027. For HHD vocational vehicles (with 3 

axles), the agencies estimate the cost at $197 in MY 2021 and $172 in MY 2027, as described in 

draft RIA 2.12.5.4.

The second axle technology the agencies are considering is a design that enables one of 

the tandem axles to temporarily disconnect or permanently be a non-driven axle, on vehicles 

with two rear (drive) axles, commonly referred to as a 6x2 configuration. The agencies have 

considered two types of 6x2 configurations for vocational vehicles: those that are engaged full 

time on a vehicle, and those that may be engaged only during some types of vehicle operation, 

such as only when operating at highway cruise speeds. In prior years, manufacturers offered 

versions of this technology that were not accepted by vehicle owners. When the second drive 

axle is no longer powered, traction may be sacrificed in some cases. Vehicles with earlier 

versions of this technology have seen reduced residual values in the secondary market.128 Over 

the model years covered by the Phase 2 rules, the agencies expect the market to offer 

significantly improved versions of this technology, with traction control maintained at lower 

speeds and efficiency gains at highway cruise speeds.129 Mechanisms to automatically

disconnect or reconnect drive axles would likely function in a similar manner as with two axle 

vehicles that can seamlessly switch from four-wheel drive to two-wheel drive and back. Further 

information about 6x2 axle technology is provided in the feasibility of the tractor standards, 

preamble Section III, as well as in draft RIA Chapter 2.4. 

The efficiency benefit of a 6x2 axle configuration is highly duty-cycle dependent. In 

many instances, vocational vehicles need to operate off-highway, such as at a construction site 

delivering materials or dumping at a refuse collection facility. Under these conditions, vehicles 

with two drive axles may need the full tractive benefit of both drive axles. The 6x2 axle 

disconnect technology is not expected to measurably improve a vehicle’s efficiency for vehicles 

whose normal duty cycle is performing off-highway work, but the agencies do expect this 

technology to be recognized on a cycle with a significant weighting of highway cruise. The 

agencies estimate the total cost of full time 6x2 at $197 in MY 2021 and $172 in MY 2027. The 

agencies estimate the total cost of part time 6x2 on a vocational vehicle at $120 in MY 2021 and 

$116 in MY 2027, as described in draft RIA 2.12.5.2.
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Some vocational vehicles in the HHD Regional subcategory may see a 6x2 axle 

disconnect technology as a reasonable option for improving fuel efficiency. As in Phase 1, our 

vehicle simulation model assumes that only HHD vehicles have two rear axles, so only these 

could be recognized for adopting this technology. Further, the agencies don’t believe vehicles in 

the Multipurpose and Urban subcategories operate with a significant enough highway time to 

make this technology worthwhile. While the agencies project this can achieve over 2 percent 

benefit at highway cruise, we propose to assign a fixed 2.5 percent value in GEM for part time

6x2 over the highway cruise cycles and zero over the ARB Transient cycle, where the specific 

benefit would be calculated according to the composite weighting of the applicable vocational 

vehicle test cycle.130

2.9.3.3 Lower Rolling Resistance Tires

Tires are the second largest contributor to energy losses of vocational vehicles, as found 

in the energy audit conducted by Argonne National Lab.131 There is a wide range of rolling 

resistance of tires used on vocational vehicles today. This is in part due to the fact that the 

competitive pressure to improve rolling resistance of vocational vehicle tires has been less than 

that found in the line haul tire market. In addition, the drive cycles typical for these applications 

often lead vocational vehicle buyers to value tire traction and durability more heavily than rolling 

resistance. The agencies acknowledge there can be tradeoffs when designing a tire for reduced 

rolling resistance. These tradeoffs can include characteristics such as wear resistance, cost and 

scuff resistance. NHTSA, EPA, and ARB met with stakeholders from the tire industry

(Bridgestone, Continental, Cooper, Goodyear, and Michelin) to discuss the next generation of 

lower rolling resistance (LRR) tires for the Phase 2 timeframe for all segments of Class 2b-8 

vehicles, including trailers. Manufacturers discussed forecasts for rolling resistance levels and 

production availability in the Phase 2 timeframe, as well as their plans for improving rolling 

resistance performance while maintaining other performance parameters such as traction, 

handling, wear, mass reduction, retreadability, and structural durability. 

The meetings included specific discussions of the impacts of the current generation of 

LRR tires on vehicle stopping distance and handling. Manufacturers indicated no known safety 

disbenefit in the current on-road fleet from use of LRR tires. While the next generation of tires 

may require some tradeoffs in wear performance and costs over the next 10 years to achieve 

better tire rolling resistance performance, manufacturers said they will not trade off safety for 

performance. They also emphasized that keeping tires inflated (through proper maintenance or 

automatic systems) was the best way to assure long term fuel efficiency and safety during 

vehicle operation.

According to the 2015 NHTSA Technology Study, vocational vehicles are likely to see 

the most benefits from reduced tire rolling resistance when they are driving at 55 mph.132 This 

report also found an influence of vehicle weight on the benefits of LRR tires. The study found 

that both vocational vehicles tested had greater benefits of LRR tires at 100 percent payload than 

when empty. Also, the T270 delivery box truck that was 4,000 pounds heavier when fully 

loaded saw slightly greater efficiency gains from LRR tires than the F650 flatbed tow truck over 

the same cycles. At higher speeds, aerodynamic drag grows, which reduces the rolling resistance 

share of total vehicle power demand. In highly transient cycles, the power required to accelerate 

the vehicle inertia overshadows the rolling resistance power demand. In simulation, GEM 
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represents vocational vehicles with fixed vehicle weights, payloads and aerodynamic 

coefficients. Thus, the benefit of LRR tires would be reflected in GEM differently for vehicles 

of different weight classes. There will also be further differences arising from the different test

cycles. Based on preliminary simulations, it appears the vehicles in GEM most likely to see the 

greatest fuel efficiency gains from use of LRR tires are those in the MHD weight classes tested 

over the Regional or Multipurpose duty cycles, where one percent efficiency improvement could 

be achieved by reducing CRR by four to five percent. Those seeing the least benefit from LRR 

tires would likely be Class 8 vocational vehicles tested over the Urban or Multipurpose cycles,

where one percent efficiency improvement could be achieved by reducing CRR by seven to eight 

percent.

As shown in draft RIA Chapter 2.12.8, the agencies estimate the total cost to apply LRR 

tires that have five percent lower CRR than baseline to be the same as the cost to apply baselinelevel LRR tires. The agencies estimate the cost to apply LRR tires that have 10 percent lower 

CRR than baseline to be about $4 more than the cost of baseline tires. The agencies estimate the 

cost to apply LRR tires that have 15 percent lower CRR than baseline to be about $6 more than 

the cost of baseline tires. Based on these costs, some illustrations of the costs associated with 

LRR tires are provided. To fit a LHD or MHD vocational vehicle with two steer tires improved 

by 10 percent and 4 drive tires improved by 5 percent would be roughly $9 to $10 in MY 2021 

as well as in MY 2024. Based on the estimated zero-cost to upgrade the drive tires by five 

percent, we estimate the cost to fit a HHD vocational vehicle (with 10 tires) with the same CRR 

upgrades would be roughly the same, $9 to $10.

As another example, to fit a LHD or MHD vocational vehicle with two steer tires 

improved by 15 percent and 4 drive tires improved by 10 percent, it is estimated to cost $33 in 

MY 2024. For a HHD vehicle (with 8 drive tires) to make the same CRR upgrades, we estimate 

the cost to be $54 in MY 2024. Detailed tables of LRR tire costs in each year are provided in 

draft RIA Chapter 2.12.8.

The agencies propose to continue the light truck (LT) tire CRR adjustment factor that was 

adopted in Phase 1. See generally 76 FR 57172-74. In Phase 1, the agencies developed this

adjustment factor by dividing the overall vocational test average CRR of 7.7 by the LT 

vocational average CRR of 8.9. This yielded an adjustment factor of 0.87. After promulgation of 

the Phase 1 rules, the agencies conducted additional tire CRR testing on a variety of LT tires, 

most of which were designated as all-position tires. In addition, manufacturers have submitted to 

the agencies pre-certification data that include CRR values provided by tire suppliers. For the 

small subset of newer test tires that were designated as steer tires, the average CRR was 7.8 

kg/ton. For the subset of newer test tires that were designated as drive tires, the average CRR 

was 8.6 kg/ton. However all-position tires had an average CRR of 8.9 kg/ton.133 Therefore, for 

LT vocational vehicle tires, we propose to continue allowing the measured CRR values to be 

multiplied by the 0.87 adjustment factor before entering the values in the GEM for compliance, 

because this additional testing has not revealed compelling information that a change is needed. 

2.9.3.4 Workday Idle Reduction

The Phase 2 idle reduction technologies considered for vocational vehicles are those that 

reduce workday idling, unlike the overnight idling of combination tractors. There are many 
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potential such technologies. The agencies in particular evaluated neutral idle and stop-start 

technologies, and the proposed standards are predicated on projected amounts of penetrations of 

these technologies. While neutral idle is necessarily a transmission technology, stop-start could 

range from an engine technology to one that would be installed by a secondary manufacturer 

under a delegated assembly agreement. 

The agencies are aware that for a vocational vehicle’s engine to turn off during workday 

driving conditions, there must be a reserve source of energy to maintain functions such as power 

steering, cabin heat, and transmission pressure, among others. Stop-start systems can be viewed 

as having a place on the low-cost end of the hybridization continuum. The agencies are 

including the cost of energy storage sufficient to maintain critical onboard systems and restart the 

engine as part of the cost of vocational vehicle stop-start packages. The technologies to capture 

this energy could include a system of photovoltaic cells on the roof of a box truck, or 

regenerative braking. The technologies to store the captured energy could include a battery or a 

hydraulic pressure bladder. According to CALSTART’s report to the NAFA 2014 Institute and 

Expo, examples of suppliers of on-vehicle energy storage systems that can enable idle reduction 

include Altec, Terex, and Time. More discussion of stop-start technologies is found in the draft 

RIA Chapter 2.4.

The agencies are also proposing a certification test cycle, as described in draft RIA 

Chapter 3.4.2, which measures the amount of fuel saved and CO2 reduced by these two primary

types of technologies: neutral idle and stop-start. Vocational vehicles frequently also idle while 

cargo is loaded or unloaded, and while operating a PTO such as compacting garbage or operating 

a bucket. In these rules, the agencies are proposing that the Regional duty cycle have ten percent 

idle, the Multi-purpose cycle have 15 percent idle, and the Urban cycle have 20 percent idle. 

These estimates are based on some publically available data published by NREL.

134

 Figure 2-16

depicts a chart that illustrates the type of data on zero-speed operation data from delivery trucks 

available from NREL on its Fleet DNA web site. However, because engine parameters were not 

captured during the data-logging of this vehicle activity, these data cannot distinguish between 

zero speed conditions with the engine off and zero speed conditions with the engine idling.
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Figure 2-16 Example Fleet DNA Vehicle Activity Data from NREL

Combining the publically available zero-speed frequency charts from NREL on delivery

trucks, service vans, delivery vans, and bucket trucks, the agencies observed that roughly half of 

the logged operating days had less than 10 percent time at zero speed, roughly 30 percent of the 

logged operating days had between 10 and 15 percent time at zero speed, roughly 20 percent of 

the logged operating days had between 15 and 20 percent time at zero speed, and roughly 6 

percent of the logged operating days had over 20 percent time at zero speed. School buses were 

excluded from this average, because the given distribution had two modes: over 40 percent of the 

school bus operating days logged had less than five percent time at zero speed, while nearly half 

of the logged operating days for those buses had roughly 40 percent time at zero speed.

Without actual engine information, if we assume all the zero speed time is idling, then

based on these rough estimates, it appears that 94 percent of these vehicles (excluding school 

buses) idle at frequencies of less than 20 percent on a daily basis. Thus, the agencies designed 

composite test cycles where the maximum weighting of idle was 20 percent. We assigned that 

value to the Urban cycle, where we expect a high incidence of traffic-related idling and city 

delivery routes involving frequent stops. The 15 percent and 10 percent idle weightings for the 

Multi-Purpose and Regional cycles, respectively, were selected as reasonably lesser values, 

given the distributions observed in the NREL charts. Table 2-50 presents a summary of this 

analysis.
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Table 2-50 Daily Zero Speed Percentage Distribution by Vehicle Type

LESS THAN 10 10 TO 14 15 TO 20 OVER 20

Service Vans 59% 18% 23% 0%

Delivery Trucks 76% 16% 9% 0%

Delivery Vans 38% 35% 2% 25%

Bucket Trucks 18% 45% 37% 0%

School Buses 41% 3% 7% 48%

Average 47% 23% 16% 15%

Average 

Without Buses

48% 28% 18% 6%

Because these data are not representative of the national vocational vehicle fleet, EPA has 

entered into an interagency agreement with NREL to further characterize workday idle among 

vocational vehicles. One task of this agreement is to estimate the nationally representative 

fraction of idle operation for vocational vehicles for each proposed regulatory subcategory. The 

preliminary range of daily idle operation per vehicle indicated by this work is about 18 to 33 

percent when combining the data from all available vehicles. An analysis of possible 

vocational vehicle standards derived from alternate characterizations of idle operation has been 

prepared by the agencies, and is available for review in the public docket for this rulemaking.135

Based on GEM simulations using the currently proposed vocational vehicle test cycles, 

the agencies estimate neutral idle for automatic transmissions to provide fuel efficiency

improvements ranging from one percent to four percent, depending on the regulatory

subcategory. The agencies estimate stop-start to provide fuel efficiency improvements ranging 

from 0.8 percent to seven percent, depending on the regulatory subcategory. Because of the 

higher idle weighting factor in the Urban test cycle, vehicles certified in these subcategories 

would derive the greatest benefit from applying idle reduction technologies. This presumes there 

is a correlation between amount of urban driving and amount of idle time.

Although the primary program would not simulate vocational vehicles over a test cycle 

that includes PTO operation, the agencies are proposing to continue, with revisions, the hybridPTO test option that was in Phase 1. See 40 CFR 1037.525 and 76 FR 57247. Recall that we are 

proposing to regulate vocational vehicles at the incomplete stage when a chassis manufacturer 

may not know at the time of certification whether a PTO will be installed or how the vehicle will 

be used. Although chassis manufacturers will certainly know whether a vehicle’s transmission is 

PTO-enabled, that is very different from knowing whether a PTO will actually be installed and 

how it will be used. Chassis manufacturers may rarely know whether the PTO-enabled vehicle 

will use this capability to maneuver a lift gate on a delivery vehicle, to operate a utility boom, or 

merely as a reserve item to add value in the secondary market. In cases where a manufacturer 

can certify that a PTO with an idle-reduction technology will be installed either by the chassis 

manufacturer or by a second stage manufacturer, the hybrid-PTO test cycle may be utilized by

the certifying manufacturer to measure an improvement factor over the GEM duty cycle that 

would otherwise apply to that vehicle. In addition, the delegated assembly provisions would 

apply. See preamble Section V.E for a description of the delegated assembly provisions. See 

draft RIA Chapter 3 for a discussion of the proposed revisions to the hybrid PTO test cycle. In 
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cases where a chassis manufacturer does not know whether a powertrain that is PTO-enabled 

will actually have a PTO-using tool installed, and whether there will be an energy storage system 

installed to save fuel during PTO operation, then the agencies do not see a way for the Phase 2

program to recognize hybrid PTO technology.

Our estimates are that applying neutral idle to a vocational vehicle with an automatic 

transmission would cost $9 in MY 2021, decreasing to $8 in MT 2027, as shown in draft RIA 

2.12.6. These costs are based on a small amount of engineering development and testing costs, 

with no hardware required. Our estimates are that the cost of applying stop-start to a vocational 

vehicle would vary by vehicle weight class. For LHD vocational vehicles, we estimate the total 

cost would range from $855 in MY 2021 to $709 in MY 2027. For MHD vocational vehicles, 

we estimate the total cost would range from $902 in MY 2021 to $748 in MY 2027. For HHD 

vocational vehicles, we estimate the total cost would range from $1,657 in MY 2021 to $1,374 in 

MY 2027. These costs, presented in draft RIA Chapter 2.12.6, are derived from costs reported 

by Tetra Tech for stop-start, along with costs for electrified accessories used in the light-duty

GHG program, and scaled up for heavier vehicles.

With either a stop-start engine feature or with a neutral idle transmission calibration, less 

fuel is burned at idle. Furthermore, it is expected that SCR catalyst function could be better 

managed when an engine shuts off than when it idles, because SCR systems are well insulated 

and can maintain temperature when an engine is shut off, however idling causes relatively cool 

air to flow through a catalyst. Therefore, the agencies have reason to believe there may be a NOX

co-benefit to stop-start idle reduction technologies, and possibly also to neutral idle. This would

be true if the NOX reductions from reduced fuel consumption and retained aftertreatment 

temperature were greater than any excess NOX emissions due to engine re-starts. 

2.9.3.5 Weight Reduction

The agencies believe there is opportunity for weight reduction in some vocational 

vehicles. The 2015 NHTSA Technology Study found that weight reduction provides a greater 

fuel efficiency benefit for vehicles driving under transient conditions than for those operating 

under constant speeds. In simulation, the study found that the two Class 6 trucks improved fuel 

efficiency by over two percent on the ARB transient cycle by removing 1,100 lbs. Further, 

SwRI observed that the improvements due to weight reduction behaved linearly.

136

 The 

proposed menu of components available for a vocational vehicle weight credit in GEM is 

presented in Table 2-52. It includes fewer options than for tractors, but the agencies believe 

there are a number of feasible material substitution choices at the chassis level, which could add 

up to weight savings on the order of a few hundred pounds. The agencies estimate the total cost 

to reduce the weight of a vocational vehicle by 200 pounds to be $683 in MY 2021 and $578 in 

MY 2027, as described in draft RIA 2.12.10.3. This is in the range of $3 to $4 per pound, as 

reported by TIAX 2009.137 

To assess the projected effectiveness of weight reduction of the proposed package of 200 

pounds, the agencies simulated a HHD, MHD and LHD vocational vehicle in GEM over each of 

the separate test cycles. Based on the results of this simulation, the agencies project a reduction 

of 200 pounds may yield a fuel efficiency improvement ranging from 0.8 percent to 2 percent 

over the ARB Transient cycle, depending on vehicle weight class. The results of this example 
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simulation are presented in Table 2-51. Consistent with the results of SwRI study mentioned 

above, these GEM results show a slightly greater benefit over transient operation than highway

cruise. 

Table 2-51 Projected Effectiveness of Vocational Weight Reduction

HHD MHD LHD

Weight Reduction 200 0 200 0 200 0

Static Test Weight (kg) 

19,006 

 

19,051 

 

11,363 

 

11,408 

 

7,212 

 

7,257 

Dynamic Test Weight (kg) 

19,573 

 

19,618 

 

11,703 

 

11,748 

 

7,552 

 

7,597 

Payload (ton) 7.55 7.5 5.65 5.6 2.9 2.85

Transient CO2 Emission (g CO2 ptm) 240 242 224 227 351 358

55mph CO2 Emission (g CO2 ptm) 181 182 182 184 332 338

65mph CO2 Emission (g CO2 ptm) 216 217 230 232 394 401

Effectiveness over Transient -0.8% -1.1% -2.0%

Effectiveness over 55 mph -0.7% -1.0% -1.8%

Effectiveness over 65 mph -0.7% -1.0% -1.8%

Urban Cycle Effectiveness (94% 

Transient, 6% 55 mph)

-0.8% -1.1% -2.0%

Multi-Purpose Cycle Effectiveness 

(82% Transient, 15% 55 mph, 3% 65 

mph)

-0.8% -1.1% -1.9%

Regional Cycle Effectiveness (50% 

Transient, 28% 55 mph, 22% 65 

mph)

-0.8% -1.0% -1.9%

Without more specific data on which to base our assumptions, the agencies are proposing 

to allocate 50 percent of any mass reduction to increased payload, and 50 percent to reduce the 

chassis weight. We considered the data on which the tractor weight allocation (1/3:2/3) is based, 

but determined this would not be valid for vocational vehicles, as the underlying data pertained 

only to long haul tractor-trailers. The agencies propose that 50 percent of weight removed from 

vocational vehicle chassis would be added back as additional payload in GEM. This suggests an 

equal likelihood that a vehicle would be reducing weight for benefits of being lighter, or 

reducing weight to carry more payload.

One reason why this effectiveness appears greater than would be expected based on the 

SwRI results is the change in payload. As shown in Table 2-51, this payload attribute has a 

stronger influence on the effectiveness than the duty cycle. For the LHD vehicles, reducing 200 

pounds would decrease the test weight by 0.6 percent and increase the payload by 1.8 percent. 

The agencies project the effectiveness of weight reduction for Phase 2 would be one percent or 

less for HHD and MHD vocational vehicles, and the effectiveness would be close to two percent 

for LHD vehicles over any of the vocational vehicle composite cycles. 
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Table 2-52 Proposed Vocational Weight Reduction Technologies

COMPONENT MATERIAL

VOCATIONAL VEHICLE CLASS

Class 2b-5 Class 6-7 Class 8

Axle Hubs - Non-Drive Aluminum 40 40

Axle Hubs - Non-Drive High Strength Steel 5 5

Axle - Non-Drive Aluminum 60 60

Axle - Non-Drive High Strength Steel 15 15

Brake Drums - Non-Drive Aluminum 60 60

Brake Drums - Non-Drive High Strength Steel 8 8

Axle Hubs - Drive Aluminum 40 80

Axle Hubs - Drive High Strength Steel 10 20

Brake Drums - Drive Aluminum 70 140

Brake Drums - Drive High Strength Steel 5.5 11

Clutch Housing Aluminum 34 40

Clutch Housing High Strength Steel 9 10

Suspension Brackets, 

Hangers

Aluminum 67 100

Suspension Brackets, 

Hangers

High Strength Steel 20 30

Transmission Case Aluminum 45 50

Transmission Case High Strength Steel 11 12

Crossmember – Cab Aluminum 10 14 15

Crossmember – Cab High Strength Steel 2 4 5

Crossmember - NonSuspensionAluminum 15 18 21

Crossmember - NonSuspensionHigh Strength Steel 5 6 7

Crossmember -Suspension Aluminum 15 20 25

Crossmember -Suspension High Strength Steel 4 5 6

Driveshaft Aluminum 12 40 50

Driveshaft High Strength Steel 5 10 12

Frame Rails Aluminum 120 300 440

Frame Rails High Strength Steel 24 40 87

Wheels - Dual Aluminum 126 126 210

Wheels - Dual High Strength Steel 48 48 80

Wheels - Dual Lightweight 

Aluminum

180 180 300

Wheels - Wide Base Single Aluminum 278 278 556
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COMPONENT MATERIAL

VOCATIONAL VEHICLE CLASS

Class 2b-5 Class 6-7 Class 8

Wheels - Wide Base Single High Strength Steel 168 168 336

Wheels - Wide Base Single Lightweight 

Aluminum

294 294 588

Permanent 6x2 Axle 

Configuration

Multi N/A N/A 300

2.9.3.6 HFC Leakage

EPA believes the capacity of vocational vehicle air conditioning systems are sufficiently 

similar to those of other HD vehicles to apply a similar leakage standard as was applied in the 

HD Phase 1 program for tractors and HD pickup trucks and vans. Emissions due to direct 

refrigerant leakage are significant in all vehicle types. EPA is proposing a1.50 percent 

refrigerant leakage per year standard, to assure that high-quality, low-leakage components are 

used in the design of each air conditioning system with a refrigerant capacity greater than 733 

grams. Since refrigerant leakage past the compressor shaft seal is the dominant source of 

leakage in belt-driven air conditioning systems, the agency recognizes that this 1.50 percent 

leakage standard would not be feasible for systems with a refrigerant capacity of 733 grams or 

lower, as the minimum feasible leakage rate does not continue to drop as the capacity or size of 

the air conditioning system is reduced. The fixed leakage from the compressor seal and other 

system devices results in a minimum feasible yearly leakage rate, and further reductions in 

refrigerant capacity (the ‘denominator’ in the percent refrigerant leakage calculation) would 

result in a system which could not meet the 1.50 percent leakage per year standard. EPA does 

not believe that leakage reducing technologies will be available in MY 2021 to enable lower 

capacity systems to meet the percent per year standard, so we are proposing a maximum gram 

per year leakage standard of 11.0 grams per year for vocational vehicle air conditioning systems 

with a refrigerant capacity of 733 grams or lower, as was adopted in the HD Phase 1 program for 

tractors and HD pickup trucks and vans. 

The proposed standard is derived from the vehicles with the largest system refrigerant 

capacity based on the Minnesota GHG Reporting database.138 These are the same data on which 

the HD Phase 1 HFC leakage standard was based.139 

By requiring that all vocational vehicles achieve the leakage level of 1.50 percent per 

year, roughly half of the vehicles in the 2010 data sample would need to reduce their leakage 

rates, and an emissions reduction roughly comparable to that necessary to generate direct 

emission credits under the light-duty vehicle program would result. See 75 FR at 25426-247. 

However, no credits or trading flexibilities are proposed under this standard for heavy-duty 

vocational vehicles. We believe that a yearly system leakage approach would assure that highquality, low-leakage, components are used in each A/C system design, and we expect that 

manufacturers would reduce A/C leakage emissions by utilizing improved, leak-tight 

components. Some of the improved components available to manufacturers are low-permeation 

flexible hoses, multiple o-ring or seal washer connections, and multiple-lip compressor shaft 

seals. The availability of low leakage components in the market is being driven by the air 
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conditioning credit program in the light-duty GHG rulemaking (which applies to 2012 model 

year and later vehicles). EPA believes that reducing A/C system leakage is both highly costeffective and technologically feasible. The cooperative industry and government Improved 

Mobile Air Conditioning (IMAC) program has demonstrated that new-vehicle leakage emissions 

can be reduced by 50 percent by reducing the number and improving the quality of the 

components, fittings, seals, and hoses of the A/C system.140 All of these technologies are already 

in commercial use and exist on some of today’s A/C systems in other heavy-duty vehicles.

EPA is proposing to adopt the same compliance method for control of leakage from A/C 

systems in vocational vehicles as was adopted for the HD Phase 1 HFC leakage standard. Under 

this approach, manufacturers would choose from a menu of A/C equipment and components 

used in their vehicles in order to establish leakage scores, which would characterize their A/C 

system leakage performance and calculate the percent leakage per year as this score divided by

the system refrigerant capacity. The agencies estimate the total cost to apply low leakage A/C 

components to a vocational vehicle to be $22 in MY 2021 and $19 in MY 2027, as described in 

draft RIA 2.12.4.1.

Consistent with the Light-Duty Vehicle Greenhouse Gas Emissions rulemaking, a 

manufacturer would compare the components of its A/C system with a set of leakage reduction 

technologies and actions that is based closely on that being developed through IMAC and the 

Society of Automotive Engineers (as SAE Surface Vehicle Standard J2727, August 2008 

version).141 See generally 75 FR at 25426. The SAE J2727 approach was developed from 

laboratory testing of a variety of A/C related components, and EPA believes that the J2727 

leakage scoring system generally represents a reasonable correlation with average real-world 

leakage in new vehicles. Like the IMAC approach, our proposed approach would associate each 

component with a specific leakage rate in grams per year identical to the values in J2727 and 

then sum together the component leakage values to develop the total A/C system leakage. As is 

currently done for other HD vehicles, for vocational vehicles, the total A/C leakage score would 

then be divided by the total refrigerant system capacity to develop a percent leakage per year 

value.

2.9.4 Other Vocational Vehicle Technologies Considered

2.9.4.1 Vocational Aerodynamics

The agencies are not predicating the proposed standards on improved aerodynamics of 

vocational vehicles. However, the agencies are proposing to offer an option for manufacturers to 

receive recognition for a few specific aerodynamic technologies on vehicles where the criteria 

would be met to qualify for this credit, should a manufacturer decide to utilize the technology.

We are partnering with CARB to incorporate into GEM some data from testing that is 

being conducted by CARB through NREL. A test plan is in place to assess the fuel efficiency

benefit of three different devices to improve the aerodynamic performance of a Class 6 box 

truck, as well as two devices on a cutaway van. We propose that, if a manufacturer can certify

that a final vehicle configuration will closely match one of the configurations on which testing 

was conducted, then an option may be selected to improve that vehicle’s GEM score based on 

installation of the applicable aerodynamic devices. The amount of improvement would be set by
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EPA based on NREL’s test results. This credit provision would apply only to vocational 

vehicles certified over the Regional duty cycle. Manufacturers wishing to receive credit for 

other aerodynamic technologies or on other vehicle configurations would be able to apply for 

innovative credits using the established procedures.

Table 2-53 shows the vocational aerodynamic technologies that are being tested, for 

which credit could be available through GEM. The agencies have not estimated manufacturing 

costs for these technologies on vocational vehicles. We project that a manufacturer would only 

apply these where it was found to be cost-effective for the specific application. For a description 

of the costs estimated for applying aerodynamic technologies to tractors, see the draft RIA at 

Chapter 2.12.9, where the estimated cost for a Bin2 package on a low roof day cab tractor is 

shown to be roughly $1,000.

Table 2-53 Vocational Aerodynamic Technologies Being Assessed

VEHICLE SKIRTS FRONT 

FAIRING 

(NOSE 

CONE)

REAR

FAIRING

(TAIL)

WHEEL COVERS

Class 6 Box 

Truck

X X X

Class 4 Box 

Truck 

X

The vehicles eligible for this GEM-based credit would be those for which the chassis 

manufacturer can certify that, through a delegated assembly agreement, the final built 

configuration would be reasonably similar to the dimensions of one of the test vehicles. A 

description of vehicles and aerodynamic technologies that could be eligible for this option, as 

well as a description of the testing conducted to obtain the assigned GEM improvements due to 

these technologies, are presented in a memorandum to the docket.142

2.9.4.2 Electric Vehicles

Some heavy-duty vehicles can be powered exclusively by electric motors. Electric 

motors are efficient and able to produce high torque, giving e-trucks strong driving 

characteristics, particularly in stop-and-go or urban driving situations, and are well-suited for 

moving heavy loads. Electric motors also offer the ability to operate with very low noise, an 

advantage in certain applications. Currently, e-trucks have some disadvantages over 

conventional vehicles, primarily in cost, weight and range. Components are relatively expensive, 

and storing electricity using currently available technology is expensive, bulky, and heavy.

The West Coast Collaborative, a public-private partnership, has estimated the incremental 

costs for electric Class 3-6 trucks in the Los Angeles, CA, area.143 Compared to a conventional 

diesel, the WCC estimates a battery-electric vehicle system would cost between $70,000 and 

$90,000 more than a conventional diesel system. The CalHEAT Technology Roadmap includes 

an estimate that the incremental cost for a fully-electric medium- or heavy- duty vehicle would 

be between $50,000 and $100,000. In draft RIA Chapter 2.12.7.6, the agencies estimate the cost 
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of a full electric LHD or MHD vocational vehicle at $55,216 in MY 2021 and $52,128 in MY 

2024. The CalHEAT roadmap report also presents several actions that must be taken by

manufacturers and others, before heavy-duty e-trucks can reach what they call Stage 3 

Deployment.144 

Early adopters of electric drivetrain technology are medium-heavy-duty vocational 

vehicles that are not weight-limited and have drive cycles where they don’t need to go far from a 

central garage. According to CALSTART’s report to the NAFA 2014 Institute and Expo, there 

is an emerging market of MHD all-electric vocational vehicles, including models from Smith, 

EVI, Boulder, AMP, and others.

126 CalHEAT has published results of a comprehensive 

performance evaluation of three battery electric truck models using information and data from 

in-use data collection, on road testing and chassis dynamometer testing.145

Given the high costs and the developing nature of this technology, the agencies do not 

project fully electric vocational vehicles to be widely commercially available in the time frame 

of the proposed rules. For this reason, the agencies have not based the proposed Phase 2 

standards on adoption of full-electric vocational vehicles. However, in the more stringent 

alternatives discussed in detail in draft RIA Chapter 9, the agencies do project three percent 

adoption of full electric LHD and MHD vocational vehicles (only applicable for MY 2024 for 

Alternative 5). To the extent this technology is able to be brought to market in the time frame of

the Phase 2 program, there is currently a certification path for these chassis from Phase 1, as 

described in the Preamble Section V and in the regulations at 40 CFR 1037.150 and 49 CFR 

535.8.

2.9.5 Derivation of the Proposed Vocational Vehicle Technology Packages

The agencies are proposing standards for vocational vehicles predicated on the same suite 

of technologies in both the 2021 and 2024 MY implementation years. The change in stringency

between those years would be a result of different adoption rates of those technologies. Package 

costs for each model year are presented following each respective adoption rate discussion.

2.9.5.1 Projected Technology Adoption Rates for Vocational Vehicles

The agencies have estimated the extent to which technologies may be adopted by

manufacturers to meet the proposed 2021 vocational vehicle standards. 

2.9.5.1.1 Transmissions

The agencies project a compliance path whereby 30 percent of vocational vehicles would 

have one or more of the transmission technologies identified above in this chapter applied by 

MY 2021, increasing to nearly 60 percent by MY 2024 and over 80 percent by MY 2027. Most 

of this increase is due to a projected increase in adoption of technologies that represent deep 

driveline integration. The agencies project an adoption rate of 15 percent in MY 2021 and 30 

percent in MY 2024 for of various non-hardware technologies that enable driveline optimization, 

including gear efficiencies, shift strategies, and torque converter lockups. Manufacturers would 

use the powertrain test to certify these technology improvements. Due to the relatively high 

efficiency gains available from driveline optimization for relatively low costs, the agencies are
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projecting a 70 percent application rate of driveline optimization (including the non-hardware 

enabling technologies) by MY 2027 across all subcategories. We do not have information about 

the extent to which integration may be deterred by barriers to information-sharing between 

component suppliers. Therefore we are projecting that major manufacturers would work to 

overcome these barriers, integrate and optimize their drivelines, and use the powertrain test on all 

eligible configurations, while smaller manufacturers may not adopt these technologies at all, or 

not to a degree that they would find value in this optional test procedure.

For the technology of adding two gears, we are predicating the proposed MY 2021 

standard on a five percent adoption rate, except for zero in the HHD Regional subcategory, 

which is modeled with a 10-speed transmission. This adoption rate is projected to essentially 

remain at this level throughout the program, with an increase to ten percent only for two 

subcategories (Regional LHD and MHD) in MY 2027. This is because the manufacturers most 

likely to develop 8-speed transmissions are those that are also developing transmissions for HD 

pickups and vans, and the GEM-certified vocational market share among those manufacturers is 

relatively small. 

The HHD Regional subcategory is the only one where we assume a manual transmission

in the baseline configuration. For these vehicles, the agencies project upgrades to electronic 

transmissions such as either AMT, DCT, or automatic, at collective adoption rates of 51 percent

in MY 2021, 68 percent in MY 2024, and five percent in MY 2027. The decrease in MY 2027 

reflects a projection that a greater number of deeply integrated HHD powertrains would be used 

by MY 2027 (one consequence being that fewer HHD powertrains would be directly simulated 

in GEM in that year). The larger numbers in the phase-in years reflect powertrains that have 

been automated or electrified but not deeply integrated. The agencies have been careful to 

account for the cost of both electrifying and deeply integrating the MY 2027 powertrains. In 

draft RIA Chapter 11, the technology adoption rates for the HHD Regional subcategory

presented in Table 11-42, Table 11-45, and Table 11-48 account for the assumption that a 

manual transmission cannot be deeply integrated, so there must also be an automation upgrade. 

These tables are inputs to the agencies’ cost analysis, thus the costs of both upgrading and 

integrating HHD powertrains are included. The adoption rates of the upgraded but not integrated 

transmission architectures represent a projection of three percent of all vocational vehicles in 

MY 2021 and four percent in MY 2024. This is based on an estimate that seven percent of the 

vocational vehicles would be in the HHD Regional subcategory. For more information about the 

assumptions that were made about the populations of vehicles in different subcategories, see the 

agencies’ inventory estimates in draft RIA Chapter 5. 

In the eight subcategories in which automatic transmissions are the base technology, the 

agencies project that five percent would upgrade to a dual clutch transmission in MY 2021. This 

projection increases to 15 percent in MY 2024 and decreases in MY 2027 to ten percent for two 

subcategories (Regional LHD and MHD) and five percent for the remaining 6 subcategories. 

The low projected adoption rates of DCT reflect the fact that this is a relatively new technology

for the heavy-duty sector, and it is likely that broader market acceptance would be achieved once 

fleets have gained experience with the technology. Similar to the pattern described for the HHD 

Regional subcategory, the decrease in MY 2027 reflects a projection of greater use of deeply 

integrated powertrains.
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In determining the proposed standard stringency, we have projected that hybrids on 

vehicles certified in the Multipurpose subcategories would achieve on average 22 percent 

improvement, and those in the Urban subcategories would see a 25 percent improvement. We 

have also projected zero hybrid adoption rate by vehicles in the Regional subcategories, 

expecting that the benefit of hybrids for those vehicles would be too low to merit use of that type 

of technology. However, there is no fixed hybrid value assigned in GEM and the actual 

improvement over the applicable test cycle would be determined by powertrain testing. By the 

full implementation year of MY 2027, the agencies are projecting an overall vocational vehicle 

adoption rate of ten percent hybrids, which we estimate would be 18 percent of vehicles certified 

in the Multi-Purpose and Urban subcategories. We are projecting a low adoption rate in the 

early years of the Phase 2 program, just four percent in these subcategories in MY 2021, and 

seven percent in MY 2024 for vehicles certified in the Multi-Purpose and Urban subcategories. 

Based on our assumptions about the populations of vehicles in different subcategories, these 

hybrid adoption rates are about two percent overall in MY 2021 and four percent overall in MY 

2024.

Considering the combination of the above technologies and adoption rates, we project the 

CO2 and fuel efficiency improvements for all transmission upgrades to be approximately seven

percent on a fleet basis by MY 2027. One subcategory in which we are projecting a very large 

advanced transmission adoption rate is the HHD Regional subcategory, in which we are 

projecting 75 percent of the transmissions would be either automated or automatic (upgraded 

from a manual) with 70 percent of those also being deeply integrated by MY 2027. By

comparison, the agencies are projecting that HHD day cab tractors would have 90 percent 

adoption of automated or automatic transmissions by MY 2027. Although we are not prepared 

to predict what fraction of these would be upgraded in the absence of Phase 2, as noted above in 

Chapter 2.9.3, the agencies are confident that durable transmissions will be widely available in 

the Phase 2 time frame to support manufacture of HHD vocational vehicles.

If the above technologies do not reach the expected level of market adoption, the 

vocational vehicle Phase 2 program has several other technology options that manufacturers 

could choose to meet the proposed standards.

2.9.5.1.2 Axles

The agencies project that 75 percent of vocational vehicles in all subcategories would 

adopt advanced axle lubricant formulations in all implementation years of the Phase 2 program.

Fuel efficient lubricant formulations are widespread across the heavy-duty market, though 

advanced synthetic formulations are currently less popular.N Axle lubricants with improved 

viscosity and efficiency-enhancing performance are projected to be widely adopted by 

manufacturers in the time frame of Phase 2. Such formulations are commercially available and 

the agencies see no reason why they could not be feasible for most vehicles. Nonetheless, we 

have refrained from projecting full adoption of this technology. The agencies do not have 

specific information regarding reasons why axle manufacturers may specify a specific type of 

 

N

 Based on conversations with axle suppliers.
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lubricant over another, and whether advanced lubricant formulations may not be recommended 

in all cases. 

The agencies estimate that 45 percent of HHD Regional vocational vehicles would adopt 

either full time or part time 6x2 axle technology in MY 2021. This technology is most likely to 

be applied to Class 8 vocational vehicles (with 2 rear axles) that are designed for frequent 

highway trips. The agencies project a slightly higher adoption rate of 60 percent combined for 

both full and part time 6x2 axle technologies in MY 2024 and MY 2027. Based on our estimates 

of vehicle populations, this is about four percent of all vocational vehicles.

2.9.5.1.3 Lower Rolling Resistance Tires

The agencies estimate that the per-vehicle average level of rolling resistance from 

vocational vehicle tires could be reduced by 11 percent by full implementation of the Phase 2 

program in MY 2027, based on the tire development achievements expected over the next 

decade. This is estimated by weighting the projected improvements of steer tires and drive tires 

using an assumed axle load distribution of 30 percent on the steer tires and 70 percent on the 

drive tires, as explained in the draft RIA Chapter 2.9. By applying the assumed axle load 

distribution, the average vehicle CRR improvements projected for the proposed MY 2021 

standards would be four percent, which we project would achieve up to one percent reduction in 

fuel use and CO2 emissions, depending on the vehicle subcategory. Using that same method, the 

agencies estimate the average vehicle CRR in MY 2024 would be seven percent, yielding 

reductions in fuel use and CO2 emissions of between one and two percent, depending on the 

vehicle subcategory. 

The agencies understand that the vocational vehicle segment has access to a large variety 

of tires, including some that are designed for tractors, some that are designed for HD pickups and 

vans, and some with multiple use designations. In spite of the likely availability of LRR tires 

during the Phase 2 program, the projected adoption rates are intended to be conservative. The 

agencies believe that these tire packages recognize the variety of tire purposes and performance 

levels in the vocational vehicle market, and maintain choices for manufacturers to use the most 

efficient tires (i.e. those with least rolling resistance) only where it makes sense given these 

vehicles’ differing purposes and applications. The projected adoption rates and expected 

improvements in CRR are presented in Table 2-54.

Table 2-54 Projected LRR Tire Adoption Rates

TIRE 

POSITION

LEVEL OF ROLLING 

RESISTANCE

MY 2021 

ADOPTION RATE

MY 2024 

ADOPTION RATE

MY 2027 

ADOPTION 

RATE

Drive Baseline CRR (7.7) 50 20 10

Steer Baseline CRR (7.7) 20 10 0

Drive 5% Lower CRR (7.3) 50 50 25

Steer 10% Lower CRR (6.9) 80 30 20

Drive 10% Lower CRR (6.9) 0 30 50

Steer 15% Lower CRR (6.5) 0 60 30

Drive 15% Lower CRR (6.5) 0 0 15

Steer 20% Lower CRR (6.2) 0 0 50
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Drive Average Improvement 

in CRR

3% 6% 9%

Steer Average Improvement 

in CRR

8% 12% 17%

For comparison purposes, the reader may note that these levels of tire CRR generally 

correspond with levels of tire CRR projected for tractors built for the Phase 1 standards. For 

example, the baseline level CRR for vocational tires is very similar to the baseline tractor steer 

tire CRR. Vocational vehicle tires with 10 percent better CRR have a similar CRR level as 

tractor tires of Drive Level 1. Vocational vehicle tires with 15 percent better CRR have a similar 

CRR level as tractor tires of Steer Level 1. Vocational vehicle tires with 20 percent better CRR 

have a similar CRR level as tractor tires of Drive Level 2, as described in preamble Section 

III.D.2.

2.9.5.1.4 Workday Idle Reduction

In this proposal, we are projecting a progression of idle reduction technology

development that begins with 70 percent adoption rate of neutral idle for the MY 2021 standards, 

which by MY 2027 is replaced by a 70 percent adoption rate of stop-start idle reduction 

technology. Although it is possible that a vehicle could have both neutral idle and stop-start, we 

are only considering emissions reductions for vehicles with one or the other of these 

technologies. Also, as the program phases in, we do not see a reduction in the projected adoption 

rate of neutral idle to be a concern in terms of stranded investment, because it is a very low cost 

technology that could be an enabler for stop-start systems in some cases. 

We are not projecting any adoption of neutral idle for the HHD Regional subcategory,

because any vehicle with a manual transmission must shift to neutral when stopped to avoid 

stalling the engine, vehicles in the HHD Regional subcategory would already essentially be 

idling in neutral, and no additional technology would be needed to achieve this. A similar case 

can be made for any vocational vehicle with an automated manual transmission, since these 

share inherently similar architectures with manual transmissions. The agencies are not 

projecting an adoption rate of 85 percent neutral idle until MY 2024, because it may take some 

additional development time to apply this technology to high-torque automatic transmissions 

designed for the largest vocational vehicles. Based on stakeholder input, the designs needed to 

avoid an uncomfortable re-engagement bump when returning to drive from neutral may require 

some engineering development time as well as some work to enable two-way communication 

between engines and transmissions.

We are projecting a five percent adoption rate of stop-start in the six MHD and LHD 

subcategories for MY 2021 and zero for the HHD vehicles, because this technology is still 

developing for vocational vehicles and is most likely to be feasible in the early years of Phase 2 

for vehicles with lower power demands and lower engine inertia. Stopping a heavy-duty engine 

is not challenging. The real challenge is designing a robust system that can deliver multiple 

smooth restarts daily without loss of function while the engine is off. Many current light-duty 

products offer this feature, and some heavy-duty manufacturers are exploring this.146 The 

agencies are projecting an adoption rate of 15 percent stop-start across all subcategories in the 

intermediate year of MY 2024. The agencies are projecting this technology to have a relatively 
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high adoption rate (70 percent as stated above) by MY 2027 because we see it being technically

feasible on the majority of vocational vehicles, and especially effective on those with the most 

time at idle in their workday operation. Although we are not prepared to predict what fraction of 

vehicles would adopt stop-start in the absence of Phase 2, above in draft RIA Chapter 2.9.3 the 

agencies explain why we are confident that this technology, which is on the entry-level side of 

the hybrid and electrification spectrum, will be widely available in the Phase 2 time frame. 

Based on these projected adoption rates and the effectiveness values described above in 

this section, we expect overall GHG and fuel consumption reductions from workday idle on 

vocational vehicles to be approximately three percent in MY 2027.

2.9.5.1.5 Weight Reduction

As described in the draft RIA Chapter 2.12, weight reduction is a relatively costly

technology, at approximately $3 to $4 per pound for a 200-lb package. Even so, for vehicles in 

service classes where dense, heavy loads are frequently carried, weight reduction can translate 

directly to additional payload. The agencies project weight reduction would most likely be used 

for vocational vehicles in the refuse and construction service classes, as well as some regional 

delivery vehicles. The agencies are predicating the proposed standards on an adoption rate of 

five to eight percent, depending on the subcategory, in MY 2027, with slightly lower adoption 

rates in MY 2021 and MY 2024.

For this technology package, NHTSA and EPA project manufacturers would use material 

substitution in the amount of 200 pounds. An example of how this weight could be reduced 

would be a complete set of aluminum wheels for a Class 8 vocational vehicle, or an aluminum 

transmission case plus high strength steel wheels, frame rails, and suspension brackets on a 

MHD or LHD vocational vehicle. The agencies have limited information about how popular the 

use of aluminum components is in the vocational vehicle sector.

2.9.5.1.6 HFC Leakage

We project 100 percent adoption rate in all implementation years of the Phase 2 program

for use of low leakage air conditioning system components to reduce direct emissions of HFC 

compounds from vocational vehicles.

2.9.5.2 Proposed Vocational Vehicle Standards

The agencies applied the technology adoption rates shown in Table 2-55 through Table 

2-57 as GEM inputs, but have not directly transferred the GEM results from these inputs as the 

proposed standards. Rather, the proposed standards are the result of the normalizing process

described in Chapter 2.9.2.1. The proposed standards are presented in Table 2-58 through Table 

2-63.
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Table 2-55 GEM Inputs Used to Derive Proposed MY 2021 Vocational Vehicle Standards

CLASS 2B-5 CLASS 6-7 CLASS 8

Urban MultiPurposeRegional Urban MultiPurposeRegional Urban MultiPurposeRegional

CI Enginea

2021 MY 7L, 200 hp Engine 2021 MY 7L, 270 hp Engine 2021 MY 11L, 345 

hp Engine

2021 MY 

15L 455hp 

Engine

Transmission (improvement factor)

0.023 0.021 0.008 0.023 0.021 0.009 0.023 0.022 0.022

Axle (improvement factor)

0.004 0.004 0.004 0.004 0.004 0.004 0.004 0.004 0.012

Stop-Start (adoption rate)

5% 5% 5% 5% 5% 5% 0% 0% 0%

Neutral Idle (adoption rate)

70% 70% 70% 70% 70% 70% 70% 70% 0%

Steer Tires (CRR kg/metric ton)

7.1 7.1 7.1 7.1 7.1 7.1 7.1 7.1 7.1

Drive Tires (CRR kg/metric ton)

7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5

Weight Reduction (lb)

8 8 14 8 8 12 8 8 10

Note:

a

SI engines were not simulated in GEM, rather a gas/diesel adjustment factor was applied to the results

Table 2-56 GEM Inputs Used to Derive Proposed MY 2024 Vocational Vehicle Standards

CLASS 2B-5 CLASS 6-7 CLASS 8

Urban MultiPurposeRegional Urban MultiPurposeRegional Urban MultiPurposeRegional

CI Enginea

2024 MY 7L, 200 hp Engine 2024 MY 7L, 270 hp Engine 2024 MY 11L, 345 

hp Engine

2024 MY 

15L 455hp 

Engine

Transmission (improvement factor)

0.045 0.04 0.017 0.045 0.041 0.018 0.045 0.042 0.035

Axle (improvement factor)

0.004 0.004 0.004 0.004 0.004 0.004 0.004 0.004 0.014

Stop-Start (adoption rate)

15% 15% 15% 15% 15% 15% 15% 15% 15%

Neutral Idle (adoption rate)

85% 85% 85% 85% 85% 85% 85% 85% 0%

Steer Tires (CRR kg/metric ton)

6.8 6.8 6.8 6.8 6.8 6.8 6.8 6.8 6.8

Drive Tires (CRR kg/metric ton)

7.3 7.3 7.3 7.3 7.3 7.3 7.3 7.3 7.3

Weight Reduction (lb)
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8 8 14 8 8 12 8 8 10

Note:

a

SI engines were not simulated in GEM, rather a gas/diesel adjustment factor was applied to the results

Table 2-57 GEM Inputs Used to Derive Proposed MY 2027 Vocational Vehicle Standards

CLASS 2B-5 CLASS 6-7 CLASS 8

Urban MultiPurposeRegional Urban MultiPurposeRegional Urban MultiPurposeRegional

CI Enginea

2027 MY 7L, 200 hp Engine 2027 MY 7L, 270 hp Engine 2027 MY 11L, 345 

hp Engine

2027 MY 

15L 455hp 

Engine

Transmission (improvement factor)

0.096 0.085 0.034 0.096 0.088 0.037 0.097 0.089 0.036

Axle (improvement factor)

0.004 0.004 0.004 0.004 0.004 0.004 0.004 0.004 0.014

Stop-Start (adoption rate)

75% 70% 70% 75% 70% 70% 70% 70% 70%

Neutral Idle (adoption rate)

25% 30% 30% 25% 30% 30% 30% 30% 0%

Steer Tires (CRR kg/metric ton)

6.4 6.4 6.4 6.4 6.4 6.4 6.4 6.4 6.4

Drive Tires (CRR kg/metric ton)

7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0

Weight Reduction (lb)

10 10 16 10 10 14 10 10 12

Note:

a

SI engines were not simulated in GEM, rather a gas/diesel adjustment factor was applied to the results

Table 2-58 and Table 2-59 present EPA’s proposed CO2 standards and NHTSA’s 

proposed fuel consumption standards, respectively, for chassis manufacturers of Class 2b 

through Class 8 vocational vehicles for the beginning model year of the program, MY 2021. As 

in Phase 1, the standards would be in the form of the mass of emissions, or gallons of fuel, 

associated with carrying a ton of cargo over a fixed distance. The EPA standards would be 

measured in units of grams CO2 per ton-mile and the NHTSA standards would be in gallons of 

fuel per 1,000 ton-miles. With the mass of freight in the denominator of this term, the program 

is designed to measure improved efficiency in terms of freight efficiency. As in Phase 1, the 

Phase 2 program would assign a fixed default payload in GEM for each vehicle weight class 

group (heavy heavy-duty, medium heavy-duty, and light heavy-duty). Even though this 

simplification does not allow individual vehicle freight efficiencies to be recognized, the general 

capacity for larger vehicles to carry more payload is represented in the numerical values of the 

proposed standards for each weight class group.
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Table 2-58 Proposed EPA CO2 Standards for MY2021 Class 2b-8 Vocational Vehicles 

EPA Standard for Vehicle with CI Engine Effective MY2021 (gram CO2/ton-mile)

Duty Cycle Light Heavy-Duty 

Class 2b-5

Medium Heavy-Duty 

Class 6-7

Heavy Heavy-Duty

Class 8

Urban 296 188 198

Multi-Purpose 305 190 200

Regional 318 186 189

EPA Standard for Vehicle with SI Engine Effective MY2021 (gram CO2/ton-mile)

Duty Cycle Light Heavy-Duty 

Class 2b-5

Medium Heavy-Duty 

Class 6-7

Heavy Heavy-Duty

Class 8

Urban 320 203 214

Multi-Purpose 329 205 216

Regional 343 201 204

Table 2-59 Proposed NHTSA Fuel Consumption Standards for MY2021 Class 2b-8 Vocational Vehicles 

NHTSA Standard for Vehicle with CI Engine Effective MY 2021 (Fuel Consumption 

gallon per 1,000 ton-mile)

Duty Cycle Light Heavy-Duty 

Class 2b-5

Medium Heavy-Duty 

Class 6-7

Heavy Heavy-Duty

Class 8

Urban 29.0766 18.4676 19.4499

Multi-Purpose 29.9607 18.6640 19.6464

Regional 31.2377 18.2711 18.5658

NHTSA Standard for Vehicle with SI Engine Effective MY 2021 (Fuel Consumption 

gallon per 1,000 ton-mile) 

Duty Cycle Light Heavy-Duty 

Class 2b-5

Medium Heavy-Duty 

Class 6-7

Heavy Heavy-Duty

Class 8

Urban 36.0077 22.8424 24.0801

Multi-Purpose 37.0204 23.0674 24.3052

Regional 38.5957 22.6173 22.9549

EPA’s proposed vocational vehicle CO2 standards and NHTSA’s proposed fuel 

consumption standards for the MY 2024 stage of the program are presented in Table 2-60 and 

Table 2-61, respectively. These reflect broader adoption rates of vehicle technologies already 

considered in the technology basis for the MY 2021 standards. The standards for vehicles 

powered by CI engines also reflect that in MY 2024, the separate engine standard would be more 

stringent, so the vehicle standard keeps pace with the engine standard.
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Table 2-60 Proposed EPA CO2 Standards for MY2024 Class 2b-8 Vocational Vehicles

EPA Standard for Vehicle with CI Engine Effective MY2024 (gram CO2/ton-mile)

Duty Cycle Light Heavy-Duty 

Class 2b-5

Medium Heavy-Duty 

Class 6-7

Heavy Heavy-Duty

Class 8

Urban 284 179 190

Multi-Purpose 292 181 192

Regional 304 178 182

EPA Standard for Vehicle with SI Engine Effective MY2024 (gram CO2/ton-mile)

Duty Cycle Light Heavy-Duty 

Class 2b-5

Medium Heavy-Duty 

Class 6-7

Heavy Heavy-Duty

Class 8

Urban 312 197 208

Multi-Purpose 321 199 210

Regional 334 196 199

Table 2-61 Proposed NHTSA Fuel Consumption Standards for MY2024 Class 2b-8 Vocational Vehicles

NHTSA Standard for Vehicle with CI Engine Effective MY 2024 (Fuel Consumption 

gallon per 1,000 ton-mile)

Duty Cycle Light Heavy-Duty 

Class 2b-5

Medium Heavy-Duty 

Class 6-7

Heavy Heavy-Duty

Class 8

Urban 27.8978 17.5835 18.6640

Multi-Purpose 28.6837 17.7800 18.8605

Regional 29.8625 17.4853 17.8782

NHTSA Standard for Vehicle with SI Engine Effective MY 2024 (Fuel Consumption 

gallon per 1,000 ton-mile)

Duty Cycle Light Heavy-Duty 

Class 2b-5

Medium Heavy-Duty 

Class 6-7

Heavy Heavy-Duty

Class 8

Urban 35.1075 22.1672 23.4050

Multi-Purpose 36.1202 22.3923 23.6300

Regional 37.5830 22.0547 22.3923

EPA’s proposed vocational vehicle CO2 standards and NHTSA’s proposed fuel 

consumption standards for the full implementation year of MY 2027 are presented in Table 2-62

and Table 2-63, respectively. These reflect even greater adoption rates of the same vehicle 

technologies considered in the basis for the previous stages of the Phase 2 standards. The 

proposed MY 2027 standards for vocational vehicles powered by CI engines reflect additional 

engine technologies consistent with those on which the separate proposed MY 2027 CI engine 

standard is based. The proposed MY 2027 standards for vocational vehicles powered by SI

engines reflect improvements due to additional engine friction reduction technology, which is 

not among the technologies on which the separate SI engine standard is based.
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Table 2-62 Proposed EPA CO2 Standards for MY2027 Class 2b-8 Vocational Vehicles

EPA Standard for Vehicle With CI Engine Effective MY2027 (gram CO2/ton-mile)

Duty Cycle Light Heavy-Duty 

Class 2b-5

Medium Heavy-Duty 

Class 6-7

Heavy Heavy-Duty

Class 8

Urban 272 172 182

Multi-Purpose 280 174 183

Regional 292 170 174

EPA Standard for Vehicle with SI Engine Effective MY2027 (gram CO2/ton-mile)

Duty Cycle Light Heavy-Duty 

Class 2b-5

Medium Heavy-Duty 

Class 6-7

Heavy Heavy-Duty

Class 8

Urban 299 189 196

Multi-Purpose 308 191 198

Regional 321 187 188

Table 2-63 Proposed NHTSA Fuel Consumption Standards for MY2027 Class 2b-8 Vocational Vehicles

NHTSA Standard For Vehicle With CI Engine Effective MY 2027 (Fuel Consumption 

Gallon per 1,000 ton-mile)

Duty Cycle Light Heavy-Duty 

Class 2b-5

Medium Heavy-Duty 

Class 6-7

Heavy Heavy-Duty

Class 8

Urban 26.7191 16.8959 17.8782

Multi-Purpose 27.5049 17.0923 17.9764

Regional 28.6837 16.6994 17.0923

NHTSA Standard for Vehicle with SI Engine Effective MY 2027 (Fuel Consumption 

gallon per 1,000 ton-mile)

Duty Cycle Light Heavy-Duty 

Class 2b-5

Medium Heavy-Duty 

Class 6-7

Heavy Heavy-Duty

Class 8

Urban 33.6446 21.2670 22.0547

Multi-Purpose 34.6574 21.4921 22.2797

Regional 36.1202 21.0420 21.1545

2.9.5.3 Summary of Vocational Vehicle Package Costs

The agencies have estimated the costs of the technologies expected to be used to comply

with the proposed standards. Table 2-64 presents estimated incremental costs for MY2021 for 

light, medium and heavy HD vocational vehicles in each duty-cycle-based subcategory – Urban, 

Multi-Purpose, and Regional. As shown, in MY 2021 these range from approximately $600 for 

MHD and LHD Regional vehicles, up to $3,400 for HHD Regional vehicles. Those two lowercost packages reflect zero hybrids, and the higher-cost package reflects significant adoption of 

automated transmissions. In the draft RIA Chapter 2.13, the agencies present vocational vehicle 
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technology package costs differentiated by MOVES vehicle type. For example, in Table 2-231, 

intercity buses are estimated to have an average package cost of $2,900 and gasoline motor 

homes are estimated to have an average package cost of $450 in MY 2021. These costs do not 

indicate the per-vehicle cost that may be incurred for any individual technology. Chapter 2.12.7 

describes why a complex technology such as hybridization is estimated to range between 

$15,000 and $40,000 per vehicle for vocational vehicles in MY 2021. The engine costs listed 

represent the cost of an average package of diesel engine technologies. Individual technology

adoption rates for engine packages are described above in Chapter 2.7. The details behind these 

costs are presented in draft RIA Chapter 2.12, including the markups and learning effects applied 

and how the costs shown here are weighted to generate an overall cost for the vocational sector.

Table 2-64 Technology Package Incremental Costs for Vocational Vehicles for MY2021a,b (2012$)

LIGHT HD MEDIUM HD HEAVY HD

Urban MultipurposeRegional Urban MultipurposeRegional Urban MultipurposeRegional

Enginec$293 $293 $293 $270 $270 $270 $270 $270 $270

Tires $7 $7 $7 $7 $7 $7 $7 $7 $7

Transmission $81 $81 $81 $81 $81 $81 $81 $81 $2,852

Axle related $99 $99 $99 $99 $99 $99 $148 $148 $219

Weight 

Reduction

$27 $27 $48 $27 $27 $41 $27 $27 $34

Idle reduction $49 $49 $49 $51 $51 $51 $6 $6 $0

Electrification 

& hybridization

$547 $547 $0 $861 $861 $0 $1,437 $1,437 $0

Air 

Conditioning

$22 $22 $22 $22 $22 $22 $22 $22 $22

Total $1,125 $1,125 $598 $1,418 $1,418 $571 $1,998 $1,998 $3,404

Notes:

a Costs shown are for the 2021 model year and are incremental to the costs of a vehicle meeting the Phase 1 

standards. These costs include indirect costs via markups along with learning impacts. For a description of the 

markups and learning impacts considered in this analysis and how it impacts technology costs for other years, refer 

to draft RIA Chapter 2.12.

b Note that values in this table include adoption rates. Therefore, the technology costs shown reflect the average cost 

expected for each of the indicated vehicle subcategories. 

c Engine costs shown are for a light HD, medium HD or heavy HD diesel engines. For gasoline-powered vocational 

vehicles we are projecting no additional engine-based costs beyond Phase 1.

Table 2-65 presents estimated incremental costs for MY2024 for light, medium and 

heavy HD vocational vehicles in each duty-cycle-based subcategory – Urban, Multi-Purpose, 

and Regional. As shown, these range from approximately $800 for MHD and LHD Regional 

vehicles, up to $4,800 for HHD Regional vehicles. The increased costs above the MY 2021 

values reflect increased adoption rates of individual technologies, while the individual 

technology costs are generally expected to remain the same or decrease, as explained in the draft 

RIA Chapter 2.12. For example, Chapter 2.12.7 presents MY 2024 hybridization costs that 

range from $13,000 to $33,000 per vehicle for vocational vehicles. 
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Table 2-65 Technology Package Incremental Costs for Vocational Vehicles for MY2024a,b (2012$)

LIGHT HD MEDIUM HD HEAVY HD

Urban MultipurposeRegional Urban MultipurposeRegional Urban MultipurposeRegional

Enginec$437 $437 $437 $405 $405 $405 $405 $405 $405

Tires $17 $17 $17 $17 $17 $17 $23 $23 $23

Transmission $123 $123 $123 $123 $123 $123 $123 $123 $3,915

Axle related $90 $90 $90 $90 $90 $90 $136 $136 $224

Weight Reduction $24 $24 $43 $24 $24 $37 $24 $24 $30

Idle reduction $119 $119 $119 $125 $125 $125 $224 $224 $217

Electrification & 

hybridization

$906 $906 $0 $1,423 $1,423 $0 $2,377 $2,377 $0

Air Conditioning $20 $20 $20 $20 $20 $20 $20 $20 $20

Total $1,737 $1,737 $849 $2,228 $2,228 $817 $3,332 $3,332 $4,834

Notes:

a Costs shown are for the 2024 model year and are incremental to the costs of a vehicle meeting the Phase 1 

standards. These costs include indirect costs via markups along with learning impacts. For a description of the 

markups and learning impacts considered in this analysis and how it impacts technology costs for other years, refer 

to draft RIA Chapter 2.12.

b Note that values in this table include adoption rates. Therefore, the technology costs shown reflect the average cost 

expected for each of the indicated vehicle subcategories.

c Engine costs shown are for a light HD, medium HD or heavy HD diesel engines. For gasoline-powered vocational 

vehicles we are projecting no additional engine-based costs beyond Phase 1.

Table 2-66 presents estimated incremental costs for MY2027 for light, medium and 

heavy HD vocational vehicles in each duty-cycle-based subcategory – Urban, Multi-Purpose, 

and Regional. As shown, these range from approximately $1,400 for MHD and LHD Regional 

vehicles, up to $7,400 for HHD Urban and Multipurpose vehicles. These two subcategories are 

projected to have the higher-cost packages in MY 2027 due to an estimated 18 percent adoption 

of HHD hybrids, which are estimated to cost $31,000 per vehicle in MY 2027, as shown in 

Chapter 2.12.7 of the draft RIA. The engine costs shown represent the average costs associated 

with the proposed MY 2027 vocational diesel engine standard described in Section II.D. For 

gasoline vocational vehicles, the agencies are projecting adoption of Level 2 engine friction 

reduction with an estimated $68 added to the average SI vocational vehicle package cost in MY 

2027, which represents about 56 percent of those vehicles upgrading beyond Level 1 engine 

friction reduction. Further details on how these SI vocational vehicle costs were estimated are 

provided above in Chapter 2.9.1.
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Table 2-66 Technology Package Incremental Costs for Vocational Vehicles for MY2027a,b (2012$)

LIGHT HD MEDIUM HD HEAVY HD

Urban MultipurposeRegional Urban MultipurposeRegional Urban MultipurposeRegional

Enginec$471 $471 $471 $437 $437 $437 $437 $437 $437

Tires $20 $20 $20 $20 $20 $20 $29 $29 $29

Transmission $244 $244 $267 $244 $244 $267 $244 $244 $2,986

Axle related $86 $86 $86 $86 $86 $86 $129 $129 $215

Weight Reduction $29 $29 $46 $29 $29 $40 $29 $29 $35

Idle reduction $498 $499 $499 $526 $526 $526 $964 $964 $962

Electrification & 

hybridization

$2,122 $2,122 $0 $3,336 $3,336 $0 $5,571 $5,571 $0

Air Conditioning $19 $19 $19 $19 $19 $19 $19 $19 $19

Total $3,489 $3,490 $1,407 $4,696 $4,696 $1,395 $7,422 $7,422 $4,682

Notes:

a Costs shown are for the 2024 model year and are incremental to the costs of a vehicle meeting the Phase 1 

standards. These costs include indirect costs via markups along with learning impacts. For a description of the 

markups and learning impacts considered in this analysis and how it impacts technology costs for other years, refer 

to draft RIA Chapter 2.12.

b Note that values in this table include adoption rates. Therefore, the technology costs shown reflect the average cost 

expected for each of the indicated vehicle subcategories.

c Engine costs shown are for a light HD, medium HD or heavy HD diesel engines. For gasoline-powered vocational 

vehicles we are projecting $68 of additional engine-based costs beyond Phase 1.

2.9.6 Technologies and Costs of Alternative 4

2.9.6.1 Derivation of Alternative 4 Standards

2.9.6.1.1 Adoption Rates

In developing the Alternative 4 standards, the agencies are projecting a set of technology

packages in MY 2024 that is identical to those projected for the final phase-in year of the 

preferred alternative. In the package descriptions below, the agencies outline technologyspecific adoption rates in MY 2021 for Alternative 4 and offer insights on what market 

conditions could enable reaching adoption rates that would achieve the full implementation 

levels of stringency with less lead time. 

For transmissions including hybrids, the agencies project for Alternative 4 that 50 percent 

of vocational vehicles would have one or more of the transmission technologies identified above 

in this Section applied by MY 2021. This includes 25 percent deeply integrated conventional 

transmissions that would be recognized over the powertrain test, 10 percent DCT, 11 percent 

adding two gears (except zero for HHD Regional), and nine percent hybrids for vehicles certified 

in the Multi-Purpose and Urban subcategories, which we estimate would be five percent overall. 

In this alternative, the agencies project 21 percent of the vocational vehicles with manual 

transmissions in the HHD Regional subcategory would upgrade to either an AMT, DCT, or 

automatic transmission. The increased projection of driveline integration would mean that more 

manufacturers would need to overcome data-sharing barriers. In this alternative, we project that 

manufacturers would need to conduct additional research and development to achieve overall 

application of five percent hybrids. In the draft RIA Chapter 7.1, the agencies have estimated 
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costs for this additional accelerated research. In the preamble at Section V, the agencies request 

comment on the expected costs to accelerate hybrid development to meet the projected adoption 

rates of this alternative.

For advanced axle lubricants, the agencies are projecting the same 75 percent adoption 

rate in MY 2021 as in the proposed program. For part time or full time 6x2 axles, the agencies 

project the HHD Regional vocational vehicles could apply this at the 60 percent adoption rate in 

MY 2021, where this level wouldn’t be reached until MY 2024 in the proposed program. One 

action that could enable this to be achieved is if information on the reliability of these systems 

were to be disseminated to more fleet owners by trustworthy sources.

For lower rolling resistance tires in this alternative, the agencies project the same 

adoption rates of LRR tires as in the proposed program for MY 2021, because we don’t expect 

tire suppliers would be able to make greater improvements for the models that are fitted on 

vocational vehicles in that time frame. The tire research that is being conducted currently is 

focused on models for tractors and trailers, and we project further improved LRR tires would not 

be commercially available for vocational vehicles in the early implementation years of Phase 2.

For the adoption rate of LRR tires in MY 2024 to reach the level projected for MY 2027 

in the proposed program, tire suppliers could promote their most efficient products to vocational 

vehicle manufacturers to achieve equivalent improvements with less lead time. Depending on 

how tire manufacturers focus their research and product development, it is possible that more of 

the LRR tire advancements being applied for tractors and trailers could be applied to vocational 

vehicles. To see the specific projected adoption rates of different levels of LRR tires for 

Alternative 4, see columns three and five of Table 2-54 above.

For workday idle technologies, the agencies project an adoption rate of 12 percent stopstart in the six MHD and LHD subcategories for MY 2021 and zero for the HHD vehicles, on the 

expectation that manufacturers would have fewer challenges in the short term in bringing this 

technology to market for vehicles with lower power demands and lower engine inertia. In this 

alternative, the agencies project the overall workday idle adoption rate would approach 100 

percent, such that any vehicle without stop-start (except HHD Regional) would apply neutral idle 

in MY 2021. These adoption raters consider a more aggressive investment by manufacturers in 

developing these technologies. Estimates of research and development costs for this alternative 

are presented in the draft RIA Chapter 7.1.

For weight reduction, in this alternative, the agencies project the same adoption rates of a 

200-lb lightweighting package as in the proposal for each subcategory in MY 2021, which is four 

to seven percent.

2.9.6.1.2 Costs Associated with Alternative 4 Standards

The agencies have estimated the costs of the technologies expected to be used to comply

with the Alternative 4 standards, as shown in Table 2-67 for MY2021. Fleet average costs are 

shown for light, medium and heavy HD vocational vehicles in each duty-cycle-based 

subcategory – Urban, Multi-Purpose, and Regional. As shown, in MY 2021 these range from 

approximately $800 for MHD and LHD Regional vehicles, to $4,300 for HHD Urban and 
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Multipurpose vehicles. Those two subcategories are projected to have the higher-cost packages 

in MY 2021 due to an estimated 9 percent adoption of HHD hybrids, which are estimated to cost 

$40,000 per vehicle in MY 2021, as shown in Chapter 2.12.7 of the draft RIA. The engine costs 

listed represent the cost of an average package of diesel engine technologies with Alternative 4 

adoption rates described in the preamble at Section II.D.2(e).

Table 2-67 Vocational Vehicle Technology Incremental Costs for Alternative 4Standards in the 2021 Model 

Yeara,b (2012$)

LIGHT HD MEDIUM HD HEAVY HD

Urban MultipurposeRegional Urban MultipurposeRegional Urban MultipurposeRegional

Enginec$372 $372 $372 $345 $345 $345 $345 $345 $345

Tires $7 $7 $7 $7 $7 $7 $7 $7 $7

Transmission $148 $148 $148 $148 $148 $148 $148 $148 $2,042

Axle related $99 $99 $99 $99 $99 $99 $148 $148 $243

Weight 

Reduction

$27 $27 $48 $27 $27 $41 $27 $27 $34

Idle reduction $110 $110 $110 $116 $116 $116 $8 $8 $0

Electrification 

& 

hybridization

$1,384 $1,384 $0 $2,175 $2,175 $0 $3,633 $3,633 $0

Air 

Conditioning

$22 $22 $22 $22 $22 $22 $22 $22 $22

Total $2,169 $2,169 $805 $2,938 $2,938 $777 $4,337 $4,337 $2,693

Notes:

a Costs shown are for the 2021 model year and are incremental to the costs of a vehicle meeting the Phase 1 

standards. These costs include indirect costs via markups along with learning impacts. For a description of the 

markups and learning impacts considered in this analysis and how it impacts technology costs for other years, refer 

to draft RIA Chapter 2.12.

b Note that values in this table include adoption rates. Therefore, the technology costs shown reflect the average cost 

expected for each of the indicated vehicle classes.

c Engine costs are for a light HD, medium HD or heavy HD diesel engine. We are projecting no additional costs 

beyond Phase 1 for gasoline vocational engines in MY2021 under this alternative.

The estimated costs of the technologies expected to be used to comply with the 

Alternative 4 standards for MY2024 are shown in Table 2-68. Fleet average costs are shown for 

light, medium and heavy HD vocational vehicles in each duty-cycle-based subcategory – Urban, 

Multi-Purpose, and Regional. As shown, these range from approximately $1,500 for MHD and 

LHD Regional vehicles to $7,900 for HHD Urban and Multipurpose vehicles. These two 

subcategories are projected to have the higher-cost packages in MY 2024 due to an estimated 18 

percent adoption of HHD hybrids, which are estimated to cost $33,000 per vehicle in MY 2024, 

as shown in Chapter 2.12.7 of the draft RIA. The engine costs listed represent the cost of an 

average package of diesel engine technologies with Alternative 4 adoption rates described in the 

preamble at Section II.D.2(e). For gasoline vocational vehicles, the agencies are projecting 

adoption of Level 2 engine friction reduction with an estimated $74 added to the average SI 

vocational vehicle package cost in MY 2024, which represents about 56 percent of those vehicles 

upgrading beyond Level 1 engine friction reduction. Further details on how these SI vocational 

vehicle costs were estimated are provided above in Chapter 2.9.1. The details behind all these 

costs are presented in draft RIA Chapter 2.12, including the markups and learning effects applied 
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and how the costs shown here are weighted to generate an overall cost for the vocational vehicle 

segment.

Table 2-68 Vocational Vehicle Technology Incremental Costs for Alternative 4 Standards in the 2024 Model 

Yeara,b (2012$)

LIGHT HD MEDIUM HD HEAVY HD

Urban MultipurposeRegional Urban MultipurposeRegional Urban MultipurposeRegional

Enginec

$493 $493 $493 $457 $457 $457 $457 $457 $457

Tires $26 $26 $26 $26 $26 $26 $40 $40 $40

Transmission $256 $256 $280 $256 $256 $280 $256 $256 $3,123

Axle related $90 $90 $90 $90 $90 $90 $136 $136 $224

Weight Reduction $30 $30 $49 $30 $30 $43 $30 $30 $37

Idle reduction $561 $524 $524 $592 $553 $553 $1,014 $1,014 $1,011

Electrification & 

hybridization

$2,264 $2,264 $0 $3,559 $3,559 $0 $5,943 $5,943 $0

Air Conditioning $20 $20 $20 $20 $20 $20 $20 $20 $20

Total $3,741 $3,704 $1,482 $5,030 $4,992 $1,469 $7,895 $7,895 $4,912

Notes:

a Costs shown are for the 2024 model year and are incremental to the costs of a vehicle meeting the Phase 1 

standards. These costs include indirect costs via markups along with learning impacts. For a description of the 

markups and learning impacts considered in this analysis and how it impacts technology costs for other years, refer 

to draft RIA Chapter 2.12.

b Note that values in this table include adoption rates. Therefore, the technology costs shown reflect the average cost 

expected for each of the indicated vehicle subcategories. Estimated technology costs exclusive of adoption rates are 

discussed in RIA 2.12.

c Engine costs shown are for a light HD, medium HD or heavy HD diesel engines. For gasoline-powered vocational 

vehicles we are projecting $74 of additional engine-based costs beyond Phase 1 in MY2024.

2.10 Technology Application and Estimated Costs – Trailers

The agencies are proposing standards for trailers specifically designed to be pulled by 

Class 7 and 8 tractors. These proposed standards are expressed as CO2 and fuel consumption

standards, and would apply to each trailer with respect to the emissions and fuel consumption 

that would be expected for a specific standard type of tractor pulling such a trailer. EPA and 

NHTSA believe it is appropriate to establish standards for trailers separately from tractors 

because they are separately manufactured by distinct companies; the agencies are not aware of 

any manufacturers that currently assemble both the finished tractor and the trailer. This section 

of the draft RIA describes the analyses performed by the agencies as we developed the proposed 

trailer program. 

2.10.1 Trailer Subcategories Evaluated

The agencies evaluated several trailer subcategories for this proposal. Though many of 

the same technologies are available for dry and refrigerated vans, the agencies evaluated these 

trailer types separately. The transport refrigeration unit (TRU) commonly located at the front of 

refrigerated trailers adds weight, has the potential to impact the aerodynamic characteristics of 

the trailer, and may limit the type of aerodynamic devices that can be applied. Additionally, 

“long box” trailers in lengths 50 feet or longer and “short box” trailers less than 50 feet in length 

were evaluated separately due to differences in both weight and use patterns. 
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The agencies identified a list of work-performing devices that are sometimes added to 

standard box trailers, which may inhibit the use of some aerodynamic devices. The agencies are 

proposing to recognize box trailers that are restricted from using aerodynamic devices in one 

location on the trailer as “partial-aero” box trailers. We believe these trailers have the ability to 

adopt some aerodynamic technologies, but do not expect them to be able to meet the same 

stringencies as the standard box vans. 

Additionally, we propose to consider box trailers that have work-performing devices in 

two locations such that they inhibit the use of all practical aerodynamic devices to be “non-aero” 

box trailers that would be not be expected to adopt aerodynamic technologies at any point in the 

program. The agencies are proposing that the non-aero box trailer subcategory include box 

trailers with more than three axles, since they are designed to be used in heavy-haul applications 

where aerodynamic devices are not generally practical. 

The agencies evaluated all non-box highway trailers (e.g., tankers, platforms, and car 

haulers) as a single representative trailer assuming a single stringency level for all trailers within 

the subcategory. These stringency levels did not include the use of aerodynamic technologies. 

In summary, the agencies are proposing ten trailer subcategories:

– Long box (longer than 50 feet) dry vans

– Long box (longer than 50 feet) refrigerated vans

– Short box (50 feet and shorter) dry vans

– Short box (50 feet and shorter) refrigerated vans

– Partial-aero long box dry vans

– Partial-aero long box refrigerated vans

– Partial-aero short box dry vans

– Partial-aero short box refrigerated vans

– Non-aero box vans (all lengths of dry and refrigerated vans)

– Non-box highway (tanker, platform, container chassis, and all other types of highway

trailers that are not box trailers).

The partial-aero box trailers would have similar stringencies as their corresponding full-aero 

trailers in the early phase-in years, but would have separate, reduced standards as the program 

becomes fully implemented. 

The analysis in the following sections describes our evaluation of two alternative 

stringencies with similar technologies. In the first analysis we projected adoption rates that were

used to develop the proposed standards in MY 2027. The second analysis considers the same 

technologies with less lead time to achieve similar adoption rates.

The agencies did consider an alternative that differentiated tanker trailers, platform 

trailers, and container chassis from the other non-box highway trailers to include aerodynamic 

technologies on a fraction of these trailer types. However, an evaluation of this alternative is not 

included here. As discussed in Section IV of the preamble for this proposal, a majority of the 
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non-box trailer manufacturers meet the definition of small business.

O

EPA convened and the 

agencies are proposing to follow the recommendations of the Small Business Advocacy Review 

panel required by the Small Business Regulatory Enforcement Fairness Act (SBREFA). This 

panel concluded that aerodynamic requirements for non-box trailer manufacturers would 

disproportionately burden small manufacturers and they recommended that no aerodynamic 

requirements be proposed.

2.10.2 Defining the Proposed Trailer Technology Packages

The impact of a trailer on the overall fuel efficiency and CO2 emissions of a tractor-trailer 

vehicle varies depending on three main characteristics of the trailer: aerodynamic drag, rolling 

resistance, and weight. In this section, we outline the technologies that the agencies evaluated 

for the proposed standards. 

2.10.2.1 Aerodynamic Drag Reduction

The rigid, rectangular shape of box trailers creates significant aerodynamic drag and 

makes them ideal candidates for aerodynamic technologies that can reduce drag and improve 

fuel consumption and CO2 emissions. Current aerodynamic technologies for box trailers have 

shown significant drag reductions, as discussed below. These technologies are designed to 

create a smooth transition of airflow from the tractor, around the trailer, and beyond the trailer. 

Box trailers provide opportunities to address drag at the front, rear, and underside of the trailer, 

and the agencies considered several types of aerodynamic devices designed to address drag at all 

of these points. Table 2-69 lists general aerodynamic technologies that the EPA SmartWay

program has evaluated for use on box trailers and a description of their intended impact. Several 

versions of each of these technologies are commercially available and have seen increased 

adoption over the past decade. Performance of these devices varies based on their design, their 

location and orientation on the trailer, and the vehicle speed. 

Table 2-69 Aerodynamic Technologies for Box Trailers

LOCATION 

ON TRAILER

EXAMPLE TECHNOLOGIES INTENDED IMPACT ON AERODYNAMICS

Front Front fairings and gap-reducing 

fairings

Reduce cross-flow through gap and smoothly 

transition airflow from tractor to the trailer

Rear Rear fairings, boat tails and flow

diffusers

Reduce pressure drag induced by the trailer wake

Underside Side fairings and skirts, and 

underbody devices

Manage flow of air underneath the trailer to reduce

turbulence, eddies and wake

2.10.2.1.1 Performance of Aerodynamic Technologies

SmartWay-verified technologies are evaluated on 53-foot dry vans. The verified 

technologies are grouped into bins that represent one percent, four percent, or five percent fuel 

 

O The Regulatory Flexibility Act defines small entities as including “small businesses,” “small governments,” and 

“small organizations” (5 USC 601) and references the Small Business Act for the definition of “small businesses” 

using size standards based on the North American Industry Classification System (NAICS) (13 CFR 121.201).
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savings relative to a typical long-haul tractor-trailer at 65-mph cruise conditions. Use of verified 

aerodynamic devices totaling at least five percent fuel savings, along with verified tires, qualifies 

a 53-foot dry van trailer for the “SmartWay Trailer” designation. In 2014, EPA expanded the 

program to include refrigerated vans and provided a “SmartWay Elite” designation if fleets adopt 

verified tires and aerodynamic equipment providing nine percent or greater fuel savings. Todate, nine aerodynamic technology packages from five manufacturers have received the 

SmartWay Elite designation. We may refer to SmartWay verification levels in this analysis, 

since the trailer industry is most familiar with these values as a measure of trailer performance. 

It is important to note that the cruise speed results presented in SmartWay do not 

necessarily represent performance that would be observed in real world operation. Additionally, 

EPA’s Greenhouse gas Emissions Model (GEM), which is the tool the agencies are proposing to 

use for trailer compliance, uses a weighted average of three drive cycles in its vehicle simulation. 

The CO2 and fuel consumption reductions calculated in GEM may differ from those measured in 

SmartWay’s performance tests. Figure 2-17 shows a comparison of the CO2 reductions observed 

for the three individual drive cycles simulated in GEM and the reductions using a combination of 

the three GEM cycles with the cycle weightings assigned to long-haul tractor-trailers in this 

proposed rulemaking (i.e., 86 percent 65-mph cruise, 9 percent 55-mph cruise, and 5 percent 

transient). These results could be used to estimate the difference in performance when 

comparing a constant, 65-mph cruise test similar to SmartWay’s performance tests or the results 

from GEM simulations used for compliance to other driving conditions. These results suggest 

that the SmartWay Elite target improvement of nine percent would be closer to eight percent 

using GEM’s long-haul simulation. It can also be seen that very little benefit is seen for tractortrailers driving under highly transient conditions. These results are for illustrative purposes only 

and do not provide an exact correlation between test results, real-world results, and results from 

GEM. 

0%

2%

4%

6%

8%

10%

12%

14%

16%

4.0 4.5 5.0 5.5 6.0 6.5

C

O2 Reductions (%)

Aerodynamic Drag Area, CdA (m2)

CO2 Reductions for Simulated Long-Haul Dry Van 

(Compare GEM Cycles)

65-MPH Cruise Long-Haul Weighted 55-MPH Cruise Transient 

SmartWay

Verified

SmartWay

Elite

Figure 2-17 Comparison of Weighted and 65-mph Cruise Results using EPA's GEM for a Long Dry Van
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In this analysis, the aerodynamic performance of a tractor-trailer vehicle is quantified by

the aerodynamic drag area, CdA (coefficient of drag multiplied by frontal area), which is a 

function of both tractor and trailer aerodynamic characteristics. EPA’s aerodynamic testing of 

Class 8 high roof sleeper cab tractors pulling standard 53-foot dry vans with zero aerodynamic 

technologies produced an average CdA value of 6.2 m2in coastdown testing and an average

zero-yaw CdA value of 5.5 m2in wind tunnel testing (see Chapter 3.2.4.1). EPA also performed 

wind tunnel tests on a Class 7 high roof day cab pulling several configurations of a solo 28-foot 

dry van trailer and two tandem 28-foot dry van trailers. The average zero-yaw CdA value for the 

solo 28-foot trailer configuration with zero aerodynamic technologies was 5.4 m2(a two percent 

difference compared the corresponding test of the 53-foot trailer). 

For this analysis, EPA grouped these common aerodynamic devices into packages of 

individual or combined technologies. Front fairings and gap reducers provide the smallest 

benefit of the aerodynamic technologies considered. Skirts and boat tails come in ranges of sizes 

and vary in effectiveness. For the purpose of this analysis, the agencies grouped these two 

technologies into “basic” and “advanced”. Basic boat tails and skirts achieve SmartWay’s 

verification threshold of four percent at cruise speeds. Advanced tails and skirts achieve 

SmartWay’s five percent verification. These technologies can be used individually, or in 

combination. The overall performance of a combination of devices could be nearly additive in 

terms of the effectiveness of its individual devices. Some devices may work synergistically to 

achieve greater reductions or counteract and provide less reduction. The trailer aerodynamics 

industry continues to evolve and the agencies anticipate further optimization of these devices in 

the future. In addition to these bolt-on technologies, some manufacturers are experimenting with 

physical changes to the trailer design such that the overall construction of the trailer is more 

aerodynamic. 

EPA collected aerodynamic test data for many of the technologies mentioned previously 

on several tractor-trailer configurations, including 53-foot dry vans and 28-foot dry van pup 

trailers. As described in Chapter 3, EPA’s aerodynamic testing included four tractor models, 

three trailer models, and several aerodynamic technologies. The wind tunnel results shown in 

Figure 2-18 indicate there is very little difference in performance between trailer manufacturers 

for their basic trailer models.
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5.6

5.5

5.5

5.3

5.2

5.2

5.1

5.0

5.1

5.0

4.9

5.0

4.6

4.5

4.4

0.0

1.0

2.0

3.0

4.0

5.0

6.0

Trailer 1 Trailer 2 Trailer 3

CdA (m2)

Wind Tunnel Tests: Average CdA

(Average of Four Tractors)

Baseline Tail Skirt 1 Skirt 2 Skirt 2 + Tail

Figure 2-18 Variation in Performance of Trailer Devices due to Trailer Manufacturer

However, the results showed some variation in aerodynamic performance depending on 

the tractor type, device manufacturer, and test method. Figure 2-19 illustrates these variations 

for a single trailer. While there is some variability in the numerical CdA values of the baseline 

(zero technology) tractor-trailers tested, there is less variation in the effect of adding devices. 

For example, the wind tunnel CdA result for adding a skirt and tail to Tractor 1 (orange bar in the 

first column of Figure 2-19) is 4.5 m2and the coastdown CdA result for adding the same skirt 

and tail to Tractor 3 (orange bar in the last column of Figure 2-19) is 5.8 m2. However, when we 

compare the effect of adding the devices by taking into account the change from the baseline 

result, we get a change in CdA (delta CdA) of 0.9 m2for Tractor 1 and 0.8 m2for Tractor 3. 

This reduced variation is one of the motivating factors in our decision to use a delta CdA 

approach for trailers in lieu of requiring an absolute CdA test.P 

 

P Additional considerations include the fact that an absolute test would require a specific standard tractor for testing 

to ensure an apples-to-apples comparison of all trailer test results and a delta CdA approach makes it possible to 

allow device manufacturers to perform tests on their devices and have them pre-approved for any trailer 

manufacturer to apply on their trailers. 
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5.4

5.6

5.6

5.6

6.1

5.9

6.6

5.5

5.7

5.6

5.1

5.2

5.4

5.3

5.0

5.2

5.1

4.9

5.0

5.1

5.0

5.6

5.5

4.5

4.6

4.6

4.5

5.0

5.8

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

Wind Tunnel, 

Tractor 1

Wind Tunnel, 

Tractor 2

Wind Tunnel, 

Tractor 3

Wind Tunnel, 

Tractor 4

Coastdown, 

Tractor 1'

Coastdown, 

Tractor 2

Coastdown, 

Tractor 3'

CdA (m2)

Effect on Absolute CdA

(Multiple Tractors, Multiple Test Methods, Single Trailer)

Baseline Gap Tail Skirt 1 Skirt 2 Skirt 2+Tail

Figure 2-19 Variation in Aerodynamic Performance of Trailer Devices due to Tractor Manufacturer and 

Test Method

2.10.2.1.2 Performance Bins for Aerodynamic Technologies

The agencies developed bins based on changes in CdA (or “delta CdA”) to encompass 

technologies that are expected to provide similar improvements in drag (e.g., most skirts would 

fall into the same bin) and cover the variability due to tractor model, test method, device 

manufacturer, and trailer manufacturer. Figure 2-20 summarizes the trailer aerodynamic test 

results that were used to establish the trailer certification bins. These results show the average 

delta CdA over four tractor types, and two test methods (i.e., wind tunnel and coastdown) using a 

single trailer. 
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Figure 2-20 Aerodynamic Trailer Testing Results used to Establish Bins for Trailer Certification

As seen in Figure 2-21, results from EPA’s testing of solo 28-foot trailers show that a 

basic skirt would fall into Bin II and the addition of a gap reducer improves the aerodynamic 

performance to Bin III or Bin IV levels of drag reduction. It should be noted that while the 

agencies have chosen to test and regulate 28-foot box trailers individually, they are often pulled 

in a tandem configuration, which restricts the type of aerodynamic devices that can be applied on 

the rear of the trailers. We expect rear devices such as boat tails would not be practical for 28-

foot box trailers, since those devices are only deployable when the trailer is in the rear position. 

However, we recognize that other trailer lengths within the short box trailer subcategory (e.g., 

40-foot and 48-foot) would be able to use rear aerodynamic devices and achieve the 

improvements observed in the higher bins.
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Figure 2-21 Aerodynamic Trailer Testing Results for a Solo 28-Foot Dry Van Relative to Proposed Bins

Table 2-70 below illustrates the bin structure that the agencies are proposing as the basis 

for compliance. The table summarizes example technology packages that might be included in 

each bin for two example trailers. 

Table 2-70 Aerodynamic Technology Bins used to Evaluate Trailer Benefits and Costs

BIN DELTA CDA AVERAGE 

DELTA CDA

EXAMPLE TECHNOLOGIES

53-FOOT DRY VAN 28-FOOT DRY VAN

Bin I < 0.09 0.0 No Aero Devices No Aero Devices

Bin II 0.10 - 0.19 0.1 Gap Reducer Skirt

Bin 

III

0.20 - 0.39 0.3 Basic Skirt or Basic Tail Skirt + Gap Reducer 

Bin 

IV

0.40 - 0.59 0.5 Advanced Skirt or Tail Adv. Skirt + Gap Reducer

Bin V 0.60 - 0.79 0.7 Basic Combinations

Bin 

VI

0.80 - 1.19 1.0 Advanced Combinations 

(including SmartWay Elite)

Bin 

VII

1.20 - 1.59 1.4 Optimized Combinations

Bin 

VIII

> 1.60 1.8 Changes to Trailer Construction

Within GEM, the aerodynamic performance of each trailer subcategory is evaluated by

comparing the delta CdA from Table 2-70 to a CdA value representative of a tractor-trailer 

vehicle with zero aerodynamic trailer technologies (i.e., Bin I). The agencies chose to model the 

zero-technology long box dry van using a CdA value of 6.2 m2(the average CdA from EPA’s 

coastdown testing). For long box refrigerated vans, a two percent reduction in CdA was 

assumed to account for the aerodynamic benefit of the TRU at the front of those trailers. A short 

box dry van also received a two percent lower CdA value compared to its 53-foot counterpart, 
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consistent with the reduction observed in EPA’s wind tunnel testing. The CdA value assigned to 

a refrigerated short box van was an additional two percent lower than the short box dry van. 

Special purpose trailers of all lengths are modeled as a short dry van trailer in GEM and have the 

same Bin I CdA value of 6.1 m2. Since there are no aerodynamic requirements for special 

purpose trailers, the rest of the bins are unnecessary. Non-box highway trailers, which are 

modeled as flatbed trailers, were assigned a drag area of 5.0 m2, as was done in the Phase 1 

tractor program for low roof day cabs. Table 2-71 illustrates the absolute drag areas (CdA) 

associated with each aerodynamic bin for each trailer subcategory. 

Table 2-71 Baseline CdA Values Associated with Aerodynamic Bin I (Zero Trailer Technologies) within 

GEM

TRAILER 

SUBCATEGORY

DRY VAN

Long Dry Van 6.2

Short Dry Van 6.1

Long Ref. Van 6.1

Short Ref. Van 6.0

Special Purpose Box 6.1

Non-Box Highway 4.9

2.10.2.1.3 Effect of Wind-Averaged Drag

The agencies recognize that the benefits of aerodynamic devices for trailers can be better 

seen when measured considering multiple yaw angles. To evaluate the effect of wind, we 

compared the zero yaw and wind-averaged results from EPA’s wind tunnel tests. The windaverage results were calculated at 55 mph vehicle speeds, consistent with the procedures in 40 

CFR 1037.810. The results for three trailers, each an average of tests performed on four tractors, 

are shown in Figure 2-22. The wind-averaged analysis consistently results in a larger 

improvement (i.e., delta CdA). The gap reducer technology shows minimal benefit under a zero 

yaw analysis, but a measurable benefit when yaw angles are considered. 

The performance bins and the resulting proposed standards were developed using zero 

yaw drag results. The agencies are not proposing to accept wind averaged drag results, in order 

to maintain consistency between test methods, as was shown in Figure 2-19. The use of windaveraged drag data would result in larger benefits for trailers tested using a wind tunnel or CFD 

compared to same trailers tested using coastdown procedures. The tractor program, which is 

proposing to use wind-averaged drag results, has a reference test method and a correction factor 

to maintain consistency between methods. The trailer program is not proposing to require a 

reference test, in order to reduce the test burden for manufacturers and allow them to choose an 

appropriate test method for their needs and resources. 
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Figure 2-22 Comparison of Zero Yaw and Wind-Averaged Drag Results

2.10.2.2 Tire Rolling Resistance

2.10.2.2.1 Lower Rolling Resistance Tires

On a typical Class 8 long-haul tractor-trailer, over 40 percent of the total energy loss from 

tires is attributed to rolling resistance from the trailer tires.147 Trailer tire rolling resistance 

values collected by the agencies for Phase 1 indicate that the average coefficient of rolling 

resistance (CRR) for new trailer tires was 6.0 kg/ton. This value was applied for the standard 

trailer used for tractor compliance in the Phase 1 tractor program. For Phase 2, the agencies

consider all trailer tires with CRR values below 6.0 kg/ton to be “lower rolling resistance” (LRR) 

tires. For reference, a trailer tire that qualifies as a SmartWay-verified tire must meet a CRR 

value of 5.1 kg/ton, a 15 percent CRR reduction from the trailer tire identified in Phase 1. Our 

research of rolling resistance indicates an additional CRR reduction of 15 percent or more from 

the SmartWay verification threshold is possible with tires that are available in the commercial 

market today.

For this proposal, the agencies are proposing to use the same rolling resistance baseline 

value of 6.0 kg/ton for all trailer subcategories. In the preamble at Section IV, the agencies

request comments including information on current adoption rates of and CRR values for models 

of LRR tires in use by the various trailer types today.

Similar to the case of tractor tires, LRR tires are available as either dual or as single widebased tires for trailers. Single wide-based tires achieve CRR values that are similar to their dual 
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counterparts, but have an added benefit of weight reduction, which can be an attractive option for 

trailers that frequently maximize cargo weight.

2.10.2.2.2 Performance Levels for LRR Tires

Similar to the proposed Phase 2 tractor and vocational vehicle programs, the agencies are 

proposing a tire program based on adoption of lower rolling resistance tires. Feedback from 

several box trailer manufacturers indicates that the standard tires offered on their new trailers are 

SmartWay-verified tires (i.e., CRR of 5.1 kg/ton or better). An informal survey of members 

from the Truck Trailer Manufacturers Association (TTMA) indicates about 35 percent of box 

trailers sold today have SmartWay tires.148 While some trailers continue to be sold with tires of 

higher rolling resistances, the agencies believe most box trailer tires currently achieve the Phase 

1 trailer tire CRR of 6.0 kg/ton or better.

The agencies evaluated two levels of tire performance for this proposal beyond the 

baseline trailer tire with a CRR of 6.0 kg/ton. The first performance level was set at the criteria 

for SmartWay-verification for trailer tires, 5.1 kg/ton, which is a 15 percent reduction in CRR 

from the baseline. As mentioned previously, several tire models available today achieve rolling 

resistance values well below the present SmartWay threshold. Given the multiple year phase-in 

of the standards, the agencies expect that tire manufacturers will continue to respond to demand 

for more efficient tires and will offer increasing numbers of tire models with rolling resistance 

values significantly better than today’s typical LRR tires. In this context, we believe it is 

reasonable to expect a large fraction of the trailer industry could adopt tires with rolling 

resistances at a second performance level that would achieve an additional eight percent 

reduction in rolling resistance (a 22 percent reduction from the Level 1 tire), especially in the 

later stages of the program. The agencies project the CRR for this second level of performance 

to be a value of 4.7 kg/ton. The agencies evaluated these three tire rolling resistance levels,

summarized in Table 2-72, in the feasibility analysis of the following sections. GEM simulations

that apply Level 1 and 2 tires result in CO2 and fuel consumption reductions of two and three 

percent from the Level 1 tire, respectively. 

Table 2-72 Summary of Trailer Tire Rolling Resistance Levels Evaluated

ROLLING

RESISTANCE LEVEL

CRR (KG/TON)

Baseline 6.0

Level 1 5.1

Level 2 4.7

2.10.2.3 Tire Pressure Systems

The inflation pressure of tires also impacts the rolling resistance. Tractor-trailers 

operating with all tires under-inflated by 10 psi have been shown to increase fuel consumed by 

up to one percent.149 Tires can gradually lose pressure from small punctures, leaky valves or 

simply diffusion through the tire casing. Changes in ambient temperature can also affect tire 

pressure. Trailers that remain unused for long periods of time between hauls may experience any 

of these conditions. A 2003 FMCSA report found that nearly one in five trailers had at least one

tire under-inflated by 20 psi or more. If drivers or fleets are not diligent about checking and 
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attending to under-inflated tires, the trailer may have much higher rolling resistance and much 

higher CO2 emissions and fuel consumption.

2.10.2.3.1 Types of Tire Pressure Monitoring Systems

Tire pressure monitoring (TPM) and automatic tire inflation (ATI) systems are designed 

to address under-inflated tires. Both systems alert drivers if a tire’s pressure drops below its set 

point. TPM systems simply monitor the tires and require user-interaction to reinflate to the 

appropriate pressure. Today’s ATI systems take advantage of trailers’ air brake systems to 

supply air back into the tires (continuously or on demand) until a selected pressure is achieved. 

In the event of a slow leak, ATI systems have the added benefit of maintaining enough pressure 

to allow the driver to get to a safe stopping area.150 The agencies believe TPM systems cannot 

sufficiently guarantee the proper inflation of tires due to the inherent user-interaction required. 

Therefore, ATI systems are the only pressure systems the agencies are proposing to recognize in 

Phase 2. 

2.10.2.3.2 Performance of ATI Systems

Estimates of the benefits of ATI systems vary depending on the base level of 

maintenance already performed by the driver or fleet, as well as the number of miles the trailer 

travels. Trailers that are well maintained or that travel fewer miles would experience less 

benefits from ATI systems compared to trailers that often drive with poorly inflated tires or log 

many miles. The agencies believe ATI systems can provide a CO2 and fuel consumption benefit 

to most trailers. With ATI use, trailers that have lower annual vehicle miles traveled (VMT) due 

to long periods between uses would be less susceptible to low tire pressures when they resume 

activity. Trailers with high annual VMT or frequent changes in ambient conditions would 

experience the fuel savings associated with consistent tire pressures. Automatic tire inflation 

systems could provide a CO2 and fuel consumption savings of 0.5-2.0 percent, depending on the 

degree of under-inflation in the trailer system.

Maintaining tire pressure is important to fuel consumption. Tire manufacturers estimate 

a tire pressure 10 psi below target results in a 0.9 percent increase in fuel consumption. Two 

studies have evaluated truck and trailer tire inflation including FMCSA (2003) and TMC 

(2002).152,153 In the 2003 FMCSA study, tire inflation (psi) was measured in 3,200 tractors and 

1,300 trailers. The TMC study measured tire inflation rates in two fleets and found that only 38 

percent of sampled trailer tires were within +/- 5 psi of target pressure as prescribed by tire 

manufacturers. The study also found that more than 20 percent of tires were 20 psi or more 

underinflated and four percent of tires were 50 psi or more underinflated compared to the 

target. The FMCSA study found similar results. These figures suggest under inflation of tractor 

and trailer tires in the U.S. fleet could result in an increase in fuel consumption of approximately

one to two percent. Most recently, FMCSA (2014) evaluated trailer ATI systems in two test 

fleets.154 The study found ATI systems improved fuel consumption 1.4 percent in test trucks as 

compared to control trucks in two fleets. 

NHTSA and EPA recognize the role of proper tire inflation in maintaining optimum tire 

rolling resistance during normal trailer operation. For this proposal, rather than require 

performance testing of ATI systems, the agencies are proposing to recognize the benefits of ATI 
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systems with a single default reduction for manufacturers that incorporate ATI systems into their 

trailer designs. Based on information available today, we believe that there is a narrow range of 

performance among technologies available and among systems in typical use. We propose to 

assign a 1.5 percent reduction in CO2 and fuel consumption for all trailers that implement ATI 

systems, based on information available today.

155 We believe the use of these systems can 

consistently ensure that tire pressure and tire rolling resistance are maintained. We selected the 

levels of the proposed trailer standards with the expectation that a high rate of adoption of ATI 

systems would occur across all on-highway trailers and during all years of the phase-in of the 

program. For a target tire pressure of 100 psi, a 1.5 percent reduction could be achieved 

assuming 30 percent of trailer tires are at their target pressure, 30 percent are 10 psi below target, 

20 percent are 20 psi low, 10 percent are 30 psi low, 5 percent are 40 psi low and 5 percent are 

50 psi or more below target pressure. 

2.10.2.4 Weight Reduction

Reduction in trailer tare (or empty) weight can lead to fuel consumption reductions in two 

ways. For applications where payload is not limited by weight restrictions, the overall weight of 

the tractor and trailer would be reduced and would lead to improved fuel efficiency. For 

applications where payload is limited by weight restrictions, the lower trailer weight would allow 

additional payload to be transported during the truck’s trip, so g/ton-mile emissions would 

decrease. Weight reduction opportunities in trailers exist in both the structural components and 

in the wheels and tires. Manufacturers commonly replace components such as roof posts, bows, 

side posts, cross members, floor joists, and floor sections with lighter weight options. 

Major lower-weight options are not offered consistently by all trailer manufacturers 

across the industry. For example, some manufacturers have already marketed lower-weight 

major components for many years, while others to date have not done so. There is no clear 

“baseline” for current trailer weight against which lower-weight designs could be compared for

regulatory purposes. For this reason, the agencies do not believe it would be appropriate or fair 

across the industry to apply overall weight reductions toward compliance. However, the 

agencies do believe it would be appropriate to allow a manufacturer to account for weight 

reductions that involve substituting very specific, traditionally heavier components with lowerweight options that are not currently widely adopted in the industry. 

The agencies recognize that when weight reduction is applied to a trailer, some operators 

will replace that saved weight with additional payload. To account for this in EPA’s GEM 

vehicle simulation tool, it is assumed that one-third of the weight reduction is applied to the 

payload. For tractor-trailers simulated in GEM, it takes a weight reduction of nearly 1,000 

pounds before a one percent fuel savings is achieved and about a 2,500 pound reduction to reach 

three percent savings. The component substitutions identified by the agencies result in weight 

reductions of less than 500 pounds, yet can cost over $1,000. The agencies believe that few 

trailer manufacturers would apply weight reduction solely as a means of achieving reduced fuel 

consumption and CO2 emissions, and we are proposing standards that can be met without 

reducing weight. However, we are proposing to offer weight reduction as an option for box 

trailer manufacturers who wish to apply it to some of their trailers as part of their emissions 

averaging strategy. 
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2.10.2.4.1 Weight Reduction Options Recognized in this Proposal

The agencies are proposing compliance provisions that would limit the weight-reduction 

options to the substitution of specified components that can be clearly isolated from the trailer as 

a whole. For this proposal, the agencies have identified several conventional components with 

available lighter-weight substitutes (e.g., substituting conventional dual tires with steel wheels 

with single wide-based tires and aluminum wheels). We are proposing values for the associated 

weight-related savings that would be applied with these substitutions for compliance. We 

believe that the initial cost of these component substitutions is currently substantial enough that 

only a relatively small segment of the industry has adopted these technologies today. 

In addition to weight reduction associated with replacing standard steel wheels with 

aluminum versions, and adopting single wide-based tires in place of dual tires, the agencies have 

identified 11 common trailer components that have lighter weight options available.156,157,158,159 

Some of the references include confidential data that outlined weight savings and costs 

associated with these material substitutions. Table 2-73 lists the components, and estimates of 

weight savings and costs obtained by the agencies. Manufacturers that adopt these technologies 

would sum the associated weight reductions and apply those values in GEM. Steel wheels can 

be replaced with aluminum wheels and two dual tires can be replaced with single wide-based 

tires on aluminum wheels. Relatively large weight savings are possible by replacing steel upper 

coupler assemblies or suspension sub-frames with aluminum versions, but these substitutions are 

more expensive and more labor-intensive to install. 

Table 2-73 Weight Reduction Options for Trailers

COMPONENT MATERIAL 

SUBSTITUTION

WEIGHT 

REDUCTION (LB)

Hub and Drum (per axle) Cast Iron to Aluminum 80

Floor Hardwood to Aluminum 375

Floor Hardwood to Composite 245

Floor Crossmembers Steel to Aluminum 203

Landing Gear Steel to Aluminum 50

Rear Door Steel to Aluminum 187

Rear Door Surround Steel to Aluminum 150

Roof Bows Steel to Aluminum 100

Side Posts Steel to Aluminum 300

Slider Box Steel to Aluminum 150

Structure for Suspension Assembly Steel to Aluminum 280

Upper Coupler Assembly Steel to Aluminum 430

2.10.2.5 Effectiveness of Technologies

The agencies are proposing to recognize trailer improvements via four performance 

parameters: aerodynamic drag reduction, tire rolling resistance reduction, and the adoption of 

ATI and weight reduction. Table 2-74 summarizes the performance levels for each of these 

parameters based on the technology characteristics outlined in Section 2.10.2. 
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Table 2-74 Performance Parameters for the Proposed Trailer Program

AERODYNAMICS (DELTA CDA, M2)

Bin I 0.0

Bin II 0.1

Bin III 0.3

Bin IV 0.5

Bin V 0.7

Bin VI 1.0

Bin VII 1.4

Bin VIII 1.8

Tire Rolling Resistance (CRR, kg/ton)

Tire Baseline 6.0

Tire Level 1 5.1

Tire Level 2 4.7

Tire Inflation System (% reduction)

ATI System 1.5

Weight Reduction (pounds)

Weight 1/3 added to payload, remaining 

reduces overall vehicle weight

These performance parameters have different effects on each trailer subcategory due to 

differences in the simulated trailer characteristics. Table 2-75 shows the agencies’ estimates of 

the effectiveness of each parameter for four box trailer types. Each technology was evaluated in 

GEM using the baseline parameter values for the other technology categories. For example, each 

aerodynamic bin was evaluated using the Tire Level 1 (6.0 kg/ton) and the Base weight reduction 

option (zero pounds). The table shows that aerodynamic improvements offer the largest 

potential for CO2 emissions and fuel consumption reductions, making them relatively effective 

technologies. 
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Table 2-75 Effectiveness (Percent Change in CO2 Emissions and Fuel Consumption) of Technologies for the 

Proposed Trailer Program

AERODYNAMICS DELTA CDA (M2) DRY VAN REFRIGERATED VAN

Long Short Long Short

Bin I 0.0 0% 0% 0% 0%

Bin II 0.1 -1% -1% -1% -1%

Bin III 0.3 -2% -2% -2% -2%

Bin IV 0.5 -3% -4% -3% -3%

Bin V 0.7 -5% -5% -5% -5%

Bin VI 1.0 -7% -7% -7% -7%

Bin VII 1.4 -10% -10% -9% -10%

Bin VIII 1.8 -13% -13% -12% -12%

Tire Rolling Resistance CRR (kg/ton) Dry Van Refrigerated Van

Long Short Long Short

Baseline 6.0 0% 0% 0% 0%

Level 1 5.1 -2% -1% -2% -1%

Level 2 4.7 -3% -2% -3% -2%

Weight Reduction Weight (lb) Dry Van Refrigerated Van

Long Short Long Short

Baseline 0.0 0.0% 0.0% 0.0% 0.0%

Option 1 168 -0.2% -0.3% -0.2% -0.3%

Option 2 280 -0.3% -1% -0.3% -1%

Option 3 430 -0.5% -1% -0.5% -1%

Option 4 556 -1% -1% -1% -1%

2.10.3 Defining the Baseline Trailers

2.10.3.1 Baseline Tractor-Trailer Vehicles within GEM

The regulatory purpose of EPA’s heavy-duty vehicle compliance tool, GEM, is to 

combine the effects of trailer technologies through simulation so that they can be expressed as 

kg/ton-mile and gal/100 ton-mile and thus avoid the need for direct testing of each trailer model 

being certified. The proposed trailer program has separate standards for each trailer subcategory, 

and a unique tractor-trailer vehicle was chosen to represent each subcategory for compliance. In 

the Phase 2 update to GEM, each trailer subcategory is modeled as a particular trailer being 

pulled by a standard tractor depending on the physical characteristics and use pattern of the 

trailer. Table 2-76 highlights the relevant vehicle characteristics for the zero-technology baseline 

of each subcategory. Level 1 trailer tires are used, and the drag area, which is a function of the 

aerodynamic characteristics of both the tractor and trailer, is set to the Bin I values shown 

previously in Table 2-71. Weight reduction and ATI systems are not applied in these baselines. 

Chapter 2.10 of the draft RIA provides a detailed description of the development of these 

baseline tractor-trailers. 
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Table 2-76 Characteristics of the Zero-Technology Baseline Tractor-Trailer Vehicles

DRY VAN REFRIGERATED 

VAN

AEROEXCLUDED

BOX

NON-BOX

HIGHWAY

Trailer Length Long Short Long Short All Lengths All Lengths

Tractor Class Class 8 Class 8 Class 8 Class 8 Class 8 Class 8

Tractor Cab Type Sleeper Day Sleeper Day Day Day

Tractor Roof Height High High High High High Low

Engine 2018 MY 

15L, 

455 HP

2018 MY 

15L, 

455 HP

2018 MY 

15L, 

455 HP

2018 MY 

15L, 

455 HP

2018 MY 

15L, 

455 HP

2018 MY 

15L, 

455 HP

Frontal Area (m2) 10.4 10.4 10.4 10.4 10.4 6.9

Baseline Drag Area, CdA (m2) 6.2 6.1 6.1 6.0 6.1 4.9

Steer Tire RR (kg/ton) 6.54 6.54 6.54 6.54 6.54 6.54

Drive Tire RR (kg/ton) 6.92 6.92 6.92 6.92 6.92 6.92

Trailer Tire RR (kg/ton) 6.00 6.00 6.00 6.00 6.00 6.00

Total Weight (kg) 31978 21028 33778 22828 21028 29710

Payload (tons) 19 10 19 10 10 19

ATI System Use 0 0 0 0 0 0

Weight Reduction (lb) 0 0 0 0 0 0

Drive Cycle Weightings

65-MPH Cruise 86% 64% 86% 64% 64% 64%

55-MPH Cruise 9% 17% 9% 17% 17% 17%

Transient Driving 5% 19% 5% 19% 19% 19%

2.10.3.2 Reference Case Tractor-Trailer Vehicles to Evaluate Benefits and Costs

In order to evaluate the benefits and costs of the proposed standards, it is necessary to 

establish a reference point for comparison. The technologies described in Section 2.10.2 exist in 

the market today, and their adoption is driven by available fuel savings as well as by the 

voluntary SmartWay Partnership and California’s Heavy Duty Greenhouse Gas Emission 

Reduction Measure tractor-trailer requirements. For this proposal, the agencies identified 

reference case tractor-trailers for each trailer subcategory based on the technology adoption rates 

we project would exist if this proposed trailer program was not implemented. 

The agencies believe research funded and conducted by the federal government, industry, 

academia and other organizations is likely to result in the adoption of some technologies beyond 

the levels required to comply with existing regulatory and voluntary programs. One example of 

such research is the Department of Energy Super Truck program160 which has a goal of 

demonstrating cost-effective measures to improve the efficiency of Class 8 long-haul freight

trucks by 50 percent by 2015. For purposes of our reference case, we project that by 2018, 

absent further California regulation, EPA’s SmartWay program and these research programs will 

result in about 20 percent of 53-foot dry and refrigerated vans adopting basic SmartWay-level 

aerodynamic technologies (meeting SmartWay’s four percent verification level and Bin III from 

Table 2-74),

161,162,163 30 percent adopting more advanced aerodynamic technologies at the five 

percent SmartWay-verification level (Bin IV), and five percent adding combinations of 

technologies (Bin V). In addition, we project half of these 53’ box trailers will be equipped with 

SmartWay-verified tires (i.e., 5.1 kg/ton) and ATI systems as well. The agencies project market 

forces will drive an additional one percent increase in adoption of the advanced SmartWay and 
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tire technologies each year through 2027. For analytical purposes, the agencies assumed 

manufacturers of the shorter box trailers and other trailer subcategories would not adopt these 

technologies in the timeframe considered and a zero-technology baseline is assumed. We are not 

assuming any weight reduction for any of the trailer subcategories in the reference cases. Table 

2-77 summarizes the reference case trailers for each trailer subcategory. 

Table 2-77 Adoption Rates and Average Performance Parameters for the Reference Case Trailers

TECHNOLOGY LONG BOX

DRY & REFRIGERATED 

VANS

SHORT BOX, 

NON-AERO BOX, 

& NON-BOX TRAILERS

Model Year 2018 2021 2024 2027 2018 - 2027

Aerodynamics

Bin I 45% 41% 38% 35% 100%

Bin II - - - - -

Bin III 20% 20% 20% 20% -

Bin IV 30% 34% 37% 40% -

Bin V 5% 5% 5% 5% -

Bin VI - - - - -

Bin VII - - - -

Bin VIII - - - - -

Average Delta CdA (m2)

a

0.2 0.3 0.3 0.3 0.0

Tire Rolling Resistance

Baseline tires 50% 47% 43% 40% 100%

Level 1 tires 50% 53% 57% 60% -

Level 2 tires - - - - -

Average CRR (kg/ton) a5.55 5.52 5.49 5.46 6.0

Tire Inflation

ATI 50% 53% 57% 60% 0%

Average % Reduction a0.8% 0.8% 0.9% 0.9% 0.0%

Weight Reduction (pounds)

Weight b0 0 0 0 0

Notes: 

a Combines adoption rates with performance levels shown in Table 2-74

b Weight reduction was not projected for the reference case trailers

Also shown in Table 2-77 are average aerodynamic performance (delta CdA), average 

tire rolling resistance (CRR), and average reductions due to use of ATI and weight reduction for 

each stage of the proposed program. These values indicate the performance of theoretical 

average tractor-trailers that the agencies project would be in use if no federal regulations were in 

place for trailer CO2 and fuel consumption. The average tractor-trailer vehicles serve as 

reference cases for each trailer subcategory. 

In addition to the reference case described above, a second reference case was developed 

by the agencies. This alternative reflects the possibility that absent a Phase 2 regulation, there 

will be continuing adoption of technologies in the trailer market after 2027 that reduce fuel 

consumption and CO2 emissions. This alternative assumes that by 2040, 75 percent of new 

trailers will be equipped with SmartWay-verified aerodynamic devices and low rolling resistance 

tires, and ATI. Table 2-78 shows the adoption rates of technologies in the alternative reference 

case.
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Table 2-78 Adoption Rates and Average Performance Parameters for the Alternative Reference Case

TECHNOLOGY LONG BOX

DRY & REFRIGERATED VANS

SHORT BOX, 

NON-AERO BOX, 

& NON-BOX TRAILERS

Model Year 2018 2021 2024 2027 2040 2018 - 2027

Aerodynamics

Bin I 45% 41% 38% 35% 20% 100%

Bin II - - - - - -

Bin III 20% 20% 20% 20% 20% -

Bin IV 30% 34% 37% 40% 55% -

Bin V 5% 5% 5% 5% 5% -

Bin VI - - - - - -

Bin VII - - - - -

Bin VIII - - - - - -

Average Delta CdA (m2)

a

0.2 0.3 0.3 0.3 0.4 0.0

Tire Rolling Resistance

Baseline tires 50% 47% 43% 40% 25% 100%

Level 1 tires 50% 53% 57% 60% 75% -

Level 2 tires - - - - - -

Average CRR (kg/ton) a5.6 5.5 5.5 5.5 5.3 6.0

Tire Inflation

ATI 50% 53% 57% 60% 75% 0%

Average % Reduction a0.8% 0.8% 0.9% 0.9% 1.1% 0.0%

Weight Reduction (pounds)

Weight b0 0 0 0 0 0

The agencies applied the vehicle attributes from Table 2-77 and the average performance 

values from Table 2-74 in the proposed Phase 2 GEM vehicle simulation to calculate the CO2 

emissions and fuel consumption performance of the reference tractor-trailers. The results of 

these simulations are shown in Table 2-79. We used these CO2 and fuel consumption values to 

calculate the relative benefits of the proposed standards. Note that the large difference between 

the per ton-mile values for long and short trailers is due primarily to the large difference in 

assumed payload (19 tons compared to 10 tons) as seen in and discussed further in the Chapter 

2.10.3. The alternative baseline in Table 2-78 impacts the long-term projections of benefits

beyond 2027, which are analyzed in Chapters 5 through 7 of this draft RIA. The non-box trailers 

and non-aero box vans are not included in this reference case analysis, because we are proposing 

design standards for these trailers. As such, these trailers would not have standards to meet. 

Instead, they would have minimum tire requirements. 

Table 2-79 CO2 Emissions and Fuel Consumption Results for the Reference Case Tractor-Trailers

DRY VAN REFRIGERATED 

VAN

Length Long Short Long Short

CO2 Emissions 

(kg/ton-mile) 85 147 87 151

Fuel Consumption 

(gal/100 ton-miles) 8.3497 14.4401 8.5462 14.8330
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2.10.4 Effectiveness and Costs of the Proposed Standards 

The agencies evaluated several alternatives for the proposed trailer program. The 

analysis below is for the alternative we believe reflects the agencies’ statutory authorities. This 

alternative is fully implemented in model year (MY) 2027. The agencies believe that a period of 

more than 10 years provides the industry sufficient lead time to meet the stringency requirements 

proposed.

2.10.4.1 Projected Technology Adoption Rates for the Proposed Standards

Table 2-80 and Table 2-81 provide a set of adoption rates that a manufacturer could apply 

to meet the standards of this proposed rulemaking. These adoption rates begin with 60 percent 

of long box trailers achieving current SmartWay level aerodynamics (Bin IV) and progress to 90 

percent achieving SmartWay Elite or better over the following nine years. Short box trailers 

adopt single aero devices in 2021 MY and combinations of devices by 2027 MY. Both long and 

short refrigerated vans have less stringent aerodynamic requirements in the later years to reflect 

the reduced number of aerodynamic options they have due to their TRUs. Similarly, we are 

proposing that partial-aero trailers of the various sizes would continue to be subject to the 

corresponding 2024 MY standards in 2027 and later model years to account for the workperforming devices that may inhibit the use of some technology combinations. The adoption 

rates for the long box trailers include some technologies that meet SmartWay Elite verification 

levels. The short box trailers would also include some combinations of devices. The agencies 

expect these adoption rates could be feasible in the next decade. The agencies believe trailer 

manufacturers and manufacturers of bolt-on aerodynamic devices will have incentive to design 

single-components or trailer features that accommodate work-performing devices and achieve 

these levels of performance by MY 2027.

The agencies project that nearly all box trailers would adopt tire technologies to comply

with the standards and the agencies projected consistent adoption rates across all lengths of dry

and refrigerated vans. As mentioned previously, the agencies did not include weight reduction in 

their technology adoption projections, but manufacturers can use weight reduction as part of their 

compliance strategy. 

The adoption rates shown in these tables are one set of many possible combinations that 

box trailer manufacturers could apply to achieve the same average stringency. If a manufacturer 

chose these adoption rates, a variety of technology options exist within the aerodynamic bins, 

and several models of LRR tires exist for the levels shown. Alternatively, technologies from

both higher and lower aero bins and tire levels could be used to comply. It should be noted that 

manufacturers are not limited to aerodynamic and tire technologies. Certain types of weight 

reduction, for example, may be used as a compliance pathway. Similar to the reference cases, 

the agencies derived a single set of performance parameters for each subcategory by weighting 

the performance levels included in Table 2-74 by the corresponding adoption rates. These 

performance parameters represent an average compliant vehicle for each trailer subcategory. 
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Table 2-80 Adoption Rates and Average Performance Parameters for the Long Box Trailers

TECHNOLOGY LONG BOX

DRY VANS

LONG BOX

REFRIGERATED VANS

Model Year 2018 2021 2024 2027 2018 2021 2024 2027

Aerodynamic Technologies

Bin I 5% - - - 5% - - -

Bin II - - - - - - - -

Bin III 30% 5% - - 30% 5% - -

Bin IV 60% 55% 25% - 60% 55% 25% -

Bin V 5% 10% 10% 10% 5% 10% 10% 20%

Bin VI - 30% 65% 50% - 30% 65% 60%

Bin VII - - - 40% - - - 20%

Bin VIII - - - - - - - -

Average Delta CdA (m2)

a

0.4 0.7 0.8 1.1 0.4 0.7 0.8 1.0

Trailer Tire Rolling Resistance

Baseline tires 15% 5% 5% 5% 15% 5% 5% 5%

Level 1 tires 85% 95% - - 85% 95% - -

Level 2 tires - - 95% 95% - - 95% 95%

Average CRR (kg/ton) a5.2 5.1 4.8 4.8 5.2 5.1 4.8 4.8

Tire Inflation System

ATI 85% 95% 95% 95% 85% 95% 95% 95%

Average ATI Reduction (%) a1.3% 1.4% 1.4% 1.4% 1.3% 1.4% 1.4% 1.4%

Weight Reduction (pounds)

Weight b0 0 0 0 0 0 0 0

Notes: 

a Combines adoption rates with performance levels shown in Table 2-74

b This set of adoption rates did not apply weight reduction to meet the proposed standards for these trailers
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Table 2-81 Adoption Rates and Average Performance Parameters for the Short Box Trailers

TECHNOLOGY SHORT BOX

DRY VANS

SHORT BOX

REFRIGERATED VANS

Model Year 2018 2021 2024 2027 2018 2021 2024 2027

Aerodynamic Technologies a

Bin I 100% 5% - - 100% 5% - -

Bin II - 95% 70% 30% - 95% 70% 55%

Bin III - - 30% 60% - - 30% 40%

Bin IV - - - 10% - - - 5%

Bin V - - - - - - - -

Bin VI - - - - - - - -

Bin VII - - - - - - - -

Bin VIII - - - - - - - -

Average Delta CdA (m2)

b

0.4 0.7 0.8 1.1 0.4 0.7 0.8 1.0

Trailer Tire Rolling Resistance

Baseline tires 15% 5% 5% 5% 15% 5% 5% 5%

Level 1 tires 85% 95% - - 85% 95% - -

Level 2 tires - - 95% 95% - - 95% 95%

Average CRR (kg/ton) b5.2 5.1 4.8 4.8 5.2 5.1 4.8 4.8

Tire Inflation System

ATI 85% 95% 95% 95% 85% 95% 95% 95%

Average ATI Reduction (%) c1.3% 1.4% 1.4% 1.4% 1.3% 1.4% 1.4% 1.4%

Weight Reduction (pounds)

Weight b0 0 0 0 0 0 0 0

Notes: 

a The majority of short box trailers are 28 feet in length. We recognize that they are often operated in tandem, which limits the 

technologies that can be applied (for example, boat tails). We established standards assuming these shorter trailers were run solo, 

but projected reduced aerodynamic improvements compared to the longer trailers with similar technologies to reflect their 

frequent tandem operation.

b Combines adoption rates with performance levels shown in Table 2-74

c This set of adoption rates did not apply weight reduction to meet the proposed standards for these trailers

Non-box and non-aero box trailers, with two or more work-related special components, 

are not shown in the tables above. These trailers are projected to adopt tire technologies with 

zero adoption of aerodynamic technologies. As shown in Table 2-82, we are projecting 100 

percent adoption rates of these technologies at each stage of the program, which would

significantly reduce the compliance burden for manufacturers by reducing the amount of tracking 

and eliminating the need to run GEM. The agencies are proposing these tire-only requirements 

in two stages. In 2018 MY, manufacturers would be required to use tires meeting a rolling 

resistance of Level 2 or better and apply ATI systems on all non-box and non-aero box trailers. 

In 2024 MY, ATI and LRR tires at a Level 3 or better would be required. The agencies are 

proposing ATI at all stages of the program. 
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Table 2-82 Adoption Rates and Average Performance Parameters for the Non-Aero Box and Non-Box 

Trailers

TECHNOLOGY NON-AERO BOX

& NON-BOX TRAILERS

Model Year 2018 2021 2024+

Aerodynamic Technologies

Bin I 100% 100% 100%

Bin II - - -

Bin III - - -

Bin IV - - -

Bin V - - -

Bin VI - - -

Bin VII - - -

Bin VIII - - -

Average Delta CdA (m2)

a

0.0 0.0 0.0

Trailer Tire Rolling Resistance

Baseline tires - - -

Level 1 tires 100% 100% -

Level 2 tires - - 100%

Average CRR (kg/ton) a5.1 5.1 4.7

Tire Inflation System

ATI 100% 100% 100%

Average ATI Reduction (%) a1.5% 1.5% 1.5%

Weight Reduction (pounds)

Weight b0 0 0

Notes: 

a Combines adoption rates with performance levels shown in Table 2-74

b This set of adoption rates did not apply weight reduction to meet the proposed standards 

for these trailers

2.10.4.2 Derivation of the Proposed Standards 

The average performance parameters from Table 2-80 and Table 2-81 were applied as 

input values to the GEM vehicle simulation to derive the proposed HD Phase 2 fuel consumption 

and CO2 emissions standards for each subcategory of box trailers. 

The proposed standards are shown in Table 2-83. Over the four phases of the proposed 

rules, box trailers longer than 50 feet would, on average, reduce their CO2 emissions and fuel 

consumption by three percent, five percent and seven percent compared to their reference cases 

for each year in Table 2-79. Box trailers 50-foot and shorter would achieve reductions of two 

percent, four percent and five percent compared to their reference cases. The tire technologies 

used on non-box and special purpose box trailers would provide reductions of three percent in 

the first two stages and achieve four percent by 2027.
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Table 2-83 CO2 Emissions and Fuel Consumption Based on Projected Technology Adoption Rates for 

Proposed Standards

MODEL 

YEAR

SUBCATEGORY DRY VAN REFRIGERATED

VAN

Length Long Short Long Short

2018 -

2020

EPA Standard

(CO2 Grams per Ton-Mile) 83 144 84 147

Voluntary NHTSA Standard

(Gallons per 1,000 TonMile)8.1532 14.1454 8.2515 14.4401

2021 -

2023

EPA Standard

(CO2 Grams per Ton-Mile) 81 142 82 146

NHTSA Standard

(Gallons per 1,000 TonMile)7.9568 13.9489 8.0550 14.3418

2024 -

2026

EPA Standard

(CO2 Grams per Ton-Mile) 79 141 81 144

NHTSA Standard

(Gallons per 1,000 TonMile)7.7603 13.8507 7.9568 14.1454

2027 +

EPA Standard

(CO2 Grams per Ton-Mile) 77 140 80 144

NHTSA Standard

(Gallons per 1,000 TonMile)7.5639 13.7525 7.8585 14.1454

2.10.4.3 Projected Cost of Proposed Trailer Standards

The agencies evaluated technology costs for 53-foot dry and refrigerated vans and 28-

foot dry vans, which we believe are representative of the majority of trailers in the long and short 

box trailer categories, respectively. Similar tire technology costs were assumed for the non-box 

trailer subcategory. We identified costs for each technology package evaluated and projected out 

the costs for each year of the program. A summary of the technology costs is included in Table 

2-84 through Table 2-86 for model years 2018, 2021 and 2024, respectively, with additional 

details available in Chapter 2.12. Costs shown in the following tables are for the specific model 

year indicated and are incremental to the average reference case costs, which includes some level 

of adoption of these technologies as shown in Table 2-77. Therefore, the technology costs in the 

following tables reflect the average cost expected for each of the indicated trailer subcategories. 

Note that these costs do not represent actual costs for the individual components, because some 

fraction of the component costs has been subtracted to reflect some use of these components in 

the reference case. These costs include indirect costs via markups along with learning impacts

and also reflect estimated costs of the compliance process. For more on the estimated 

technology costs exclusive of adoption rates, refer to Chapter 2.12. 

Table 2-84 Trailer Technology Incremental Costs in the 2018 Model Year for the Proposed Alternative 

(2012 $)

53-FOOT

DRY VAN

53-FOOT

REF. VAN

28-FOOT

DRY VAN

NON-BOX 

HIGHWAY

Aerodynamics $285 $285 $0 $0

Tires $65 $65 $78 $185
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Tire inflation system $239 $239 $435 $683

Total $588 $588 $514 $868

Table 2-85 Trailer Technology Incremental Costs in the 2021 Model Year for the Proposed Alternative

(2012 $)

53-FOOT

DRY VAN

53-FOOT

REF. VAN

28-FOOT

DRY VAN

NON-BOX 

HIGHWAY

Aerodynamics $602 $602 $468 $0

Tires $65 $65 $79 $175

Tire inflation system $234 $234 $426 $632

Total $901 $901 $974 $807

Table 2-86 Trailer Technology Incremental Costs in the 2024 Model Year for the Proposed Alternative 

(2012 $)

53-FOOT

DRY VAN

53-FOOT

REF. VAN

28-FOOT

DRY VAN

NON-BOX 

HIGHWAY

Aerodynamics $836 $836 $608 $0

Tires $61 $61 $76 $160

Tire inflation system $220 $220 $412 $578

Total $1,116 $1,116 $1,097 $739

Table 2-87 Trailer Technology Incremental Costs in the 2024 Model Year for the Proposed Alternative 

(2012 $)

53-FOOT

DRY VAN

53-FOOT

REF. VAN

28-FOOT

DRY VAN

NON-BOX 

HIGHWAY

Aerodynamics $1,163 $1,034 $788 $0

Tires $54 $54 $74 $155

Tire inflation system $192 $192 $391 $549

Total $1,409 $1,280 $1,253 $704

2.10.5 Effectiveness and Costs of a More Stringent Trailer Alternative

The agencies also evaluated a more stringent alternative that considered the same 

technologies with less lead time. The reference cases from Section 2.10.3.2 apply for this 

alternative. Additionally, the projected adoption rates for the non-aero box and non-box trailer 

subcategories remain unchanged in this alternative, so their results are not repeated in this 

section.

2.10.5.1 Projected Adoption Rates for More Stringent Alternative

From Table 2-88 and Table 2-89, it can be seen that the 2018 MY aerodynamic 

technology adoption rates and the tire technology adoption rates for all model years are identical 

to those presented previously for the proposed standards. The aerodynamic projections for 2021 

MY and 2024 MY in this more stringent alternative are the same as those projected for 2024 MY 
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and 2027 MY of the proposed standards, but are applied three years earlier. In this alternative, 

the 2021 MY adoption rates would continue to apply for the partial-aero box trailers in 2024 and 

later model years. 

Table 2-88 Adoption Rates and Average Performance Parameters for the Long Box Trailers in the More 

Stringent Alternative

TECHNOLOGY LONG BOX

DRY VANS

LONG BOX

REFRIGERATED VANS

Model Year 2018 2021 2024 2018 2021 2024

Aerodynamic Technologies a

Bin I 5% - - 5% - -

Bin II - - - - - -

Bin III 30% - - 30% - -

Bin IV 60% 25% - 60% 25% -

Bin V 5% 10% 10% 5% 10% 20%

Bin VI - 65% 50% - 65% 60%

Bin VII - - 40% - - 20%

Bin VIII - - - - - -

Average Delta CdA (m2)

a

0.4 0.8 1.1 0.4 0.8 1.0

Trailer Tire Rolling Resistance

Baseline tires 15% 5% 5% 15% 5% 5%

Level 1 tires 85% 95% - 85% 95% -

Level 2 tires - - 95% - - 95%

Average CRR (kg/ton) a5.2 5.1 4.8 5.2 5.1 4.8

Tire Inflation System

ATI 85% 95% 95% 85% 95% 95%

Average ATI Reduction (%) a1.3% 1.4% 1.4% 1.3% 1.4% 1.4%

Weight Reduction (pounds)

Weight b0 0 0 0 0 0

Notes: 

a Combines adoption rates with performance levels shown in Table 2-74

b This set of adoption rates did not apply weight reduction to meet the proposed standards for these trailers
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Table 2-89 Adoption Rates and Average Performance Parameters for the Short Box Trailers in the More 

Stringent Alternative

TECHNOLOGY SHORT BOX

DRY VANS

SHORT BOX

REFRIGERATED VANS

Model Year 2018 2021 2024 2018 2021 2024

Aerodynamic Technologies a

Bin I 100% - - 100% - -

Bin II - 70% 30% - 70% 55%

Bin III - 30% 60% - 30% 40%

Bin IV - - 10% - - 5%

Bin V - - - - - -

Bin VI - - - - - -

Bin VII - - - - - -

Bin VIII - - - - - -

Average Delta CdA (m2)

b

0.4 0.8 1.1 0.4 0.8 1.0

Trailer Tire Rolling Resistance

Baseline tires 15% 5% 5% 15% 5% 5%

Level 1 tires 85% 95% - 85% 95% -

Level 2 tires - - 95% - - 95%

Average CRR (kg/ton) b5.2 5.1 4.8 5.2 5.1 4.8

Tire Inflation System

ATI 85% 95% 95% 85% 95% 95%

Average ATI Reduction (%) b1.3% 1.4% 1.4% 1.3% 1.4% 1.4%

Weight Reduction (pounds)

Weight c0 0 0 0 0 0

Notes: 

a The majority of short box trailers are 28 feet in length. We recognize that they are often operated in tandem, which 

limits the technologies that can be applied (for example, boat tails). We established standards assuming these shorter 

trailers were run solo, but projected reduced aerodynamic improvements compared to the longer trailers with similar 

technologies to reflect their frequent tandem operation.

b Combines adoption rates with performance levels shown in Table 2-74

c This set of adoption rates did not apply weight reduction to meet the proposed standards for these trailers

2.10.5.2 Derivation of the More Stringent Alternative Standards

Similar to the proposed standards of Section 2.10.4.2, the agencies applied the technology

performance values from Table 2-88 and Table 2-89 as GEM inputs to derive the proposed 

standards for each subcategory. 

Table 2-90 shows the resulting standards for the more stringent alternative. Over the 

three phases of the alternative, box trailers longer than 50 feet would, on average, reduce their 

CO2 emissions and fuel consumption by four percent, six percent and eight percent. Box trailers 

50-foot and shorter would achieve reductions of two percent, four percent, and five percent

compared to the reference case. Partial-aero box trailers would continue to be subject to the 

2021 MY standards for MY 2024 and later. The non-aero box and non-box trailers would meet 

the same standards and achieve the same three and four percent benefits as shown in the 

proposed alternative. 
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Table 2-90 Trailer CO2 and Fuel Consumption Standards for Box Trailers in the More Stringent Alternative

MODEL 

YEAR

SUBCATEGORY DRY VAN REFRIGERATED 

VAN

Length Long Short Long Short

2018 - 2020

EPA Standard

(CO2 Grams per Ton-Mile) 83 144 84 147

Voluntary NHTSA Standard

(Gallons per 1,000 Ton-Mile) 8.1532 14.1454 8.2515 14.4401

2021 - 2023

EPA Standard

(CO2 Grams per Ton-Mile) 80 142 81 145

NHTSA Standard

(Gallons per 1,000 Ton-Mile) 7.8585 13.9489 7.9568 14.2436

2024 +

EPA Standard

(CO2 Grams per Ton-Mile) 77 140 80 144

NHTSA Standard

(Gallons per 1,000 Ton-Mile) 7.5639 13.7525 7.8585 14.1454

2.10.5.3 Projected Cost of the More Stringent Trailer Alternative

A summary of the technology costs is included in Table 2-91 to Table 2-93 for MYs 

2018, 2021 and 2024, with additional details available in Chapter 2.12. Costs shown in the 

following tables are for the specific model year indicated and are incremental to the average 

reference case costs, which includes some level of adoption of these technologies as shown in

Table 2-77. Therefore, the technology costs in the following tables reflect the average cost 

expected for each of the indicated trailer classes. Note that these costs do not represent actual 

costs for the individual components because some fraction of the component costs has been 

subtracted to reflect some use of these components in the reference case. For more on the 

estimated technology costs exclusive of adoption rates, refer to Chapter 2.12 of this draft RIA. 

These costs include indirect costs via markups along with learning impacts. It can be seen that, 

despite the similar stringencies for MY 2024 of this more stringent alternative and MY 2027 of 

the proposed alternative, the costs shown below are slightly higher. The lower cost in the 

proposed MY 2027 can be partially attributed to the reduced costs due to three years of 

additional learning. For a description of the markups and learning impacts considered in this 

analysis and how it impacts technology costs for other years, refer to the draft RIA Chapter 2.12.

Table 2-91 Trailer Technology Incremental Costs in the 2018 Model Year for the More Stringent Alternative 

(2012$)

>50-FOOT

DRY VAN

>50-FOOT

REF. VAN

<35-FOOT

DRY VAN

NON-BOX 

HIGHWAY

Aerodynamics $285 $285 $0 $0

Tires $65 $65 $78 $185

Tire inflation system $239 $239 $435 $683

Total $588 $588 $514 $868
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Table 2-92 Trailer Technology Incremental Costs in the 2021 Model Year for the More Stringent Alternative 

(2012$)

>50-FOOT

DRY VAN

>50-FOOT

REF. VAN

<35-FOOT

DRY VAN

NON-BOX

HIGHWAY

Aerodynamics $908 $908 $641 $0

Tires $65 $65 $79 $175

Tire inflation system $234 $234 $426 $632

Total $1,207 $1,207 $1,146 $807

Table 2-93 Trailer Technology Incremental Costs in the 2024 Model Year for the More Stringent Alternative 

(2012$)

>50-FOOT

DRY VAN

>50-FOOT

REF. VAN

<35-FOOT

DRY VAN

NON-BOX

HIGHWAY

Aerodynamics $1,223 $1,090 $816 $0

Tires $61 $61 $76 $160

Tire inflation system $220 $220 $412 $578

Total $1,504 $1,371 $1,304 $739

2.10.6 Evaluation of Compliance Option using GEM-Based Equation

EPA created the Greenhouse gas Emissions Model (GEM) as a compliance tool for 

heavy-duty vehicles. Users provide specific performance parameters to the model and GEM 

calculates CO2 emissions and fuel consumption results. As described previously, the proposed 

Phase 2 GEM is designed to accept four performance variables as trailer inputs: change in drag 

area (delta CDA), tire rolling resistance level (TRRL), automatic tire inflation (ATI) and weight 

reduction (WR). The reduction applied when using an automatic tire inflation system is 

accounted for after the vehicle simulation is complete. The other performance parameters 

directly impact the results of the vehicle simulation, by changing the drag, rolling resistance and 

weight of the simulated vehicle. 

We performed a sensitivity analysis for delta CDA, TRRL and WR to evaluate their effect 

on the model’s results. In the analysis to follow, all of the calculations are shown in terms of 

CO2 emissions; use a conversion of 10,180 grams CO2 per gallon of diesel fuel to calculate the 

corresponding fuel consumption values. Figure 2-23 through Figure 2-26 show GEM’s CO2

results for a parameter sweep of a simulated Class 8 tractor pulling each of the four box van 

trailers. It can be seen that each of the three parameters has a linear impact on CO2 emissions. A 

curve fit was applied to each data set and the equation is displayed on each plot. The intercept in 

each parameter sweep data set is the baseline CO2 result considering a zero-technology trailer,

and this value is consistent for all parameters for a given trailer. The coefficients indicate the 

relationship between the assessed parameter and the model’s CO2 result. 
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(a)

(b)

(c)

Figure 2-23 Impact of (a) Delta CDA, (b) Delta CRR, and (c) Weight Reduction on CO2 Results of a GEMSimulated Long Dry Van
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(a)

(b)

(c)

Figure 2-24 Impact of (a) Delta CDA, (b) Delta CRR, and (c) Weight Reduction on CO2 Results of a GEMSimulated Long Refrigerated Van
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(a)

(b)

(c)

Figure 2-25 Impact of (a) Delta CDA, (b) Delta CRR, and (c) Weight Reduction on CO2 Results of a GEMSimulated Short Dry Van
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(a)

(b)

(c)

Figure 2-26 Impact of (a) Delta CDA, (b) Delta CRR, and (c) Weight Reduction on CO2 Results of a GEMSimulated Short Refrigerated Van
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Additional GEM simulations were performed for each of the four box trailer 

subcategories to assess the combined effect of these parameters. As seen in Figure 2-27 and 

Figure 2-28 for the long dry van simulation, the coefficients of the curve fit equations did not 

change, indicating that the combined impacts of these parameters on GEM’s CO2 results were 

additive. Similar trends were seen with the simulations for the other trailer subcategories, though 

the results are not shown here. 

Figure 2-27 Combined Impact of Drag Area and Tire Rolling Resistance Level on CO2 Results of a GEMSimulated Long Dry Van with No Weight Reduction

Figure 2-28 Combined Impact of Drag Area and Weight Reduction on CO2 Results of a GEM-Simulated 

Long Dry Van at a Tire Rolling Resistance Level of 5.1 kg/ton

The results presented Figure 2-27 and Figure 2-28 suggest that these parameters could be 

combined into a single equation to calculate CO2 emissions. Equation 1 is the result of 

combining the curve fit equations for long box dry vans. 
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 = 87.6 − 6.1(∆) − 1.7(∆) − 0.001() (1)

Our proposed regulations specify that TRRL be an absolute measure of a tire’s 

coefficient of rolling resistance (not a change in rolling resistance). As a result, Equation 1 was 

modified such that the variables of the equation matched the trailer inputs required by GEM. 

Equation 2 is the resulting equation. 

 = 77.4 − 6.1(∆) + 1.7() − 0.001() (2)

Each of the trailer subcategories follows the same general format and a generic equation 

is shown in Equation 3. Table 2-94 summarizes the corresponding constants for each of the 

trailer subcategories. 

 =  + 

(∆) + () + () (3)

Table 2-94 Constants for GEM-Based CO2 Equation for Trailer Subcategories (See Equation 3)

TRAILER SUBCATEGORY C1 C2 C3 C4

Long Dry Van 77.4 -6.1 1.7 -0.001

Long Refrigerated Van 78.3 -6.0 1.8 -0.001

Short Dry Van 134.0 -10.5 2.2 -0.003

Short Refrigerated Van 136.3 -10.3 2.4 -0.003

Over 100 GEM vehicle simulations were performed for a range of delta CDA, TRRL and 

weight reduction values. The results of these simulations were compared to CO2 results 

calculated using Equation 3 for each trailer subcategory. The following figures show the 

equation and GEM have nearly identical CO2 results. 
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Figure 2-29 Comparison of GEM and Calculated CO2 Results for a Long Dry Van

Figure 2-30 Comparison of GEM and Calculated CO2 Results for a Long Refrigerated Van
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Figure 2-31 Comparison of GEM and Calculated CO2 Results for a Short Dry Van

Figure 2-32 Comparison of GEM and Calculated CO2 Results for a Short Refrigerated Van
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The comparisons shown in Figure 2-29 through Figure 2-32 suggest that an equation may

offer a simplified approach for trailer manufacturers to calculate CO2 without the use of GEM. 

Equation 4 below is a slight modification to Equation 3. The constants shown in Table 2-94 and 

used in Equation 3 were rearranged slightly to place the tire rolling resistance effect at the 

beginning of the equation, since we anticipate most trailers would adopt LRR tires. Equation 4 

and the corresponding Table 2-95 illustrate the rearrangement. As mentioned previously, the 

proposed trailer program is also offering the use of automatic tire inflation (ATI) systems as a 

means achieving the proposed standards. This parameter is not considered in Equation 3. 

Equation 4 includes a constant, C5, to address the use of ATI. Constant C5 is equal to unity for 

trailers that do not have ATI systems installed and equal to 0.985 (accounting for the 1.5% 

reduction assigned to ATI) for trailers that do include ATI systems. As mentioned previously, 

one can use a conversion factor of 10,180 grams CO2 per gallon of diesel fuel to calculate the 

corresponding fuel consumption values.

 = [ +  ∙ () +  ∙ (∆) +  ∙ ()] ∙ 

(4)

Table 2-95 Constants for GEM-Based CO2 Equation for Trailer Subcategories (See Equation 4)

TRAILER SUBCATEGORY C1 C2 C3 C4

Long Dry Van 77.4 1.7 -6.1 -0.001

Long Refrigerated Van 78.3 1.8 -6.0 -0.001

Short Dry Van 134.0 2.2 -10.5 -0.003

Short Refrigerated Van 136.3 2.4 -10.3 -0.003

2.11 Natural Gas 

2.11.1 Sealed Crankcase

EPA regulations allow venting to the atmosphere crankcase emissions from compressionignition engines, provided these vented crankcase emissions are measured and accounted for as 

part of an engine’s tailpipe emissions. This allowance has historically been in place to address 

the technical limitations related to recirculating diesel-fueled engines’ crankcase emissions, 

which have high PM emissions, back into the engine’s air intake. High PM emissions vented 

into the intake of an engine can foul turbocharger compressors and after-cooler heat exchangers. 

In contrast, historically EPA has mandated closed crankcase technology on all gasoline-fueled 

engines and all natural gas engines certified as spark-ignition. The inherently low PM emissions 

from these engines posed no technical barrier to a closed crankcase mandate. Because natural 

gas-fueled compression ignition engines also have inherently low PM emissions, there is no 

technological limitation that would prevent manufacturers from closing the crankcase and 

recirculating all crankcase gases into a natural gas-fueled compression ignition engine’s air 

intake. It is expected that costs for this requirement would be negligible. 
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2.11.2 Require 5 Day Hold Time

Boil-off emissions from LNG vehicles were not addressed in the Phase 1 rulemaking. 

However, it is our understanding that the majority or all of the NG vehicles are already 

compliant with National Fire Protection Association standard NFPA 52 and the similar SAE 

standard SAE J2343, which are recommended practices for 3 and 5 day hold times, respectively. 

These are very similar to one another, but the SAE standards calls for more rigorous control. 

Although these standards were developed largely to address fire safety issues (boil-off emissions 

can lead to explosive mixtures in enclosed spaces), it is clear that following the industry

recommended practice spelled out in SAE J2343 for five day hold time would substantially limit 

boil-off emissions from LNG vehicles. Therefore, EPA is proposing to require compliance with 

SAE J2343 as part of certification for LNG vehicles. Since the majority or all of the NG 

vehicles are already compliant with these requirements, there would be negligible costs

associated with the requirement for 5 day hold time based on the SAE standard practice.

2.12 Technology Costs

2.12.1 Overview of Technology Cost Methodology Learning Effects on 

Technology Costs

Section 2.12.1.2 presents the methods used to address indirect costs in this analysis. 

Section 2.12.1.3 presents the learning effects applied throughout this analysis. In Section 2.12.2

through 2.12.10 we present individual technology costs including: the direct manufacturing costs 

(DMC), their indirect costs (IC) and their total costs (TC, TC=DMC+IC). Note that we also 

present technology adoption rates for most technologies and the resultant total cost as applied to 

a technology package (which we have denoted as TCp, where TCp=TC x Adoption Rate). The 

tables presented show the adoption rate for, generally, alternatives 1a and 3 where 1a represents 

the reference case (or the “no action” case) and 3 represents the preferred policy case. For TCp 

values under alternative 4, one would replace the alternative 3 adoption rates with the 

appropriate alternative 4 adoption rates to arrive at the TCp costs under alternative 4. Note also 

that some TCp values appear as negative values in some tables (notably the lower rolling 

resistance (LRR) tire tables). This is because certain LRR tires are expected in the reference 

case but are then expected to be removed in the policy case and replaced by more aggressive 

LRR tires. In such cases, the reference case tires show negative TCp costs since they are being 

removed and replaced.

2.12.1.1 Direct Manufacturing Costs

The direct manufacturing costs (DMCs) used throughout this analysis are derived from 

several sources. Many of the tractor, vocational and trailer DMCs can be sourced to the Phase 1 

rules which, in turn, were sourced largely from a contracted study by ICF International for 

EPA.164 There was no serious disagreement regarding these estimated costs in the public 

comments to the Phase 1 rules. We have updated those costs by converting them to 2012 dollars, 

as described in Section IX.B.1.e of the Preamble, and by continuing the learning effects 

described in the Phase 1 rules and in Section IX. B.1.c of the Preamble. The new tractor, 

vocational and trailer costs can be sourced to a more recent study conducted by Southwest 

Research Institute (SwRI) under contract to NHTSA.165 The cost methodology used by SwRI in 
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that study was to estimate retail costs then work backward from there to derive a DMC for each 

technology. The agencies did not agree with the approach used by Tetra Tech to move from 

retail cost to DMC. As such, the agencies have used an approach consistent with past 

GHG/CAFE/fuel consumption rules by dividing estimated retail prices by our estimated retail 

price equivalent markups to derive an appropriate DMC for each technology. We describe our 

RPEs in Section 2.12.1.2. 

For HD pickups and vans, we have relied primarily on the Phase 1 rules and the lightduty 2017-2025 model year rule since most technologies expected on these vehicles are, in 

effect, the same as those used on light-duty pickups. Many of those technology DMCs are based 

on cost teardown studies which the agencies consider to be the most robust method of cost 

estimation. However, many of the HD versions of those technologies would be expected to be 

more costly than their light-duty counterparts because of the heavier HD vehicles and/or the 

higher power and torque characteristics of their engines. Therefore, we have scaled upward 

where appropriate many of the light-duty DMCs for this analysis. We have also used some costs 

developed under contract to NHTSA by SwRI (the study mentioned above).166 

Importantly, in our methodology, all technologies are treated as being sourced from a 

supplier rather than being developed and produced in-house. As such, some portion of the total 

indirect costs of making a technology or system—those costs incurred by the supplier for 

research, development, transportation, marketing etc.—are contained in the sales price to the 

engine and/or vehicle/trailer manufacturer (i.e., the original equipment manufacturer (OEM)). 

That sale price paid by the OEM to the supplier is the DMC we estimate. 

2.12.1.2 Indirect Costs

To produce a unit of output, engine and truck manufacturers incur direct and indirect 

costs. Direct costs include cost of materials and labor costs. Indirect costs are all the costs 

associated with producing the unit of output that are not direct costs – for example, they may be 

related to production (such as research and development [R&D]), corporate operations (such as 

salaries, pensions, and health care costs for corporate staff), or selling (such as transportation, 

dealer support, and marketing). Indirect costs are generally recovered by allocating a share of 

the costs to each unit of good sold. Although it is possible to account for direct costs allocated to 

each unit of good sold, it is more challenging to account for indirect costs allocated to a unit of 

goods sold. To make a cost analysis process more feasible, markup factors, which relate total 

indirect costs to total direct costs, have been developed. These factors are often referred to as 

retail price equivalent (RPE) multipliers.

Cost analysts and regulatory agencies (including both EPA and NHTSA) have frequently

used these multipliers to predict the resultant impact on costs associated with manufacturers’ 

responses to regulatory requirements. The best approach, if it were possible, to determining the 

impact of changes in direct manufacturing costs on a manufacturer’s indirect costs would be to 

actually estimate the cost impact on each indirect cost element. However, doing this within the 

constraints of an agency’s time or budget is not always feasible, or the technical, financial, and 

accounting information to carry out such an analysis may simply be unavailable. 
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RPE multipliers provide, at an aggregate level, the relative shares of revenues (Revenue = 

Direct Costs + Indirect Costs + Net Income) to direct manufacturing costs. Using RPE 

multipliers implicitly assumes that incremental changes in direct manufacturing costs produce 

common incremental changes in all indirect cost contributors as well as net income. However, a

concern in using the RPE multiplier in cost analysis for new technologies added in response to 

regulatory requirements is that the indirect costs of vehicle modifications are not likely to be the 

same for different technologies. For example, less complex technologies could require fewer 

R&D efforts or less warranty coverage than more complex technologies. In addition, some 

simple technological adjustments may, for example, have no effect on the number of corporate 

personnel and the indirect costs attributable to those personnel. The use of RPEs, with their 

assumption that all technologies have the same proportion of indirect costs, is likely to 

overestimate the costs of less complex technologies and underestimate the costs of more 

complex technologies. Table 2-96 shows the RPE factors used in developing indirect costs in 

past, and this, agency analyses.

Table 2-96 Industry Retail Price Equivalent (RPE) Factors

INDUSTRY RPE

Heavy engine manufacturers 1.28

Heavy truck manufacturers 1.36

Light-duty vehicle manufacturers 1.50

To address this concern, modified multipliers have been developed by EPA, working 

with a contractor, for use in rulemakings. These multipliers are referred to as indirect cost 

multipliers (or ICMs). In contrast to RPE multipliers, ICMs assign unique incremental changes 

to each indirect cost contributor as well as net income.

ICM = (direct cost + adjusted indirect cost)/(direct cost)

Developing the ICMs from the RPE multipliers requires developing adjustment factors 

based on the complexity of the technology and the time frame under consideration: the less 

complex a technology, the lower its ICM, and the longer the time frame for applying the 

technology, the lower the ICM. This methodology was used in the cost estimation for the recent

light-duty MYs 2012-2016 and MYs 2017-2025 rulemaking and for the heavy-duty MYs 2014-

2018 rulemaking. There was no serious disagreement with this approach in the public comments 

to any of these rulemakings. The ICMs for the light-duty context were developed in a peerreviewed report from RTI International and were subsequently discussed in a peer-reviewed 

journal article.167 Importantly, since publication of that peer-reviewed journal article, the 

agencies have revised the methodology to include a return on capital (i.e., profits) based on the 

assumption implicit in ICMs (and RPEs) that capital costs are proportional to direct costs, and 

businesses need to be able to earn returns on their investments. 

For the heavy-duty pickup truck and van cost projections in this proposal, the agencies 

have used ICM adjustment factors developed for light-duty vehicles, inclusive of a return on 

capital, primarily because the manufacturers involved in this segment of the heavy-duty market 

are the same manufacturers that build light-duty trucks. 
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For the combination tractors, vocational vehicles, and heavy-duty engine cost projections 

in this proposal, the agencies are again using the ICMs used in the HD Phase 1 rules. Those 

ICMs were developed by RTI International under EPA contract to update EPA’s methodology

for accounting for indirect costs associated with changes in direct manufacturing costs for heavyduty engine and truck manufacturers.168

 In addition to the indirect cost contributors varying by

complexity and time frame, there is no reason to expect that the contributors would be the same 

for engine manufacturers as for truck manufacturers. The resulting report from RTI provides a 

description of the methodology, as well as calculations of the indirect cost multipliers that are 

being used as the basis for the markups used in this proposal. These indirect cost multipliers 

were used, along with calculations of direct manufacturing costs, to provide estimates of the full 

additional costs associated with new technologies. 

As explained in the Phase 1 final rules, and entirely consistent with the analysis 

supporting that program, the agencies have made some changes to both the ICMs factors and to 

the method of applying those factors relative to the factors developed by RTI and presented in 

their reports. The first of these changes was done in response to continued thinking among the 

agencies about how past ICMs have been developed and what are the most appropriate data 

sources to rely upon in determining the appropriate ICMs. The second change was done in 

response to both staff concerns and public feedback suggesting that the agencies were 

inappropriately applying learning effects to indirect costs via the multiplicative approach to 

applying the ICMs.

Regarding the first change – to the ICM factors themselves – a little background must 

first be provided. In the original work done under contract to EPA by RTI International,169 EPA 

experts had undergone a consensus approach to determining the impact of specific technology

changes on the indirect costs of a company. Subsequent to that effort, EPA experts underwent a 

blind survey to make this determination on a different set of technology changes. This 

subsequent effort, referred to by EPA as a modified-Delphi approach, resulted in different ICM 

determinations. This effort is detailed in a memorandum contained in the docket for this 

rulemaking.170 Upon completing this effort, EPA determined that the original RTI values should 

be averaged with the modified-Delphi values to arrive at the final ICMs for low and medium 

complexity technologies and that the original RTI values would be used for high complexity

level 1 while the modified-Delphi values would be used for high complexity level 2. These final 

ICMs were used in the 2012-2016 light-duty GHG/CAFE rulemaking. Subsequent to that, EPA 

contracted RTI to update their light-duty report with an eye to the heavy-duty industry. In that 

effort, RTI determined the RPE of both the heavy-duty engine and heavy truck industries, then 

applied the light-duty indirect cost factors—those resulting from the averaging of the values 

from their original report with the modified-Delphi values—to the heavy-duty RPEs to arrive at 

heavy-duty specific ICMs. That effort is described in their final heavy-duty ICM report 

mentioned above.171

During development of the Phase 1 heavy-duty final rules, the agencies decided that the 

original light-duty RTI values, given the technologies considered for low and medium 

complexity, should no longer be used and that we should rely solely on the modified-Delphi 

values for these complexity levels. The original light-duty RTI study used low rolling resistance 

tires as a low complexity technology example and a dual clutch transmission as a medium 

complexity technology. Upon further thought, the technologies considered for the modified 
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Delphi values (passive aerodynamic improvements for low complexity and turbocharging with 

downsizing for medium complexity were considered to better represent the example 

technologies). As a result, the modified-Delphi values were to become the working ICMs for 

low and medium complexity rather than averaging those values with the original RTI report 

values. The agencies have also re-examined the technology complexity categories that were 

assigned to each light-duty technology and modified these assignments to better reflect the 

technologies that are now used as proxies for each category. This decision impacted the low and 

medium complexity heavy-duty ICMs too because the modified-Delphi values alone were to be 

applied to the heavy-duty RPEs to arrive at heavy-duty ICMs rather than using the averaged 

values developed for the light-duty 2012-2016 rulemaking. 

A secondary-level change was also made as part of this ICM recalculation to the lightduty ICMs and, therefore, to the ICMs used in the Phase 1 HD final rules and again in this 

proposed analysis for HD pickups and vans. That change was to revise upward the RPE level 

reported in the original RTI report from an original value of 1.46 to 1.5 to reflect the long term 

average RPE. The original RTI study was based on 2008 data. However, an analysis of 

historical RPE data indicates that, although there is year to year variation, the average RPE has 

remained roughly 1.5. ICMs are applied to future year’s data and therefore the agencies believed 

and continue to believe that it is most appropriate to base ICMs on the historical average rather 

than a single year’s result. Therefore, ICMs were adjusted to reflect this average level. As a 

result, the High 1 and High 2 ICMs used for HD pickups and vans were changed for the Phase 1 

final rules and we continue to use those changed values here.

Table 2-97 shows the ICM values used in this proposal. Near term values are used in 

early years, depending on the technology, and account for differences in the levels of R&D, 

tooling, and other indirect costs that would be incurred. Once the program has been fully 

implemented, some of the indirect costs would no longer be attributable to the standards and, as 

such, a lower ICM factor is applied to direct costs in later years.

Table 2-97 Indirect Cost Multipliers Used in this Analysisa

CLASS COMPLEXITY NEAR 

TERM

LONG 

TERM

HD Pickup Trucks and Vans Low 1.24 1.19

Medium 1.39 1.29

High1 1.56 1.35

High2 1.77 1.50

Loose diesel engines Low 1.15 1.13

Medium 1.24 1.18

High1 1.28 1.19

High2 1.44 1.29

Loose gasoline engines Low 1.24 1.19

Medium 1.39 1.29

High1 1.56 1.35

High2 1.77 1.50

Vocational Vehicles, 

Combination Tractors and 

Trailers

Low 1.18 1.14

Medium 1.30 1.23

High1 1.43 1.27
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High2 1.57 1.37

Note:

a Rogozhin, A., et. al., “Using indirect cost multipliers to estimate the total cost of adding 

new technology in the automobile industry,” International Journal of Production 

Economics (2009); “Documentation of the Development of Indirect Cost Multipliers for 

Three Automotive Technologies,” Helfand, G., and Sherwood, T., Memorandum dated 

August 2009; “Heavy Duty Truck Retail Price Equivalent and Indirect Cost Multipliers,” 

Draft Report prepared by RTI International and Transportation Research Institute, 

University of Michigan, July 2010.

The second change made to the ICMs during development of the Phase 1 final rules had 

to do with the way in which the ICMs were applied. Until that time, we had applied the ICMs, 

as done in any analysis that relied on RPEs, as a pure multiplicative factor. This way, a direct 

manufacturing cost of, say, $100 would have been multiplied by an ICM of 1.24 to arrive at a 

marked up technology cost of $124. However, as learning effects (discussed below) are applied 

to the direct manufacturing cost, the indirect costs are also reduced accordingly. Therefore, in 

year 2 the $100 direct manufacturing cost might reduce to $97 and the marked up cost would 

become $120 ($97 x 1.24). As a result, indirect costs have been reduced from $24 to $23. Given 

that indirect costs cover many things such as facility-related costs, electricity, etc., it is perhaps 

not appropriate to apply the ICM to the learned direct costs, at least not for those indirect cost 

elements unlikely to change with learning. The agencies decided that it was more appropriate 

only to allow warranty costs to decrease with learning since warranty costs are tied to direct 

manufacturing costs (since warranty typically involves replacement of actual parts which should 

be less costly with learning).Q However, the remaining elements of the indirect costs should 

remain constant year-over-year, at least until some of those indirect costs are no longer 

attributable to the rulemaking effort that imposed them (such as R&D).

As a result, the ICM calculation became more complex with the analysis supporting the 

Phase 1 final rules, and we continue to use that more complex calculation here. We first 

establish the year in which the direct manufacturing costs are considered “valid.” For example, a 

cost estimate might be considered valid today, or perhaps not until high volume production is 

reached in some future model year. That year is considered the base year for the estimated cost. 

That cost is the cost used to determine the “non-warranty” portion of the indirect costs. For 

example, the near term non-warranty portion of the loose diesel engine low complexity ICM is 

0.149 (the warranty versus non-warranty portions of the ICMs are shown in Table 2-98). For the 

improved water pump technology we have estimated a direct manufacturing cost of $82.66 

(2012$) in MY 2014. So the non-warranty portion of the indirect costs would be $12.32 ($82.66 

x 0.149). This value would be added to the learned direct manufacturing cost for each year 

through 2022 since the near term markup is considered appropriate for that technology through 

2022. Beginning in 2023, when long-term indirect costs begin, the additive factor would become 

$10.08 ($82.66 x 0.122). Additionally, the $82.66 cost in 2014 would become $80.18 in MY 

2015 due to learning ($82.66 x (1-3 percent)). So, while the warranty portion of the indirect 

costs would be $0.49 ($82.66 x 0.006) in 2014, they would decrease to $0.48 ($80.18 x 0.006) in 

2015 as warranty costs decrease with learning. The resultant indirect costs for the water pump 

 

Q We note that the labor portion of warranty repairs does not decrease due to learning. However, we do not have 

data to separate this portion and so we apply learning to the entire warranty cost. Because warranty costs are a small 

portion of overall indirect costs, this has only a minor impact on the analysis.
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would be $12.81 ($12.32+$0.49) in MY 2014 and $12.80 ($12.32+$0.48) in MY2015, and so on 

for subsequent years.

Importantly, since the bulk of the indirect costs calculated using this methodology are the 

non-warranty costs, and since those costs do not change over with learning, one cannot look at 

the ICMs shown in Table 2-97 and assume that our HD pickup and van total costs are, in general, 

1.24 or 1.39 times the direct costs (since most technologies considered for application in HD 

pickups and vans are low and medium technologies). This can be illustrated by building on the 

example presented above for a water pump on a heavy diesel engine. We already calculated the 

MY 2014 total cost as $95.46 (2012$, $82.66+$12.32+$0.49). This is an effective markup of 

1.155 ($95.46/$82.66). This is expected since the cost is based in 2014 and the near term ICM is 

1.155. In MY2022, the final year of near term markups for this technology, the total cost would 

be $80.21 since the learned direct cost has reduced to $67.50, the non-warranty indirect costs 

(calculated above) remain $12.32, and the warranty indirect costs have become $0.39 

($67.50x0.006). So, in MY2022, we now have an effective markup of 1.19 ($80.21/$67.50).

Table 2-98 Warranty and Non-Warranty Portions of ICMs

SHORT-TERM LONG-TERM

CLASS COMPLEXITY WARRANTY NONWARRANTYWARRANTY NONWARRANTY

HD Pickup and 

Vans

Low 0.012 0.230 0.005 0.187

Medium 0.045 0.343 0.031 0.259

High1 0.065 0.499 0.032 0.314

High2 0.074 0.696 0.049 0.448

Loose diesel 

engines

Low 0.006 0.149 0.003 0.122

Medium 0.022 0.213 0.016 0.165

High1 0.032 0.249 0.016 0.176

High2 0.037 0.398 0.025 0.265

Loose gasoline 

engines

Low 0.012 0.230 0.005 0.187

Medium 0.045 0.343 0.031 0.259

High1 0.065 0.499 0.032 0.314

High2 0.074 0.696 0.049 0.448

Vocational 

Vehicles, 

Combination 

Tractors and 

Trailers

Low 0.013 0.165 0.006 0.134

Medium 0.051 0.252 0.035 0.190

High1 0.073 0.352 0.037 0.233

High2 0.084 0.486 0.056 0.312

The complexity levels and subsequent ICMs applied throughout this analysis for each 

technology are shown in Table 2-99.

Table 2-99 Indirect Cost Markups and Near Term/Long Term Cutoffs Used in this Analysis

TECHNOLOGY APPLIED TO ICM 

COMPLEXITY

NEAR TERM 

THRU

Cylinder head improvements 1 LH/MH/HH Engines Low 2022

Cylinder head improvements 2 LH/MH/HH Engines Low 2027

Turbo efficiency improvements 1 LH/MH/HH, HD Pickup & 

Van Engines

Low 2022

Turbo efficiency improvements 2 LH/MH/HH Engines Low 2027

EGR cooler efficiency improvements 1 LH/MH/HH Engines Low 2022
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EGR cooler efficiency improvements 2 LH/MH/HH Engines Low 2027

Water pump improvements 1 LH/MH/HH Engines Low 2022

Water pump improvements 2 LH/MH/HH Engines Low 2027

Oil pump improvements 1 LH/MH/HH Engines Low 2022

Oil pump improvements 2 LH/MH/HH Engines Low 2027

Fuel pump improvements 1 LH/MH/HH Engines Low 2022

Fuel pump improvements 2 LH/MH/HH Engines Low 2027

Fuel rail improvements 1 LH/MH/HH Engines Low 2022

Fuel rail improvements 2 LH/MH/HH Engines Low 2027

Fuel injector improvements 1 LH/MH/HH Engines Low 2022

Fuel injector improvements 2 LH/MH/HH Engines Low 2027

Piston improvements 1 LH/MH/HH Engines Low 2022

Piston improvements 2 LH/MH/HH Engines Low 2027

Valve train friction reductions 1 LH/MH/HH Engines Low 2022

Valve train friction reductions 2 LH/MH/HH Engines Low 2027

Turbo compounding 1 LH/MH/HH Engines Low 2022

Turbo compounding 2 LH/MH/HH Engines Low 2027

Aftertreatment improvements 1 LH/MH/HH Engines Low 2022

Aftertreatment improvements 2 LH/MH/HH Engines Low 2024

Model based control LH/MH/HH Engines Low 2022

Waste heat recovery HH Engines Medium 2025

Engine friction reduction 1 HD Pickup & Van Engines Low 2018

Engine friction reduction 2 HD Pickup & Van Engines Low 2024

Engine changes to accommodate low friction 

lubes

HD Pickup & Van Engines Low 2018

Variable valve timing – coupled HD Pickup & Van Engines Low 2018

Variable valve timing – dual HD Pickup & Van Engines Medium 2018

Stoichiometric gasoline direct injection HD Pickup & Van Engines Medium 2018

Cylinder deactivation HD Pickup & Van Engines Medium 2018

Cooled EGR HD Pickup & Van Engines Medium 2024

Turbocharging & downsizing HD Pickup & Van Engines Medium 2018

“Right sized” diesel engine HD Pickup & Van vehicles, 

Tractors

Low 2022

6 speed transmission HD Pickup & Van vehicles Medium 2018

8 speed transmission HD Pickup & Van vehicles, 

Vocational

Medium 2018

Automated manual transmission (AMT) Vocational, Tractors Medium 2022

Auto transmission, power-shift Tractors Medium 2022

Conversion from manual to auto trans Vocational Medium 2018

Dual clutch transmission Vocational, Tractors Medium 2022

Improved transmission Vocational Low 2022

Lower RR tires 1 HD Pickup & Van vehicles Low 2018

Lower RR tires 2 HD Pickup & Van vehicles Low 2024

Low drag brakes HD Pickup & Van vehicles Low 2018

Electric power steering HD Pickup & Van vehicles Low 2018

High efficiency transmission HD Pickup & Van vehicles Low 2024

Driveline friction reduction HD Pickup & Van vehicles Low 2022

Improved accessories (electrification) HD Pickup & Van vehicles Low 2018

Improved accessories (electrification) Tractors Low 2022

Improved fan Tractors Low 2022

Lower RR tires 1 Vocational , Tractors, 

Trailers

Low 2022

Lower RR tires 2 Vocational , Tractors, 

Trailers

Low 2022

Lower RR tires 3 Vocational , Tractors, 

Trailers s

Medium 2025

Lower RR tires 4 Vocational , Tractors, 

Trailers

Medium 2028
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Automated Tire Inflation System (ATIS) Tractors, Trailers Low 2022

Aero 1 HD Pickup & Van vehicles Low 2018

Aero 2 HD Pickup & Van vehicles Medium 2024

Aero Bins 1 thru 4 Tractors Low 2022

Aero Bin 5 thru 7 Tractors Medium 2025

Aero Bins 1 thru 8 Trailers Low 2018

Weight reduction (via single wide tires and/or 

aluminum wheels)

Tractors Low 2022

Weight reduction via material changes HD Pickup & Van vehicles Low 2018

Weight reduction via material changes – 200 

lbs, 400 lbs

Vocational Low 2022

Weight reduction via material changes – 1000 

lbs

Vocational Medium 2022

Weight reduction via material changes Tractors Low 2022

Auxiliary power unit Tractors Low 2022

Air conditioning leakage Vocational, Tractors Low 2022

Air conditioning efficiency Tractors Low 2022

Neutral idle Vocational Low 2022

Stop-start (no regeneration) HD Pickup & Van vehicles Medium 2018

Stop-start (no regeneration) Vocational Medium 2022

Mild hybrid HD Pickup & Van vehicles High1 2024

Mild hybrid Tractors High1 2025

Strong hybrid HD Pickup & Van vehicles High1 2024

Strong hybrid Vocational High1 2022

Full electric Vocational, Tractors High1 2028

There is some level of uncertainty surrounding both the ICM and RPE markup factors. 

The ICM estimates used in this proposal group all technologies into three broad categories and 

treat them as if individual technologies within each of the three categories (low, medium, and 

high complexity) would have the same ratio of indirect costs to direct costs. This simplification 

means it is likely that the direct cost for some technologies within a category will be higher and 

some lower than the estimate for the category in general. More importantly, the ICM estimates 

have not been validated through a direct accounting of actual indirect costs for individual 

technologies. RPEs themselves are inherently difficult to estimate because the accounting 

statements of manufacturers do not neatly categorize all cost elements as either direct or indirect 

costs. Hence, each researcher developing an RPE estimate must apply a certain amount of 

judgment to the allocation of the costs. Moreover, RPEs for heavy- and medium-duty trucks and 

for engine manufacturers are not as well studied as they are for the light-duty automobile 

industry. Since empirical estimates of ICMs are ultimately derived from the same data used to 

measure RPEs, this affects both measures. However, the value of RPE has not been measured 

for specific technologies, or for groups of specific technologies. Thus, even if we assume that 

the examined technology accurately represents the average impact on all technologies in its 

representative category, applying a single average RPE to any given technology by definition 

overstates costs for very simple technologies, or understates them for more advanced 

technologies in that group. 

2.12.1.3 Learning Effects on Technology Costs

For some of the technologies considered in this analysis, manufacturer learning effects 

would be expected to play a role in the actual end costs. The “learning curve” or “experience 

curve” describes the reduction in unit production costs as a function of accumulated production 
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volume. In theory, the cost behavior it describes applies to cumulative production volume 

measured at the level of an individual manufacturer, although it is often assumed—as both 

agencies have done in past regulatory analyses—to apply at the industry-wide level, particularly

in industries that utilize many common technologies and component supply sources. Both 

agencies believe there are indeed many factors that cause costs to decrease over time. Research 

in the costs of manufacturing has consistently shown that, as manufacturers gain experience in 

production, they are able to apply innovations to simplify machining and assembly operations, 

use lower cost materials, and reduce the number or complexity of component parts. All of these 

factors allow manufacturers to lower the per-unit cost of production (i.e., the manufacturing 

learning curve).172

The agencies have a detailed description of the learning effect in the light-duty 2012-

2016 rulemaking. Most studies of the effect of experience or learning on production costs appear 

to assume that cost reductions begin only after some initial volume threshold has been reached, 

but not all of these studies specify this threshold volume. The rate at which costs decline beyond 

the initial threshold is usually expressed as the percent reduction in average unit cost that results 

from each successive doubling of cumulative production volume, sometimes referred to as the 

learning rate. Many estimates of experience curves do not specify a cumulative production 

volume beyond which cost reductions would no longer occur, instead depending on the 

asymptotic behavior of the effect for learning rates below 100 percent to establish a floor on 

costs. 

In past rulemaking analyses, as noted above, both agencies have used a learning curve 

algorithm that applied a learning factor of 20 percent for each doubling of production volume. 

NHTSA has used this approach in analyses supporting recent CAFE rules. In its analyses, EPA 

has simplified the approach by using an “every two years” based learning progression rather than 

a pure production volume progression (i.e., after two years of production it was assumed that 

production volumes would have doubled and, therefore, costs would be reduced by 20 percent).

In the light-duty 2012-2016 rulemaking, the agencies employed an additional learning 

algorithm to reflect the volume-based learning cost reductions that occur further along on the 

learning curve. This additional learning algorithm was termed “time-based” learning simply as a 

means of distinguishing this algorithm from the volume-based algorithm mentioned above, 

although both of the algorithms reflect the volume-based learning curve supported in the 

literature.173 To avoid confusion, we now refer to this learning algorithm as the “flat-portion” of 

the learning curve. This way, we maintain the clarity that all learning is, in fact, volume-based 

learning, and the level of cost reductions depend only on where on the learning curve a 

technology’s learning progression is. We distinguish the flat-portion of the curve from the steepportion of the curve to indicate the level of learning taking place in the years following 

implementation of the technology. The agencies have applied the steep-portion learning 

algorithm for those technologies considered to be newer technologies likely to experience rapid 

cost reductions through manufacturer learning and the flat-portion learning algorithm for those 

technologies considered to be mature technologies likely to experience minor cost reductions 

through manufacturer learning. As noted above, the steep-portion learning algorithm results in 

20 percent lower costs after two full years of implementation (i.e., the 2016 MY costs are 20 

percent lower than the 2014 and 2015 model year costs). Once the steep-portion learning steps 

have occurred (for technologies having the steep-portion learning algorithm applied), flat-portion 
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learning at 3 percent per year becomes effective for 5 years. For technologies having the flatportion learning algorithm applied), flat-portion learning at 3 percent per year begins in year 2 

and remains effective for 5 years. Beyond 5 years of learning at 3 percent per year, 5 years of 

learning at 2 percent per year, then 5 at 1 percent per year become effective. There was no 

serious disagreement with this approach in the public comments to any of the GHG/fuel 

economy/consumption rulemakings. 

Learning effects are applied to most but not all technologies because some of the 

expected technologies are already used rather widely in the industry and, presumably, learning 

impacts have already occurred. The steep-portion learning algorithm was applied for only a 

handful of technologies that are considered to be new or emerging technologies. Most 

technologies have been considered to be more established given their current use in the fleet and, 

hence, the lower flat-portion learning algorithm has been applied. The learning algorithms 

applied to each technology are summarized in Table 2-100.

Table 2-100 Learning Effect Algorithms Applied to Technologies Used in this Analysis

TECHNOLOGY APPLIED TO LEARNING 

ALGORITHM

LEARNING 

FACTOR 

“CURVE” A

Cylinder head improvements 1 LH/MH/HH Engines Flat 2

Cylinder head improvements 2 LH/MH/HH Engines Flat 13

Turbo efficiency improvements 1 LH/MH/HH, HD Pickup 

& Van Engines

Flat 2

Turbo efficiency improvements 2 LH/MH/HH Engines Flat 13

EGR cooler efficiency improvements 1 LH/MH/HH Engines Flat 2

EGR cooler efficiency improvements 2 LH/MH/HH Engines Flat 13

Water pump improvements 1 LH/MH/HH Engines Flat 2

Water pump improvements 2 LH/MH/HH Engines Flat 13

Oil pump improvements 1 LH/MH/HH Engines Flat 2

Oil pump improvements 2 LH/MH/HH Engines Flat 13

Fuel pump improvements 1 LH/MH/HH Engines Flat 2

Fuel pump improvements 2 LH/MH/HH Engines Flat 13

Fuel rail improvements 1 LH/MH/HH Engines Flat 2

Fuel rail improvements 2 LH/MH/HH Engines Flat 13

Fuel injector improvements 1 LH/MH/HH Engines Flat 2

Fuel injector improvements 2 LH/MH/HH Engines Flat 13

Piston improvements 1 LH/MH/HH Engines Flat 2

Piston improvements 2 LH/MH/HH Engines Flat 13

Valve train friction reductions 1 LH/MH/HH Engines Flat 2

Valve train friction reductions 2 LH/MH/HH Engines Flat 13

Turbo compounding 1 LH/MH/HH Engines Flat 2

Turbo compounding 2 LH/MH/HH Engines Flat 13

Aftertreatment improvements 1 & 2 LH/MH/HH Engines Flat 2

Model based control LH/MH/HH Engines Flat 13

Waste heat recovery HH Engines Flat 12

Engine friction reduction 1 & 2 HD Pickup & Van 

Engines

None 1

Engine changes to accommodate low

friction lubes

HD Pickup & Van 

Engines

None 1

Variable valve timing HD Pickup & Van Flat 8
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Engines

Stoichiometric gasoline direct injection HD Pickup & Van 

Engines

Flat 7

Cylinder deactivation HD Pickup & Van 

Engines

Flat 8

Cooled EGR HD Pickup & Van 

Engines

Flat 7

Turbocharging & downsizing HD Pickup & Van 

Engines

Flat 7

“Right sized” diesel engine HD Pickup & Van 

vehicles, Tractors

None 1

6 speed transmission HD Pickup & Van 

vehicles

Flat 7

8 speed transmission HD Pickup & Van 

vehicles, Vocational

Flat 7

Automated manual transmission (AMT) Vocational, Tractors Flat 12

Auto transmission, power-shift Tractors Flat 12

Conversion from manual to auto trans Vocational Flat 7

Dual clutch transmission Vocational, Tractors Flat 12

Improved transmission Vocational Flat 13

Lower RR tires 1 HD Pickup & Van 

vehicles

None 1

Lower RR tires 2 HD Pickup & Van 

vehicles

Steep 11

Low drag brakes HD Pickup & Van 

vehicles

None 1

Electric power steering HD Pickup & Van 

vehicles

Flat 8

High efficiency transmission HD Pickup & Van 

vehicles

Flat 6

Driveline friction reduction HD Pickup & Van 

vehicles

Flat 3

Improved accessories (electrification) HD Pickup & Van 

vehicles

Flat 8

Improved accessories Tractors Flat 12

Improved fan Tractors Flat 12

Lower RR tires 1 Vocational , Tractors, 

Trailers

Flat 2

Lower RR tires 2 Vocational , Tractors, 

Trailers

Flat 2

Lower RR tires 3 Vocational , Tractors, 

Trailers

Flat 12

Lower RR tires 4 Vocational , Tractors, 

Trailers

Flat 13

Automated Tire Inflation System (ATIS) Tractors, Trailers Flat 12

Aero 1 & 2 HD Pickup & Van 

vehicles

Flat 8

Aero Bins 1 & 2 Tractors None 1

Aero Bin 3 Tractors Flat 2

Aero Bins 4 thru 7 Tractors Steep 4

Aero Bins 1 thru 8 Trailers Flat 2

Weight reduction (via single wide tires 

and/or aluminum wheels)

Tractors Flat 2
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Weight reduction via material changes HD Pickup & Van 

vehicles

Flat 6

Weight reduction via material changes Vocational, Tractors Flat 13

Auxiliary power unit Tractors Flat 2

Air conditioning leakage Vocational, Tractors Flat 2

Air conditioning efficiency Tractors Flat 12

Neutral idle Vocational None 1

Stop-start (no regeneration) HD Pickup & Van 

vehicles

Steep 9

Stop-start (no regeneration) Vocational Flat 13

Mild hybrid HD Pickup & Van 

vehicles

Flat 6

Mild hybrid Tractors Flat 12

Strong hybrid HD Pickup & Van 

vehicles, Vocational

Steep 11

Full electric Vocational, Tractors Steep 4

Note:

a

See table and figure below.

The actual year-by-year factors for the numbered curves shown in Table 2-100 are shown 

in Table 2-101 and are shown graphically in Figure 2-33.

Table 2-101 Year-by-year Learning Curve Factors for the Learning Curves Used in this Analysis

CURVEA2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025

1 1.000 1.000 1.000 1.000 1.000 1.000 1.000 1.000 1.000 1.000 1.000 1.000

2 1.000 0.970 0.941 0.913 0.885 0.868 0.850 0.833 0.817 0.800 0.784 0.769

3 1.031 1.000 0.970 0.941 0.913 0.894 0.877 0.859 0.842 0.825 0.808 0.792

4 1.000 1.000 0.800 0.800 0.640 0.621 0.602 0.584 0.567 0.550 0.533 0.517

6 1.096 1.063 1.031 1.000 0.970 0.941 0.913 0.885 0.859 0.842 0.825 0.808

7 0.941 0.913 0.885 0.868 0.850 0.833 0.817 0.800 0.784 0.769 0.753 0.738

8 1.031 1.000 0.970 0.951 0.932 0.913 0.895 0.877 0.859 0.842 0.825 0.809

9 1.250 1.000 1.000 0.970 0.941 0.913 0.885 0.859 0.833 0.808 0.784 0.760

11 1.563 1.563 1.563 1.563 1.563 1.250 1.250 1.000 0.970 0.941 0.913 0.885

12 1.130 1.096 1.063 1.031 1.000 0.970 0.941 0.913 0.894 0.877 0.859 0.842

13 1.238 1.201 1.165 1.130 1.096 1.063 1.031 1.000 0.970 0.941 0.913 0.894

Note:

a Curves 5 and 10 were generated but subsequently not used so are not included in the table.
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0.40

0.60

0.80

1.00

1.20

1.40

1.60

2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025

1

2

3

4

6

7

8

9

11

12

13

Figure 2-33 Year-by-year Learning Curve Factors for the Learning Curves used in this Analysis

Importantly, where the factors shown in Table 2-101 and, therefore, the curves shown in 

Figure 2-33 equal “1.00” represents the year for which any particular technology’s cost is based. 

In other words, for example, the cost estimate that we have for cylinder head improvements 2 is 

“based” in 2021 (curve 13). Therefore, its learning factor equals 1.00 in 2021 and then decreases 

going forward to represent lower costs due to learning effects. Its learning factors are greater 

than 1.00 in years before 2021 to represent “reverse” learning, i.e., higher costs than our 2021 

estimate since production volumes have, presumably, not yet reached the point where our cost 

estimate can be considered valid.

2.12.1.4 Technology Adoption Rates and Package Costs

Determining the stringency of the proposed standards involves a balancing of relevant 

factors – chiefly technology feasibility and effectiveness, costs, and lead time. For vocational 

vehicles, tractors and trailers, the agencies have projected a technology path to achieve the 

proposed standards reflecting an application rate of those technologies the agencies consider to 

be available at reasonable cost in the lead times provided. The agencies do not expect each of 

the technologies for which costs have been developed to be employed by all engines and vehicles 

across the board. Further, many of today’s vehicles are already equipped with some of the 

technologies and/or are expected to adopt them by MY2018 to comply with the HD Phase 1 

standards. Estimated adoption rates in both the reference and control cases are necessary for 

each vehicle/trailer category. The adoption rates for many technologies are zero in the reference 
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case; however, for some technologies—notably aero and tire technologies—the adoption rate is 

not always zero in the reference case. These reference and control case adoption rates are then

applied to the technology costs with the result being a package cost for each vehicle/trailer 

category. As such, package costs are rarely if ever a simple sum of all the technology costs since 

each technology would be expected to be adopted at different rates.

For HD pickups and vans, the CAFE model determines the technology adoption rates that 

most cost effectively meet the standards being proposed. Similar to vocational vehicles, tractors 

and trailers, package costs are rarely if ever a simple sum of all the technology costs since each 

technology would be expected to be adopted at different rates. The methods for estimating 

technology adoption rates and resultant costs (and other impacts) for HD pickups and vans are 

discussed in Chapter 10 of this draft RIA.

2.12.1.5 Conversion of Technology Costs to 2012 U.S. Dollars

As noted above in Section IX.C.1, the agencies are using technology costs from many

different sources. These sources, having been published in different years, present costs in 

different year dollars (i.e., 2009 dollars or 2010 dollars). For this analysis, the agencies sought to 

have all costs in terms of 2012 dollars to be consistent with the dollars used by AEO in its 2014 

Annual Energy Outlook.174 While the factors used to convert from 2009 dollars (or other) to 

2012 dollars are small, the agencies prefer to be overly diligent in this regard to ensure 

consistency across our benefit-cost analysis. The agencies have used the GDP Implicit Price 

Deflator for Gross Domestic Product as the converter, with the actual factors used as shown in 

Table 2-102.

175

Table 2-102 Implicit Price Deflators and Conversion Factors for Conversion to 2012$

CALENDAR YEAR 2005 2006 2007 2008 2009 2010 2011 2012 2013

Price index for GDP 91.991 94.818 97.335 99.236 100 101.211 103.199 105.002 106.588

Factor applied for 2012$ 1.141 1.107 1.079 1.058 1.050 1.037 1.017 1.000 0.985

The sections above describe the technologies expected to be used to enable compliance 

with the proposed standards and the adoption rates we estimate to be possible. Here we present 

the cost of each technology, the markups used for each, the learning effect applied, etc. The 

tables here present the direct manufacturing cost (DMC) we have estimated for each technology, 

the indirect costs (IC) associated with that technology, and the resultant total cost (TC) of each 

(where TC=DMC+IC). Each table also presents, where appropriate, the expected adoption rate 

of each technology in both the reference case (i.e., alternative 1a or the “no new controls” case) 

and the policy case (the proposed standards). For most technologies, the reference case adoption 

rate will be shown as 0 percent (or blanks in the tables) since the Phase 2 technologies are 

expected to be in limited or no use in the regulatory timeframe. However, for some 

technologies—notably tire and aero technologies—there is expected to considerably adoption of 

Phase 2 technologies in the reference case. The final row(s) of the tables shown here include the 

adoption rates applied to the technology costs to arrive at a total cost of each technology as it is 

applied to the ultimate package (noted as TCp). In Chapter 2.13 of this draft RIA, we sum these 

costs (the TCp costs) into total cost applied to the packages presented later in Chapter 7 of this 

draft RIA. We also describe how we moved from the total cost applied to the packages 

developed for the regulatory classes (i.e., Class 8 Sleeper cab, LH vocational medium-speed, 
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etc.) to the MOVES sourcetypes (i.e., transit bus, refuse truck, combination long haul, etc.) in 

order to develop program costs. This final step—moving from regulatory classes to MOVES 

sourcetypes, was necessary because MOVES populations, sales, inventory calculations, etc., are 

based on sourcetypes, not regulatory classes, and to allow for a more granular look at payback as 

presented in Chapter 7.4 of this draft RIA.

Note that the text surrounding the tables presented here refer to low/medium/high 

complexity ICMs and to learning curves used. We discuss both the ICMs and the learning 

effects used in this analysis in Chapter 2.12.1.2 and 2.12.1.3 of this draft RIA, respectively. 

2.12.2 Costs of Engine Technologies

2.12.2.1 Aftertreatment improvements

We have estimated the cost of aftertreatment improvements based on the aftertreatment 

improvements technology discussed in the Phase 1 rules. That technology was estimated at $25 

(DMC, 2008$, in 2014) for each percentage improvement in fuel consumption, or $100 (DMC, 

2008$, in 2014) for the 4 percent improvement expected as a result of that program. In Phase 2, 

we are expecting only a 0.6 percent improvement in fuel consumption resulting from 

aftertreatment improvements. Therefore, the cost in Phase 2 including updates to 2012$ is $16 

(DMC, 2012$, in 2014). We consider this technology to be on the flat portion of the learning 

curve (curve 2) and have applied a low complexity ICM with short term markups through 2024. 

The resultant technology costs, adoption rates and total cost applied to the package are shown in 

Table 2-103 for vocational engines and in Table 2-104 for tractor engines.

Table 2-103 Costs of Aftertreatment Improvements – Level 2

Light/Medium/Heavy HDD Vocational Engines (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Aftertreatment improvements 

– level 2

DMC $14 $14 $13 $13 $13 $13 $12 $12 $12 $12

Aftertreatment improvements 

– level 2

IC $2 $2 $2 $2 $2 $2 $2 $2 $2 $2

Aftertreatment improvements 

– level 2

TC $17 $16 $16 $16 $15 $15 $15 $14 $14 $14

Aftertreatment improvements 

– level 2

Alt 

1a

Aftertreatment improvements 

– level 2

Alt 3 50% 50% 50% 90% 90% 90% 100%

Aftertreatment improvements 

– level 2

TCp $0 $0 $0 $8 $8 $8 $13 $13 $13 $14

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption
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Table 2-104 Costs of Aftertreatment Improvements – Level 2

HDD Tractor Engines (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Aftertreatment improvements 

– level 2

DMC $14 $14 $13 $13 $13 $13 $12 $12 $12 $12

Aftertreatment improvements 

– level 2

IC $2 $2 $2 $2 $2 $2 $2 $2 $2 $2

Aftertreatment improvements 

– level 2

TC $17 $16 $16 $16 $15 $15 $15 $14 $14 $14

Aftertreatment improvements 

– level 2

Alt 

1a

Aftertreatment improvements 

– level 2

Alt 3 45% 45% 45% 95% 95% 95% 100%

Aftertreatment improvements 

– level 2

TCp $0 $0 $0 $7 $7 $7 $14 $13 $13 $14

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

2.12.2.2 Cylinder head improvements

We have estimated the cost of cylinder head improvements based on the cylinder head 

improvements technology discussed in the Phase 1 rules. That technology was estimated at $9 

(DMC, 2008$, in 2014) for light HDD engines and at $5 (DMC, 2008$, in 2014) for medium and 

heavy HDD engines. In Phase 2, we are estimating equivalent costs for an additional level of 

cylinder head improvements. With updates to 2012$, we estimate the costs at $10 (DMC, 

2012$, in 2021) for light HDD engines and at $6 (DMC, 2012$, in 2021) for medium and heavy 

HDD engines. We consider this technology to be on the flat portion of the learning curve (curve 

13) and have applied a low complexity ICM with short term markups through 2027. The 

resultant technology costs, adoption rates and total cost applied to the package are shown in 

Table 2-105 through Table 2-107.

Table 2-105 Costs for Cylinder Head Improvements – Level 2

Light HDD Vocational Engines (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Cylinder head improvements 

– level 2

DMC $11 $11 $10 $10 $10 $9 $9 $9 $9 $9

Cylinder head improvements 

– level 2

IC $2 $2 $2 $2 $2 $2 $2 $2 $2 $2

Cylinder head improvements 

– level 2

TC $12 $12 $12 $11 $11 $11 $11 $10 $10 $10

Cylinder head improvements 

– level 2

Alt 

1a

Cylinder head improvements 

– level 2

Alt 3 50% 50% 50% 90% 90% 90% 100%

Cylinder head improvements 

– level 2

TCp $0 $0 $0 $6 $6 $5 $10 $9 $10 $10

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption
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Table 2-106 Costs for Cylinder Head Improvements – Level 2

Medium/Heavy HDD Vocational Engines (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Cylinder head improvements 

– level 2

DMC $6 $6 $6 $6 $6 $5 $5 $5 $5 $5

Cylinder head improvements 

– level 2

IC $1 $1 $1 $1 $1 $1 $1 $1 $1 $1

Cylinder head improvements 

– level 2

TC $7 $7 $7 $7 $7 $6 $6 $6 $6 $6

Cylinder head improvements 

– level 2

Alt 

1a

Cylinder head improvements 

– level 2

Alt 3 50% 50% 50% 90% 90% 90% 100%

Cylinder head improvements 

– level 2

TCp $0 $0 $0 $3 $3 $3 $6 $5 $5 $6

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

Table 2-107 Costs for Cylinder Head Improvements – Level 2

HDD Tractor Engines (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Cylinder head improvements 

– level 2

DMC $6 $6 $6 $6 $6 $5 $5 $5 $5 $5

Cylinder head improvements 

– level 2

IC $1 $1 $1 $1 $1 $1 $1 $1 $1 $1

Cylinder head improvements 

– level 2

TC $7 $7 $7 $7 $7 $6 $6 $6 $6 $6

Cylinder head improvements 

– level 2

Alt 

1a

Cylinder head improvements 

– level 2

Alt 3 45% 45% 45% 95% 95% 95% 100%

Cylinder head improvements 

– level 2

TCp $0 $0 $0 $3 $3 $3 $6 $6 $6 $6

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

2.12.2.3 Turbocharger efficiency improvements

We have estimated the cost of turbo efficiency improvements based on the turbo 

efficiency improvements technology discussed in the Phase 1 rules. That technology was 

estimated at $16 (DMC, 2008$, in 2014) for all HDD engines. In Phase 2, we are estimating 

equivalent costs for an additional level of turbo efficiency improvements. With updates to 

2012$, we estimate the costs at $17 (DMC, 2012$, in 2021) for all HDD engines. We consider 

this technology to be on the flat portion of the learning curve (curve 13) and have applied a low 

complexity ICM with short term markups through 2027. The resultant technology costs, 

adoption rates and total cost applied to the package are shown in Table 2-108 and Table 2-109

for vocational and tractor engines.
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Table 2-108 Costs for Turbocharger Efficiency Improvements – Level 2

Light/Medium/Heavy HDD Vocational Engines (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Turbo efficiency 

improvements – level 2

DMC $18 $18 $17 $17 $16 $16 $15 $15 $14 $14

Turbo efficiency 

improvements – level 2

IC $3 $3 $3 $3 $3 $3 $3 $3 $3 $3

Turbo efficiency 

improvements – level 2

TC $21 $20 $20 $19 $19 $18 $18 $17 $17 $17

Turbo efficiency 

improvements – level 2

Alt 

1a

Turbo efficiency 

improvements – level 2

Alt 3 50% 50% 50% 90% 90% 90% 100%

Turbo efficiency 

improvements – level 2

TCp $0 $0 $0 $10 $9 $9 $16 $16 $15 $17

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

Table 2-109 Costs for Turbocharger Efficiency Improvements – Level 2

HDD Tractor Engines (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Turbo efficiency 

improvements – level 2

DMC $18 $18 $17 $17 $16 $16 $15 $15 $14 $14

Turbo efficiency 

improvements – level 2

IC $3 $3 $3 $3 $3 $3 $3 $3 $3 $3

Turbo efficiency 

improvements – level 2

TC $21 $20 $20 $19 $19 $18 $18 $17 $17 $17

Turbo efficiency 

improvements – level 2

Alt 

1a

Turbo efficiency 

improvements – level 2

Alt 3 45% 45% 45% 95% 95% 95% 100%

Turbo efficiency 

improvements – level 2

TCp $0 $0 $0 $9 $8 $8 $17 $16 $16 $17

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

For HD diesel pickups and vans, we are estimating use of the Phase 1 level of turbo 

efficiency improvements, or $17 (DMC, 2012$, in 2014). We consider this technology to be on 

the flat portion of the learning curve (curve 2) and have applied a low complexity ICM with 

short term markups through 2022. The resultant technology costs are shown in Table 2-110.

Table 2-110 Costs for Turbocharger Efficiency Improvements – Level 1

HD Pickups & Vans (2012$)

TECHNOLOGY 2021 2022 2023 2024 2025 2026 2027

Turbo efficiency improvements – level 1 DMC $14 $14 $13 $13 $13 $13 $13

Turbo efficiency improvements – level 1 IC $3 $3 $2 $2 $2 $2 $2

Turbo efficiency improvements – level 1 TC $16 $16 $15 $15 $15 $15 $15

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost
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2.12.2.4 Turbo compounding

We have estimated the cost of turbo compounding based on the turbo compounding 

technology discussed in the Phase 1 rules. That technology was estimated at $813 (DMC, 

2008$, in 2014) for all HDD tractor engines. In Phase 2, we are estimating equivalent costs for 

an additional level of turbo compounding improvements. With updates to 2012$, we estimate 

the costs at $860 (DMC, 2012$, in 2021) for all HDD tractor engines. We consider this 

technology to be on the flat portion of the learning curve (curve 13) and have applied a low 

complexity ICM with short term markups through 2027. The resultant technology costs, 

adoption rates and total cost applied to the package are shown in Table 2-111.

Table 2-111 Costs for Turbocharger Compounding – Level 2

HDD Tractor Engines (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Turbo compounding –

level 2

DMC $942 $914 $886 $860 $834 $809 $785 $769 $754 $738

Turbo compounding –

level 2

IC $134 $133 $133 $133 $133 $133 $133 $133 $132 $132

Turbo compounding –

level 2

TC $1,076 $1,047 $1,020 $993 $967 $942 $917 $902 $886 $871

Turbo compounding –

level 2

Alt 

1a

Turbo compounding –

level 2

Alt 3 5% 5% 5% 10% 10% 10% 10%

Turbo compounding –

level 2

TCp $0 $0 $0 $50 $48 $47 $92 $90 $89 $87

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

2.12.2.5 Valve actuation

We have estimated the cost of valve actuation based on the dual cam phasing cost 

estimate used in the 2017-2025 light-duty rule. In that analysis, we estimated costs at $151

(DMC, 2010$, in 2015) for a large V8 engine. In this HD Phase 2 program, we are estimating 

equivalent costs for this technology. With updates to 2012$, we estimate the costs at $157 

(DMC, 2012$, in 2015) for all HDD engines. We consider this technology to be on the flat 

portion of the learning curve (curve 8) and have applied a medium complexity ICM with short 

term markups through 2018. The resultant technology costs, adoption rates and total cost applied 

to the package are shown in Table 2-112 for vocational engines and in Table 2-113 for tractor 

engines.
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Table 2-112 Costs for Valve Actuation

Light/Medium/Heavy HDD Vocational Engines (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Valve actuation DMC $146 $143 $141 $138 $135 $132 $130 $127 $126 $125

Valve actuation IC $60 $45 $45 $45 $45 $45 $45 $45 $45 $44

Valve actuation TC $207 $188 $186 $183 $180 $177 $174 $172 $170 $169

Valve actuation Alt 

1a

Valve actuation Alt 3 50% 50% 50% 90% 90% 90% 100%

Valve actuation All $0 $0 $0 $91 $90 $89 $157 $154 $153 $169

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

Table 2-113 Costs for Valve Actuation

HDD Tractor Engines (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Valve actuation DMC $146 $143 $141 $138 $135 $132 $130 $127 $126 $125

Valve actuation IC $60 $45 $45 $45 $45 $45 $45 $45 $45 $44

Valve actuation TC $207 $188 $186 $183 $180 $177 $174 $172 $170 $169

Valve actuation Alt 

1a

Valve actuation Alt 3 45% 45% 45% 95% 95% 95% 100%

Valve actuation All $0 $0 $0 $82 $81 $80 $166 $163 $162 $169

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

For HD pickups and vans, we have estimated the costs of dual cam phasing based on the 

DMC, IC and TC presented above in Table 2-112.

For discrete variable valve lift (DVVL), we have again used the 2017-2025 light-duty

FRM values updated to 2012$ to arrive at a cost of $259 (DMC, 2012$, in 2015). We consider 

this technology to be on the flat portion of the learning curve (curve 8) and have applied medium 

complexity markups with short term markups through 2024. The resultant costs are presented in 

Table 2-114.

Table 2-114 Costs for Discrete Variable Valve Lift (DVVL)

Gasoline HD Pickups and Vans (2012$)

ITEM 2021 2022 2023 2024 2025 2026 2027

Discrete variable valve lift 

(DVVL)

DMC $227 $223 $218 $214 $210 $207 $205

Discrete variable valve lift 

(DVVL)

IC $74 $74 $74 $74 $74 $73 $73

Discrete variable valve lift 

(DVVL)

TC $301 $297 $292 $288 $283 $281 $279

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost

2.12.2.6 EGR 

We have estimated the cost of EGR cooler improvements based on the EGR cooler 

improvements technology discussed in the Phase 1 rules. That technology was estimated at $3 
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(DMC, 2008$, in 2014) for all HDD engines. In Phase 2, we are estimating equivalent costs for 

an additional level of EGR cooler improvements. With updates to 2012$, we estimate the costs 

at $3 (DMC, 2012$, in 2021) for all HDD engines. We consider this technology to be on the flat 

portion of the learning curve (curve 13) and have applied a low complexity ICM with short term 

markups through 2027. The resultant technology costs, adoption rates and total cost applied to 

the package are shown in Table 2-115 for vocational engines and in Table 2-116 for tractor 

engines.

Table 2-115 Costs for EGR Cooler Improvements – Level 2

Light/Medium/Heavy HDD Vocational Engines (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

EGR cooler – level 2 DMC $4 $4 $3 $3 $3 $3 $3 $3 $3 $3

EGR cooler – level 2 IC $1 $1 $1 $1 $1 $1 $1 $1 $1 $1

EGR cooler – level 2 TC $4 $4 $4 $4 $4 $4 $4 $3 $3 $3

EGR cooler – level 2 Alt 1a

EGR cooler – level 2 Alt 3 50% 50% 50% 90% 90% 90% 100%

EGR cooler – level 2 TCp $0 $0 $0 $2 $2 $2 $3 $3 $3 $3

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

Table 2-116 Costs for EGR Cooler Improvements – Level 2

HDD Tractor Engines (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

EGR cooler – level 2 DMC $4 $4 $3 $3 $3 $3 $3 $3 $3 $3

EGR cooler – level 2 IC $1 $1 $1 $1 $1 $1 $1 $1 $1 $1

EGR cooler – level 2 TC $4 $4 $4 $4 $4 $4 $4 $3 $3 $3

EGR cooler – level 2 Alt 1a

EGR cooler – level 2 Alt 3 45% 45% 45% 95% 95% 95% 100%

EGR cooler – level 2 TCp $0 $0 $0 $2 $2 $2 $3 $3 $3 $3

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

For HD pickups and vans, we have estimated the costs of adding cooled EGR to a 

gasoline engine based on the values used in the 2017-2025 light-duty FRM. We have scaled 

upward the light-duty value by 25 percent and converted to 2012$ to arrive at a cost of $317 

(DMC, 2012$, in 2012). We consider this technology to be on the flat portion of the learning 

curve (curve 7) and have applied medium complexity markups with near term markups through 

2024. The resultant costs are presented in Table 2-117. 

Table 2-117 Costs for Cooled EGR

Gasoline HD Pickups and Vans (2012$)

ITEM 2021 2022 2023 2024 2025 2026 2027

Cooled EGR DMC $253 $248 $243 $239 $234 $231 $229

Cooled EGR IC $120 $120 $119 $119 $89 $89 $89

Cooled EGR TC $373 $368 $363 $358 $323 $321 $318

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost
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2.12.2.7 Water pump improvements

We have estimated the cost of water pump improvements based on the water pump 

improvements technology discussed in the Phase 1 rules. That technology was estimated at $78 

(DMC, 2008$, in 2014) for all HDD engines. In Phase 2, we are estimating equivalent costs for 

an additional level of water pump improvements. With updates to 2012$, we estimate the costs 

at $83 (DMC, 2012$, in 2021) for all HDD engines. We consider this technology to be on the 

flat portion of the learning curve (curve 13) and have applied a low complexity ICM with short 

term markups through 2027. The resultant technology costs, adoption rates and total cost applied 

to the package are shown in Table 2-118 for vocational engines and in Table 2-119 for tractor 

engines.

Table 2-118 Costs for Water Pump Improvements – Level 2

Light/Medium/Heavy HDD Vocational Engines (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Water pump – level 2 DMC $91 $88 $85 $83 $80 $78 $75 $74 $72 $71

Water pump – level 2 IC $13 $13 $13 $13 $13 $13 $13 $13 $13 $13

Water pump – level 2 TC $103 $101 $98 $95 $93 $91 $88 $87 $85 $84

Water pump – level 2 Alt 1a

Water pump – level 2 Alt 3 60% 60% 60% 90% 90% 90% 100%

Water pump – level 2 TCp $0 $0 $0 $57 $56 $54 $79 $78 $77 $84

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

Table 2-119 Costs for Water Pump Improvements – Level 2

HDD Tractor Engines (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Water pump – level 2 DMC $91 $88 $85 $83 $80 $78 $75 $74 $72 $71

Water pump – level 2 IC $13 $13 $13 $13 $13 $13 $13 $13 $13 $13

Water pump – level 2 TC $103 $101 $98 $95 $93 $91 $88 $87 $85 $84

Water pump – level 2 Alt 1a

Water pump – level 2 Alt 3 45% 45% 45% 95% 95% 95% 100%

Water pump – level 2 TCp $0 $0 $0 $43 $42 $41 $84 $82 $81 $84

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

2.12.2.8 Oil pump improvements

We have estimated the cost of oil pump improvements based on the oil pump 

improvements technology discussed in the Phase 1 rules. That technology was estimated at just 

under $4 (DMC, 2008$, in 2014) for all HDD engines. In Phase 2, we are estimating equivalent 

costs for an additional level of oil pump improvements. With updates to 2012$, we estimate the

costs at just over $4 (DMC, 2012$, in 2021) for all HDD engines. We consider this technology

to be on the flat portion of the learning curve (curve 13) and have applied a low complexity ICM 

with short term markups through 2027. The resultant technology costs, adoption rates and total 
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cost applied to the package are shown in Table 2-120 for vocational engines and in Table 2-121

for tractor engines.

Table 2-120 Costs for Oil Pump Improvements – Level 2

Light/Medium/Heavy HDD Vocational Engines (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Oil pump – level 2 DMC $5 $4 $4 $4 $4 $4 $4 $4 $4 $4

Oil pump – level 2 IC $1 $1 $1 $1 $1 $1 $1 $1 $1 $1

Oil pump – level 2 TC $5 $5 $5 $5 $5 $5 $4 $4 $4 $4

Oil pump – level 2 Alt 1a

Oil pump – level 2 Alt 3 60% 60% 60% 90% 90% 90% 100%

Oil pump – level 2 TCp $0 $0 $0 $3 $3 $3 $4 $4 $4 $4

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

Table 2-121 Costs for Oil Pump Improvements – Level 2

HDD Tractor Engines (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Oil pump – level 2 DMC $5 $4 $4 $4 $4 $4 $4 $4 $4 $4

Oil pump – level 2 IC $1 $1 $1 $1 $1 $1 $1 $1 $1 $1

Oil pump – level 2 TC $5 $5 $5 $5 $5 $5 $4 $4 $4 $4

Oil pump – level 2 Alt 1a

Oil pump – level 2 Alt 3 45% 45% 45% 95% 95% 95% 100%

Oil pump – level 2 TCp $0 $0 $0 $2 $2 $2 $4 $4 $4 $4

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

2.12.2.9 Fuel pump improvements

We have estimated the cost of fuel pump improvements based on the fuel pump 

improvements technology discussed in the Phase 1 rules. That technology was estimated at just 

under $4 (DMC, 2008$, in 2014) for all HDD engines. In Phase 2, we are estimating equivalent 

costs for an additional level of fuel pump improvements. With updates to 2012$, we estimate the 

costs at just over $4 (DMC, 2012$, in 2021) for all HDD engines. We consider this technology

to be on the flat portion of the learning curve (curve 13) and have applied a low complexity ICM 

with short term markups through 2027. The resultant technology costs, adoption rates and total 

cost applied to the package are shown in Table 2-122 for vocational engines and in Table 2-123

for tractor engines.
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Table 2-122 Costs for Fuel Pump Improvements – Level 2

Light/Medium/Heavy HDD Vocational Engines (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Fuel pump – level 2 DMC $5 $4 $4 $4 $4 $4 $4 $4 $4 $4

Fuel pump – level 2 IC $1 $1 $1 $1 $1 $1 $1 $1 $1 $1

Fuel pump – level 2 TC $5 $5 $5 $5 $5 $5 $4 $4 $4 $4

Fuel pump – level 2 Alt 1a

Fuel pump – level 2 Alt 3 60% 60% 60% 90% 90% 90% 100%

Fuel pump – level 2 TCp $0 $0 $0 $3 $3 $3 $4 $4 $4 $4

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

Table 2-123 Costs for Fuel Pump Improvements – Level 2

HDD Tractor Engines (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Fuel pump – level 2 DMC $5 $4 $4 $4 $4 $4 $4 $4 $4 $4

Fuel pump – level 2 IC $1 $1 $1 $1 $1 $1 $1 $1 $1 $1

Fuel pump – level 2 TC $5 $5 $5 $5 $5 $5 $4 $4 $4 $4

Fuel pump – level 2 Alt 1a

Fuel pump – level 2 Alt 3 45% 45% 45% 95% 95% 95% 100%

Fuel pump – level 2 TCp $0 $0 $0 $2 $2 $2 $4 $4 $4 $4

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

2.12.2.10 Fuel rail improvements

We have estimated the cost of fuel rail improvements based on the fuel rail improvements 

technology discussed in the Phase 1 rules. That technology was estimated at $10 (DMC, 2008$, 

in 2014) for LHDD engines and just under $9 (DMC, 2008$, in 2014) for MHDD and HHDD 

engines. In Phase 2, we are estimating equivalent costs for an additional level of fuel rail 

improvements. With updates to 2012$, we estimate the costs at $11 (DMC, 2012$, in 2021) for 

LHDD and at just over $9 (DMC, 2012$, in 2021) for MHDD and HHDD engines. We consider 

this technology to be on the flat portion of the learning curve (curve 13) and have applied a low 

complexity ICM with short term markups through 2027. The resultant technology costs, 

adoption rates and total cost applied to the package are shown in Table 2-124 through Table 

2-126.
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Table 2-124 Costs for Fuel Rail Improvements – Level 2

Light HDD Vocational Engines (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Fuel rail – level 2 DMC $12 $11 $11 $11 $10 $10 $10 $10 $9 $9

Fuel rail – level 2 IC $2 $2 $2 $2 $2 $2 $2 $2 $2 $2

Fuel rail – level 2 TC $13 $13 $13 $12 $12 $12 $11 $11 $11 $11

Fuel rail – level 2 Alt 1a

Fuel rail – level 2 Alt 3 60% 60% 60% 90% 90% 90% 100%

Fuel rail – level 2 TCp $0 $0 $0 $7 $7 $7 $10 $10 $10 $11

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

Table 2-125 Costs for Fuel Rail Improvements – Level 2

Medium/Heavy HDD Vocational Engines (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Fuel rail – level 2 DMC $10 $10 $9 $9 $9 $9 $8 $8 $8 $8

Fuel rail – level 2 IC $1 $1 $1 $1 $1 $1 $1 $1 $1 $1

Fuel rail – level 2 TC $11 $11 $11 $11 $10 $10 $10 $10 $9 $9

Fuel rail – level 2 Alt 1a

Fuel rail – level 2 Alt 3 60% 60% 60% 90% 90% 90% 100%

Fuel rail – level 2 TCp $0 $0 $0 $6 $6 $6 $9 $9 $8 $9

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

Table 2-126 Costs for Fuel Rail Improvements – Level 2

HDD Tractor Engines (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Fuel rail – level 2 DMC $10 $10 $9 $9 $9 $9 $8 $8 $8 $8

Fuel rail – level 2 IC $1 $1 $1 $1 $1 $1 $1 $1 $1 $1

Fuel rail – level 2 TC $11 $11 $11 $11 $10 $10 $10 $10 $9 $9

Fuel rail – level 2 Alt 1a

Fuel rail – level 2 Alt 3 45% 45% 45% 95% 95% 95% 100%

Fuel rail – level 2 TCp $0 $0 $0 $5 $5 $4 $9 $9 $9 $9

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

2.12.2.11 Fuel injector improvements 

We have estimated the cost of fuel injector improvements based on the fuel injector 

improvements technology discussed in the Phase 1 rules. That technology was estimated at $13 

(DMC, 2008$, in 2014) for LHDD engines and $9 (DMC, 2008$, in 2014) for MHDD and 

HHDD engines. In Phase 2, we are estimating equivalent costs for an additional level of fuel 

injector improvements. With updates to 2012$, we estimate the costs at $13 (DMC, 2012$, in 

2021) for LHDD and at $10 (DMC, 2012$, in 2021) for MHDD and HHDD engines. We 

consider this technology to be on the flat portion of the learning curve (curve 13) and have 

applied a low complexity ICM with short term markups through 2027. The resultant technology
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costs, adoption rates and total cost applied to the package are shown in Table 2-127 through

Table 2-129.

Table 2-127 Costs for Fuel Injector Improvements – Level 2

Light HDD Vocational Engines (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Fuel injectors – level 2 DMC $14 $14 $14 $13 $13 $12 $12 $12 $12 $11

Fuel injectors – level 2 IC $2 $2 $2 $2 $2 $2 $2 $2 $2 $2

Fuel injectors – level 2 TC $17 $16 $16 $15 $15 $14 $14 $14 $14 $13

Fuel injectors – level 2 Alt 1a

Fuel injectors – level 2 Alt 3 50% 50% 50% 90% 90% 90% 100%

Fuel injectors – level 2 TCp $0 $0 $0 $8 $7 $7 $13 $12 $12 $13

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative package; alt=alternative; empty cells for adoption rates denote 0% adoption

Table 2-128 Costs for Fuel Injector Improvements – Level 2

Medium/Heavy HDD Vocational Engines (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Fuel injectors – level 2 DMC $11 $11 $10 $10 $10 $9 $9 $9 $9 $9

Fuel injectors – level 2 IC $2 $2 $2 $2 $2 $2 $2 $2 $2 $2

Fuel injectors – level 2 TC $12 $12 $12 $11 $11 $11 $11 $10 $10 $10

Fuel injectors – level 2 Alt 1a

Fuel injectors – level 2 Alt 3 50% 50% 50% 90% 90% 90% 100%

Fuel injectors – level 2 TCp $0 $0 $0 $6 $6 $5 $10 $9 $9 $10

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

Table 2-129 Costs for Fuel Injector Improvements – Level 2

HDD Tractor Engines (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Fuel injectors – level 2 DMC $11 $11 $10 $10 $10 $9 $9 $9 $9 $9

Fuel injectors – level 2 IC $2 $2 $2 $2 $2 $2 $2 $2 $2 $2

Fuel injectors – level 2 TC $12 $12 $12 $11 $11 $11 $11 $10 $10 $10

Fuel injectors – level 2 Alt 1a

Fuel injectors – level 2 Alt 3 45% 45% 45% 95% 95% 95% 100%

Fuel injectors – level 2 TCp $0 $0 $0 $5 $5 $5 $10 $10 $10 $10

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

2.12.2.12 Piston improvements

We have estimated the cost of piston improvements based on the piston improvements 

technology discussed in the Phase 1 rules. That technology was estimated at just over $2 (DMC, 

2008$, in 2014) for all HDD engines. In Phase 2, we are estimating equivalent costs for an 

additional level of fuel pump improvements. With updates to 2012$, we estimate the costs at 

over $2 (DMC, 2012$, in 2021) for all HDD engines. We consider this technology to be on the 

flat portion of the learning curve (curve 13) and have applied a low complexity ICM with short 
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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term markups through 2027. The resultant technology costs, adoption rates and total cost applied 

to the package are shown in Table 2-130 for vocational engines and in Table 2-131 for tractor 

engines.

Table 2-130 Costs for Fuel Pump Improvements – Level 2

Light/Medium/Heavy HDD Vocational Engines (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Piston improvements – level 

2

DMC $3 $3 $3 $2 $2 $2 $2 $2 $2 $2

Piston improvements – level 

2

IC $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

Piston improvements – level 

2

TC $3 $3 $3 $3 $3 $3 $3 $3 $3 $3

Piston improvements – level 

2

Alt 1a

Piston improvements – level 

2

Alt 3 50% 50% 50% 90% 90% 90% 100%

Piston improvements – level 

2

TCp $0 $0 $0 $1 $1 $1 $2 $2 $2 $3

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

Table 2-131 Costs for Fuel Pump Improvements – Level 2

HDD Tractor Engines (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Piston improvements – level 

2

DMC $3 $3 $3 $2 $2 $2 $2 $2 $2 $2

Piston improvements – level 

2

IC $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

Piston improvements – level 

2

TC $3 $3 $3 $3 $3 $3 $3 $3 $3 $3

Piston improvements – level

2

Alt 1a

Piston improvements – level 

2

Alt 3 45% 45% 45% 95% 95% 95% 100%

Piston improvements – level 

2

TCp $0 $0 $0 $1 $1 $1 $3 $2 $2 $3

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

2.12.2.13 Valvetrain friction reduction

We have estimated the cost of valvetrain friction reduction based on the valvetrain 

friction reduction technology discussed in the Phase 1 rules. That technology was estimated at 

$94 (DMC, 2008$, in 2014) for LHDD engines and $70 (DMC, 2008$, in 2014) for MHDD and 

HHDD engines. In Phase 2, we are estimating equivalent costs for an additional level of fuel 

injector improvements. With updates to 2012$, we estimate the costs at $99 (DMC, 2012$, in 

2021) for LHDD and at $74 (DMC, 2012$, in 2021) for MHDD and HHDD engines. We 
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consider this technology to be on the flat portion of the learning curve (curve 13) and have 

applied a low complexity ICM with short term markups through 2027. The resultant technology

costs, adoption rates and total cost applied to the package are shown in Table 2-132 and Table 

2-133 for vocational engines and in Table 2-134 for tractor engines.

Table 2-132 Costs for Valvetrain Friction Improvements – Level 2

Light HDD Vocational Engines (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Valvetrain friction reduction 

– level 2

DMC $109 $105 $102 $99 $96 $93 $91 $89 $87 $85

Valvetrain friction reduction 

– level 2

IC $15 $15 $15 $15 $15 $15 $15 $15 $15 $15

Valvetrain friction reduction 

– level 2

TC $124 $121 $118 $115 $112 $109 $106 $104 $102 $100

Valvetrain friction reduction 

– level 2

Alt 

1a

Valvetrain friction reduction 

– level 2

Alt 3 60% 60% 60% 90% 90% 90% 100%

Valvetrain friction reduction 

– level 2

TCp $0 $0 $0 $69 $67 $65 $95 $94 $92 $100

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

Table 2-133 Costs for Valvetrain Friction Improvements – Level 2

Medium/Heavy HDD Vocational Engines (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Valvetrain friction reduction 

– level 2

DMC $82 $79 $77 $74 $72 $70 $68 $67 $65 $64

Valvetrain friction reduction 

– level 2

IC $12 $12 $12 $12 $12 $11 $11 $11 $11 $11

Valvetrain friction reduction 

– level 2

TC $93 $91 $88 $86 $84 $81 $79 $78 $77 $75

Valvetrain friction reduction 

– level 2

Alt 

1a

Valvetrain friction reduction 

– level 2

Alt 3 60% 60% 60% 90% 90% 90% 100%

Valvetrain friction reduction 

– level 2

TCp $0 $0 $0 $52 $50 $49 $71 $70 $69 $75

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption
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2-220

Table 2-134 Costs for Valvetrain Friction Improvements – Level 2

HDD Tractor Engines (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Valvetrain friction reduction 

– level 2

DMC $82 $79 $77 $74 $72 $70 $68 $67 $65 $64

Valvetrain friction reduction 

– level 2

IC $12 $12 $12 $12 $12 $11 $11 $11 $11 $11

Valvetrain friction reduction 

– level 2

TC $93 $91 $88 $86 $84 $81 $79 $78 $77 $75

Valvetrain friction reduction 

– level 2

Alt 

1a

Valvetrain friction reduction 

– level 2

Alt 3 45% 45% 45% 95% 95% 95% 100%

Valvetrain friction reduction 

– level 2

TCp $0 $0 $0 $39 $38 $37 $75 $74 $73 $75

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

2.12.2.14 “Right-sized” diesel engine

We have estimated the cost of a slightly smaller diesel engine at a $500 savings (DMC, 

2013$, in any year) for all HDD tractor engines. We believe this represents an opportunity for 

lower costs because smaller diesel engines contain less materials and are, generally, less costly to 

produce than a larger diesel engine. In 2012$, we estimate the costs at $493 (DMC, 2012$, in 

any year) for all HDD tractor engines. As this cost is considered applicable in any year, we have 

applied not learning effects (curve 1). We have applied a low complexity ICM with short term 

markups through 2022. The resultant technology costs, adoption rates and total cost applied to 

the package are shown in Table 2-135 for tractor engines. For HD pickups and vans, we 

estimated the right-sized diesel engine cost as cost neutral to any reference case diesel engine 

and limited the technology to diesel vans. We have not included any costs associated with lost 

utility of the smaller diesel engine. We believe that the smaller engine would be attractive to 

some buyers, but not all, and that those buyers would not be concerned by any possible lost 

utility. For that reason, we have used a limited application rate for this technology since, as 

noted, not all buyers would be interested in this option due to the potential for lost utility. Note 

that, for HD pickups and vans, we have considered this technology to be cost neutral.
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Table 2-135 Costs for “Right-sized” HDD Tractor Engines (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Right-sized 

diesel engine

DMC -$493 -$493 -$493 -$493 -$493 -$493 -$493 -$493 -$493 -$493

Right-sized 

diesel engine

IC $88 $88 $88 $88 $88 $69 $69 $69 $69 $69

Right-sized 

diesel engine

TC -$405 -$405 -$405 -$405 -$405 -$424 -$424 -$424 -$424 -$424

Right-sized 

diesel engine

Alt 1a

Right-sized 

diesel engine

Alt 3 10% 10% 10% 20% 20% 20% 30%

Right-sized 

diesel engine

TCp $0 $0 $0 -$40 -$40 -$42 -$85 -$85 -$85 -$127

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

2.12.2.15 Waste heat recovery

We have estimated the cost of waste heat recovery based on the estimate from Tetra Tech 

showing it at $12,000 (retail, 2013$). Using that $12,000 estimate and dividing by a 1.36 RPE 

(see Chapter 2.12.1.2 of this draft RIA) and converting to 2012$, we arrive at our estimated 

DMC of $8,692 (DMC, 2012$, in 2018). We consider this technology to be on the flat portion of 

the learning curve (curve 12) because although waste heat recovery is a new technology and in 

the 2015 to 2017 timeframe remains, perhaps, on the steeper portion of the learning curve, 

applying such rapid learning effects to the cost estimate we have would result in costs too low in 

the MY2024 to 2027 timeframe. We have applied a medium complexity ICM with short term 

markups through 2025. The resultant technology costs, adoption rates and total cost applied to 

the package are shown in Table 2-136 for tractor engines. 
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Table 2-136 Costs for Waste Heat Recovery

HDD Tractor Engines (2012$)

ITEM 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Waste 

heat 

recovery

DMC $8,692 $8,431 $8,179 $7,933 $7,775 $7,619 $7,467 $7,317 $7,171 $7,028

Waste 

heat 

recovery

IC $2,628 $2,615 $2,602 $2,589 $2,581 $2,574 $2,566 $2,558 $1,908 $1,903

Waste 

heat 

recovery

TC $11,320 $11,046 $10,780 $10,523 $10,356 $10,193 $10,032 $9,876 $9,079 $8,931

Waste 

heat 

recovery

Alt 

1a

Waste 

heat 

recovery

Alt 3 1% 1% 1% 5% 5% 5% 15%

Waste 

heat 

recovery

TCp $0 $0 $0 $105 $104 $102 $502 $494 $454 $1,340

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

2.12.2.16 Model-based control

We have estimated the cost of model-based controls at $100 (DMC, 2013$). Using that 

estimate and converting to 2012$, we arrive at our estimated DMC of $99 (DMC, 2012$, in 

2021). We consider this technology to be on the flat portion of the learning curve (curve 13) and 

have applied a low complexity ICM with short term markups through 2022. The resultant 

technology costs, adoption rates and total cost applied to the package are shown in Table 2-137

for vocational engines.

Table 2-137 Costs for Model Based Controls

Light/Medium/Heavy HDD Vocational Engines (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Model-based control DMC $108 $105 $102 $99 $96 $93 $90 $88 $86 $85

Model-based control IC $15 $15 $15 $15 $15 $12 $12 $12 $12 $12

Model-based control TC $123 $120 $117 $114 $111 $105 $102 $100 $99 $97

Model-based control Alt 1a

Model-based control Alt 3 25% 25% 25% 30% 30% 30% 40%

Model-based control TCp $0 $0 $0 $28 $28 $26 $31 $30 $30 $39

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

2.12.2.17 Engine friction reduction and accommodating low friction lubes

We have based the costs for accommodating low friction lubes (LUB) on the costs used 

in the light-duty 2017-2025 FRM but have scaled upward that cost by 50 percent to account for 

the larger HD engines. Using that cost ($3 DMC, 2006$, in any year) and converting to 2012$ 
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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results in a cost of $5 (DMC, 2012$, in any year). We consider this technology to be beyond 

learning (curve 1) and have applied low complexity markups with near term markups through 

2018. The resultant costs for HD pickups and vans are shown in are shown in Table 2-138.

Table 2-138 Costs for Accommodating Low Friction Lubes

Gasoline & Diesel HD Pickups and Vans (2012$)

ITEM 2021 2022 2023 2024 2025 2026 2027

Engine friction reduction - level 

1

DMC $5 $5 $5 $5 $5 $5 $5

Engine friction reduction - level 

1

IC $1 $1 $1 $1 $1 $1 $1

Engine friction reduction - level 

1

TC $6 $6 $6 $6 $6 $6 $6

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost

We have based the costs for engine friction reduction level 1 (EFR1) on the costs used in 

the light-duty 2017-2025 FRM. That cost is based on an original estimate of $11/cylinder 

(DMC, 2006$, in any year). Using that cost for an 8 cylinder engine and converting to 2012$ 

results in a cost of $97 (DMC, 2012$, in any year). We consider this technology to be beyond 

learning (curve 1) and have applied low complexity markups with near term markups through 

2018. The resultant costs for HD pickups and vans are shown in are shown in Table 2-139.

Table 2-139 Costs for Engine Friction Reduction – Level 1

Gasoline & Diesel HD Pickups and Vans (2012$)

ITEM 2021 2022 2023 2024 2025 2026 2027

Engine friction reduction - level 

1

DMC $97 $97 $97 $97 $97 $97 $97

Engine friction reduction - level 

1

IC $19 $19 $19 $19 $19 $19 $19

Engine friction reduction - level 

1

TC $116 $116 $116 $116 $116 $116 $116

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost

For engine friction reduction level 2 (EFR2, which includes costs for accommodating low 

friction lubes) we have used the same approach as used in the light-duty 2017-2025 rule in that 

we have doubled the DMC associated with LUB and EFR1. As with those technologies, we 

consider EFR2 to be beyond learning (curve 1) and have applied low complexity markups but 

have applied near term markups through 2024. The resultant costs for gasoline HD pickups and 

vans are shown in Table 2-140.
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-140 Costs for Engine Friction Reduction – Level 2

Gasoline HD Pickups and Vans (2012$)

ITEM 2021 2022 2023 2024 2025 2026 2027

Engine friction reduction - level 

2

DMC $205 $205 $205 $205 $205 $205 $205

Engine friction reduction - level 

2

IC $50 $50 $50 $50 $39 $39 $39

Engine friction reduction - level 

2

TC $254 $254 $254 $254 $244 $244 $244

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost

For diesel HD pickups and vans, we have used the above costs for EFR level 2 and added 

to that costs associated with improvements to other parasitic loads on the engine. For that latter 

portion of the cost, we have used the light HDD engine DMCs for improved water pump level 1, 

improved oil pump level 1, improved fuel pump level 1, improved fuel injectors level 1 and 

valvetrain friction reduction level 1, which together result in a cost of $193 (DMC, 2012$, in and 

year). We consider this combined set of technologies to be beyond the effects of learning (curve 

1) and have applied low complexity markups with near term markups through 2022. The 

resultant costs for diesel HD pickups and vans are shown in Table 2-141.

Table 2-141 Costs for Engine Friction Reduction & Improvements to Other Parasitics

Diesel HD Pickups and Vans (2012$)

ITEM 2021 2022 2023 2024 2025 2026 2027

Engine friction reduction -

diesel

DMC $397 $397 $397 $397 $397 $397 $397

Engine friction reduction -

diesel

IC $96 $96 $87 $87 $77 $77 $77

Engine friction reduction -

diesel

TC $494 $494 $484 $484 $474 $474 $474

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost

2.12.2.18 Cylinder deactivation

For cylinder deactivation on HD pickups and vans, we have based the costs on values 

presented in the light-duty 2017-2025 FRM with updates to 2012$ to arrive at a cost of $169 

(DMC, 2012$, in 2015). We consider this technology to be on the flat portion of the learning 

curve (curve 8) and have applied medium complexity markups with near term markups through 

2018. The resultant costs are presented in Table 2-142.

Table 2-142 Costs for Cylinder Deactivation

Gasoline HD Pickups and Vans (2012$)

ITEM 2021 2022 2023 2024 2025 2026 2027

Cylinder 

deactivation

DMC $148 $145 $142 $139 $137 $135 $134

Cylinder 

deactivation

IC $48 $48 $48 $48 $48 $48 $48

Cylinder 

deactivation

TC $196 $193 $190 $187 $185 $183 $182

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost
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2.12.2.19 Stoichiometric gasoline direct injection (SGDI)

For gasoline direct injection on HD pickups and vans, we have based the costs on values 

presented in the light-duty 2017-2025 FRM with updates to 2012$ to arrive at a cost of $417 

(DMC, 2012$, in 2012). We consider this technology to be on the flat portion of the learning 

curve (curve 7) and have applied medium complexity markups with near term markups through 

2018. The resultant costs are presented in Table 2-143.

Table 2-143 Costs for Direct Injection

Gasoline HD Pickups and Vans (2012$)

ITEM 2021 2022 2023 2024 2025 2026 2027

Gasoline direct 

injection

DMC $333 $327 $320 $314 $307 $304 $301

Gasoline direct 

injection

IC $118 $118 $118 $117 $117 $117 $117

Gasoline direct 

injection

TC $451 $445 $438 $431 $425 $422 $418

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost.

2.12.2.20 Turbocharging & downsizing

For turbocharging and downsizing (TDS) on HD pickups and vans, we have based the 

costs on values presented in the light-duty 2017-2025 FRM with updates to 2012$. For the twin 

turbo configuration expected on a V6 engine (downsized from a V8), we estimate the cost at 

$735 (DMC, 2012$, in 2012). We consider this technology to be on the flat portion of the 

learning curve (curve 7) and have applied medium complexity markups with near term markups 

through 2018. For downsizing from an overhead valve (OHV) V8 to an overhead cam (OHC) 

V6 valvetrain, we have estimated the cost at $340 (DMC, 2012$, in 2017). We consider this 

technology to be on the flat portion of the learning curve (curve 6) and have applied medium

complexity markups with near term markups through 2018. For downsizing from an OHC V8 to 

an OHC V6, we have estimated the cost at -$295 (DMC, 2012$, in 2012). We consider this 

technology to be on the flat portion of the learning curve to arrive at a cost of $417 (DMC, 

2012$, in 2012). We consider this technology to be on the flat portion of the learning curve 

(curve 7) and have applied medium complexity markups with near term markups through 2024. 

The resultant costs for the turbocharging system are shown in Table 2-144, for downsizing from 

an OHV V8 to an OHC V6 in Table 2-145, and downsizing from an OHC V8 to an OHC V6 in 

Table 2-146.

Table 2-144 Costs for Adding Twin Turbos

Gasoline HD Pickups and Vans (2012$)

ITEM 2021 2022 2023 2024 2025 2026 2027

Adding 

twin turbos

DMC $588 $576 $565 $553 $542 $537 $531

Adding 

twin turbos

IC $208 $208 $208 $207 $207 $207 $207

Adding 

twin turbos

TC $796 $784 $772 $761 $749 $744 $738

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost
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Table 2-145 Costs for Downsizing from an OHV V8 to an OHC V6

Gasoline HD Pickups and Vans (2012$)

ITEM 2021 2022 2023 2024 2025 2026 2027

Downsizing from OHV 

V8 to OHC V6

DMC $301 $292 $286 $280 $275 $269 $264

Downsizing from OHV 

V8 to OHC V6

IC $97 $97 $97 $97 $96 $96 $96

Downsizing from OHV 

V8 to OHC V6

TC $398 $389 $383 $377 $371 $365 $360

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost

Table 2-146 Costs for Downsizing from an OHC V8 to an OHC V6

Gasoline HD Pickups and Vans (2012$)

ITEM 2021 2022 2023 2024 2025 2026 2027

Downsizing from OHC 

V8 to OHC V6

DMC -$236 -$232 -$227 -$223 -$218 -$216 -$214

Downsizing from OHC 

V8 to OHC V6

IC $112 $112 $111 $111 $83 $83 $83

Downsizing from OHC 

V8 to OHC V6

TC -$125 -$120 -$116 -$111 -$135 -$133 -$131

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost

2.12.3 Transmissions

2.12.3.1 Adding additional gears (vocational)

We have estimated the cost of adding 2 additional gears for vocational vehicles 

(light/medium HD, heavy HD urban/multipurpose) based on the light-duty cost for an 8 speed 

automatic transmission relative to a 6 speed automatic of $78 (DMC, 2010$, in 2012).R We have 

scaled that value by typical torque values of 2000 foot-pounds for vocational and 332 for a lightduty truck. With updates to 2012$, this DMC for vocational vehicles becomes $486 (DMC, 

2012$, in 2012). We consider this technology to be on the flat portion of the learning curve 

(curve 7) and have applied a medium complexity ICM with short term markups through 2018. 

The resultant technology costs, adoption rates and total cost applied to the package are shown in 

Table 2-147 and Table 2-148 for vocational vehicles.

 

R This cost was updated by FEV in early 2013. We are using the updated cost here, not the value used in the lightduty 2017-2025 final rule.
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-147 Costs for Adding 2 Gears to an Automatic Transmission

Vocational Light/Medium/Heavy HD Urban/Multipurpose Vehicles (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Adding additional gears DMC $413 $405 $397 $389 $381 $374 $366 $359 $355 $352

Adding additional gears IC $143 $107 $107 $106 $106 $106 $105 $105 $105 $105

Adding additional gears TC $557 $512 $504 $495 $487 $479 $472 $464 $460 $457

Adding additional gears Alt 1a

Adding additional gears Alt 3 5% 5% 5% 5% 5% 5% 5%

Adding additional gears TCp $0 $0 $0 $25 $24 $24 $24 $23 $23 $23

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

Table 2-148 Costs for Adding 2 Gears to an Automatic Transmission

Vocational Light/Medium HD Regional Vehicles (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Adding additional gears DMC $413 $405 $397 $389 $381 $374 $366 $359 $355 $352

Adding additional gears IC $143 $107 $107 $106 $106 $106 $105 $105 $105 $105

Adding additional gears TC $557 $512 $504 $495 $487 $479 $472 $464 $460 $457

Adding additional gears Alt 1a

Adding additional gears Alt 3 5% 5% 5% 5% 5% 5% 10%

Adding additional gears TCp $0 $0 $0 $25 $24 $24 $24 $23 $23 $46

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

2.12.3.2 Automated manual transmissions (AMT)

We have estimated the cost of an AMT transmission, relative to a manual transmission, 

based on an estimate by Tetra Tech of $5,100 (retail, 2013$). Using that estimate, we divided by

an RPE of 1.36 and converted to 2012$ to arrive at an estimated cost of $3694 (DMC, 2012$, in 

2018). We consider this technology to be on the flat portion of the learning curve (curve 12) and 

have applied a medium complexity ICM with short term markups through 2022. The resultant 

technology costs, adoption rates and total cost applied to the package are shown in Table 2-149

for vocational vehicles and in Table 2-150 for tractors.
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Table 2-149 Costs for an AMT Transmission

Vocational Heavy HD Regional Vehicles (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Manual to AMT DMC $3,694 $3,583 $3,476 $3,372 $3,304 $3,238 $3,173 $3,110 $3,048 $2,987

Manual to AMT IC $1,117 $1,111 $1,106 $1,101 $1,097 $818 $815 $813 $811 $809

Manual to AMT TC $4,811 $4,695 $4,582 $4,472 $4,401 $4,056 $3,989 $3,923 $3,859 $3,795

Manual to AMT Alt 

1a

Manual to AMT Alt 3 22% 22% 22% 33% 33% 33% 25%

Manual to AMT TCp $0 $0 $0 $984 $968 $892 $1,316 $1,295 $1,273 $949

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

Table 2-150 Costs for an AMT Transmission

Tractors (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Manual to AMT DMC $3,694 $3,583 $3,476 $3,372 $3,304 $3,238 $3,173 $3,110 $3,048 $2,987

Manual to AMT IC $1,117 $1,111 $1,106 $1,101 $1,097 $818 $815 $813 $811 $809

Manual to AMT TC $4,811 $4,695 $4,582 $4,472 $4,401 $4,056 $3,989 $3,923 $3,859 $3,795

Manual to AMT Alt 

1a

Manual to AMT Alt 3 40% 40% 40% 50% 50% 50% 50%

Manual to AMT TCp $0 $0 $0 $1,789 $1,761 $1,622 $1,994 $1,961 $1,929 $1,898

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

2.12.3.3 Automatic Transmission Powershift

We have estimated the cost of a powershift automatic transmission, relative to a manual 

transmission, based on an estimate by Tetra Tech of $15000 (retail, 2013$). Using that estimate, 

we divided by an RPE of 1.36 and converted to 2012$ to arrive at an estimated cost of $11670 

(DMC, 2012$, in 2018). We consider this technology to be on the flat portion of the learning 

curve (curve 12) and have applied a medium complexity ICM with short term markups through 

2022. The resultant technology costs, adoption rates and total cost applied to the package are 

shown in Table 2-151 for tractors.
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-151 Costs for a Powershift Automatic Transmission

Tractors (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Manual to AT 

powershift

DMC $11,670 $11,320 $10,981 $10,651 $10,438 $10,229 $10,025 $9,824 $9,628 $9,435

Manual to AT 

powershift

IC $3,528 $3,511 $3,493 $3,477 $3,466 $2,583 $2,576 $2,569 $2,562 $2,555

Manual to AT

powershift

TC $15,199 $14,831 $14,474 $14,128 $13,904 $12,812 $12,601 $12,393 $12,190 $11,990

Manual to AT 

powershift

Alt 

1a

Manual to AT 

powershift

Alt 3 10% 10% 10% 20% 20% 20% 30%

Manual to AT 

powershift

TCp $0 $0 $0 $1,413 $1,390 $1,281 $2,520 $2,479 $2,438 $3,597

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

2.12.3.4 Dual-clutch transmissions (DCT)

For vocational light/medium HD vehicles and for heavy HD urban and multipurpose 

vehicles, we estimate the cost of a move to a DCT from an automatic transmission to be cost 

neutral. For vocational heavy HD regional vehicles, we have estimated the cost of a DCT, 

relative to a manual transmission, as being equal to the move from a manual transmission to an 

AMT or $3694 (DMC, 2012$, in 2018, see 2.12.3.2 above). We consider this technology to be 

on the flat portion of the learning curve (curve 12) and have applied a medium complexity ICM 

with short term markups through 2022. The resultant technology costs, adoption rates and total 

cost applied to the package are shown in Table 2-154.

Table 2-152 Costs for a Dual Clutch Transmission (DCT)

Vocational Light/Medium/Heavy HD Urban/Multipurpose Vehicles (2012$) 

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Auto trans to DCT DMC $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

Auto trans to DCT IC $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

Auto trans to DCT TC $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

Auto trans to DCT Alt 1a

Auto trans to DCT Alt 3 5% 5% 5% 15% 15% 15% 5%

Auto trans to DCT TCp $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-153 Costs for a Dual Clutch Transmission (DCT)

Vocational Light/Medium HD Regional Vehicles (2012$) 

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Auto trans to DCT DMC $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

Auto trans to DCT IC $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

Auto trans to DCT TC $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

Auto trans to DCT Alt 1a

Auto trans to DCT Alt 3 5% 5% 5% 15% 15% 15% 10%

Auto trans to DCT TCp $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

Table 2-154 Costs for a Dual Clutch Transmission (DCT)

Vocational Heavy HD Regional Vehicles (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Manual to DCT DMC $3,694 $3,583 $3,476 $3,372 $3,304 $3,238 $3,173 $3,110 $3,048 $2,987

Manual to DCT IC $1,117 $1,111 $1,106 $1,101 $1,097 $818 $815 $813 $811 $809

Manual to DCT TC $4,811 $4,695 $4,582 $4,472 $4,401 $4,056 $3,989 $3,923 $3,859 $3,795

Manual to DCT Alt 

1a

Manual to DCT Alt 3 22% 22% 22% 33% 33% 33% 25%

Manual to DCT TCp $0 $0 $0 $984 $968 $892 $1,316 $1,295 $1,273 $949

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

For tractors, we have based our estimated cost of a DCT relative to a manual transmission 

on a Tetra Tech estimate of $17,500 (retail, 2013$). Using that estimate, we divided by an RPE 

of 1.36 and converted to 2012$ to arrive at an estimated cost of $12676 (DMC, 2012$, in 2018). 

We consider this technology to be on the flat portion of the learning curve (curve 12) and have 

applied a medium complexity ICM with short term markups through 2022. The resultant 

technology costs, adoption rates and total cost applied to the package are shown in Table 2-155

for tractors.

Table 2-155 Costs for a Dual Clutch Transmission (DCT)

Tractors (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Manual to DCT DMC $12,676 $12,296 $11,927 $11,569 $11,338 $11,111 $10,889 $10,671 $10,458 $10,248

Manual to DCT IC $3,832 $3,813 $3,794 $3,776 $3,765 $2,806 $2,798 $2,790 $2,783 $2,775

Manual to DCT TC $16,509 $16,109 $15,721 $15,346 $15,102 $13,917 $13,687 $13,461 $13,240 $13,024

Manual to DCT Alt 

1a

Manual to DCT Alt 3 5% 5% 5% 10% 10% 10% 10%

Manual to DCT TCp $0 $0 $0 $767 $755 $696 $1,369 $1,346 $1,324 $1,302

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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2.12.3.5 Improved transmissions – vocational vehicles

For this technology, we have relied on our light-duty technologies referred to as high 

efficiency gearbox (HEG), aggressive shift logic (ASL1) and early torque converter lockup 

(TORQ). Each of those technologies was estimated at $202, $27 and $25 (all are DMC, in 

2010$, in 2015 or 2017 (HEG)). For this analysis, we have used those estimates for ASL1 and 

TORQ, but have scaled upward the cost of HEG by 25 percent to account for differences 

between light-duty and HD. Converting to 2012$ results in costs for this technology of $316 

(DMC, 2012$, in 2021). We consider this technology to be on the flat portion of the learning 

curve (curve 13) and have applied a low complexity ICM with short term markups through 2022. 

The resultant technology costs, adoption rates and total cost applied to the package are shown in 

Table 2-156 for vocational vehicles.

Table 2-156 Costs of Improved Transmissions

All Vocational HD Vehicles (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Improved trans DMC $346 $336 $326 $316 $307 $297 $288 $283 $277 $271

Improved trans IC $57 $57 $57 $56 $56 $44 $44 $44 $44 $44

Improved trans TC $403 $393 $382 $372 $363 $342 $333 $327 $321 $315

Improved trans Alt 1a

Improved trans Alt 3 15% 15% 15% 30% 30% 30% 70%

Improved trans TCp $0 $0 $0 $56 $54 $51 $100 $98 $96 $221

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the 

package; alt=alternative; empty cells for adoption rates denote 0% adoption

2.12.3.6 Manual to automatic transmission, vocational heavy HD regional vehicles

For this technology, we have estimated the cost as equal to the cost for moving from a 

manual transmission to an AMT, as presented above, but have considered that cost to be 

applicable to MY2012, or $3694 (DMC, 2012$, in 2012). We consider this technology to be on 

the flat portion of the learning curve (curve 7) and have applied a medium complexity ICM with 

short term markups through 2018. The resultant technology costs, adoption rates and total cost 

applied to the package are shown in Table 2-157.
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-157 Cost for an Automatic Transmission

Vocational Heavy HD Regional Vehicles (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Manual to auto 

trans

DMC $3,141 $3,078 $3,017 $2,956 $2,897 $2,839 $2,782 $2,727 $2,699 $2,672

Manual to auto 

trans

IC $1,089 $812 $810 $808 $806 $804 $802 $800 $799 $798

Manual to auto 

trans

TC $4,230 $3,890 $3,826 $3,764 $3,703 $3,643 $3,584 $3,526 $3,498 $3,470

Manual to auto 

trans

Alt 

1a

Manual to auto 

trans

Alt 3 22% 22% 22% 33% 33% 33% 25%

Manual to auto 

trans

TCp $0 $0 $0 $828 $815 $801 $1,183 $1,164 $1,154 $868

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

2.12.3.7 8 speed transmission relative to a 6 speed, HD pickups & vans

We have based the cost of this technology on several values used in the light-duty 2017-

2025 final rule. In that rule, we presented costs for 6 to 8 speed automatic transmission, high 

efficiency gearbox (HEG) and aggressive shift logic (ASL1) as separate technologies. Here we 

are treating these technologies as separate for costing (since some metrics differ for each) but

considering them as being applied together as a complete group. As such, the cost for moving to 

an 8 speed transmission from the base 6 would always be the summation within any given year 

of the total costs shown in the tables that follow. For adding 2 gears, we have estimated the cost 

at $121 (DMC, 2012$, in 2012). We consider that technology to be on the flat portion of the 

learning curve (curve 7) and have applied medium complexity markups with near term markups 

through 2018. For HEG, we have estimated the cost at $263 (DMC, 2012$, in 2017). We 

consider this technology to be on the flat portion of the learning curve (curve 6) and have applied 

low complexity markups with near term markups through 2024. For shift logic, we have 

estimated the cost at $28 (DMC, 2012$, in 2015). We consider this technology to be on the flat 

portion of the learning curve (curve 8) and have applied low complexity markups with near term 

markups through 2018. The resultant costs for adding 2 gears are shown in Table 2-158, for 

HEG in Table 2-159 and for ASL1 in Table 2-160.

Table 2-158 Costs to Add 2 Transmission Gears

HD Pickups and Vans (2012$)

ITEM 2021 2022 2023 2024 2025 2026 2027

Move from 

6 to 8 gears

DMC $97 $95 $93 $91 $89 $88 $88

Move from 

6 to 8 gears

IC $34 $34 $34 $34 $34 $34 $34

Move from 

6 to 8 gears

TC $131 $129 $127 $125 $123 $123 $122

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-159 Costs for High Efficiency Gearbox (HEG)

HD Pickups and Vans (2012$)

ITEM 2021 2022 2023 2024 2025 2026 2027

High 

efficiency 

gearbox

DMC $232 $225 $221 $217 $212 $208 $204

High 

efficiency 

gearbox

IC $63 $63 $63 $63 $50 $50 $50

High 

efficiency 

gearbox

TC $296 $288 $284 $279 $262 $258 $254

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost

Table 2-160 Costs for Aggressive Shift Logic Level 1

HD Pickups and Vans (2012$)

ITEM 2021 2022 2023 2024 2025 2026 2027

Aggressive 

shift logic 1

DMC $25 $24 $24 $23 $23 $22 $22

Aggressive 

shift logic 1

IC $5 $5 $5 $5 $5 $5 $5

Aggressive 

shift logic 1

TC $30 $30 $29 $29 $28 $28 $28

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost

Table 2-161 Complete Cost of Moving from the Base 6 Speed to 8 Speed Transmission

2 Gears+HEG+ASL1

HD Pickups and Vans (2012$)

ITEM 2021 2022 2023 2024 2025 2026 2027

Move from 6speed to 

8speed Transmission

TC $457 $447 $440 $433 $414 $409 $403

Notes: TC=total cost.

2.12.4 Air Conditioning

2.12.4.1 Direct AC controls – vocational (all)

We have estimated the cost of this technology based on an estimate from TetraTech of 

$30 (retail, 2013$). Using that estimate we divided by a 1.36 RPE and converted to 2012$ to 

arrive at a cost of $22 (DMC, 2012$, in 2014). We consider this technology to be on the flat 

portion of the learning curve (curve 2) and have applied a low complexity ICM with short term 

markups through 2022. The resultant technology costs, adoption rates and total cost applied to 

the package are shown in Table 2-162.
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-162 Costs for Direct Air Conditioning Controls

All Vocational HD Vehicles (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

A/C direct DMC $19 $19 $18 $18 $18 $17 $17 $17 $17 $16

A/C direct IC $4 $4 $4 $4 $4 $3 $3 $3 $3 $3

A/C direct TC $23 $23 $22 $22 $22 $20 $20 $20 $20 $19

A/C direct Alt 1a

A/C direct Alt 3 100% 100% 100% 100% 100% 100% 100%

A/C direct TCp $0 $0 $0 $22 $22 $20 $20 $20 $20 $19

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the 

package; alt=alternative; empty cells for adoption rates denote 0% adoption

2.12.4.2 Indirect AC controls – tractors (all)

We have estimated the cost of this technology based on an estimate from TetraTech of 

$218 (retail, 2013$). Using that estimate we divided by a 1.36 RPE and converted to 2012$ to 

arrive at a cost of $158 (DMC, 2012$, in 2018). We consider this technology to be on the flat 

portion of the learning curve (curve 12) and have applied a low complexity ICM with short term 

markups through 2022. The resultant technology costs, adoption rates and total cost applied to 

the package are shown in Table 2-163.

Table 2-163 Costs for Indirect AC Controls

Tractors (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

A/C indirect DMC $158 $153 $148 $144 $141 $138 $135 $133 $130 $127

A/C indirect IC $28 $28 $28 $28 $28 $22 $22 $22 $22 $22

A/C indirect TC $186 $181 $176 $172 $169 $160 $157 $155 $152 $149

A/C indirect Alt 1a

A/C indirect Alt 3 10% 10% 10% 20% 20% 20% 30%

A/C indirect TCp $0 $0 $0 $17 $17 $16 $31 $31 $30 $45

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the 

package; alt=alternative; empty cells for adoption rates denote 0% adoption

2.12.5 Axles

2.12.5.1 6x2 Axle

We have estimated the cost of this technology based on an estimate from TetraTech of 

$250 (retail, 2013$). Using that estimate we divided by a 1.36 RPE and converted to 2012$ to 

arrive at a cost of $181 (DMC, 2012$, in 2018). We consider this technology to be on the flat 

portion of the learning curve (curve 12) and have applied a low complexity ICM with short term 

markups through 2022. The resultant technology costs, adoption rates and total cost applied to 

the package are shown in Table 2-164 for vocational heavy HD regional vehicles, in Table 2-165

for Class 8 tractors (day and sleeper cab) with low and mid roofs, and in Table 2-166 for Class 8 

tractors (day and sleeper cab) with high roofs.
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-164 Costs for 6x2 Axles

Vocational Heavy HD Regional Vehicles (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Axle 6x2 DMC $181 $176 $170 $165 $162 $159 $156 $152 $149 $146

Axle 6x2 IC $32 $32 $32 $32 $32 $25 $25 $25 $25 $25

Axle 6x2 TC $213 $208 $203 $197 $194 $184 $181 $178 $175 $172

Axle 6x2 Alt 1a

Axle 6x2 Alt 3 23% 23% 23% 30% 30% 30% 30%

Axle 6x2 TCp $0 $0 $0 $44 $44 $41 $54 $53 $52 $51

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the 

package; alt=alternative; empty cells for adoption rates denote 0% adoption

Table 2-165 Costs for 6x2 Axles

Class 8 Day Cab Low and Sleeper Cab Low/Mid Roof Tractors (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Axle 6x2 DMC $181 $176 $170 $165 $162 $159 $156 $152 $149 $146

Axle 6x2 IC $32 $32 $32 $32 $32 $25 $25 $25 $25 $25

Axle 6x2 TC $213 $208 $203 $197 $194 $184 $181 $178 $175 $172

Axle 6x2 Alt 1a

Axle 6x2 Alt 3 10% 10% 10% 20% 20% 20% 20%

Axle 6x2 TCp $0 $0 $0 $20 $19 $18 $36 $36 $35 $34

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the 

package; alt=alternative; empty cells for adoption rates denote 0% adoption

Table 2-166 Costs for 6x2 Axles

Class 8 Day Cab and Sleeper Cab High Roof Tractors (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Axle 6x2 DMC $181 $176 $170 $165 $162 $159 $156 $152 $149 $146

Axle 6x2 IC $32 $32 $32 $32 $32 $25 $25 $25 $25 $25

Axle 6x2 TC $213 $208 $203 $197 $194 $184 $181 $178 $175 $172

Axle 6x2 Alt 1a

Axle 6x2 Alt 3 20% 20% 20% 60% 60% 60% 60%

Axle 6x2 TCp $0 $0 $0 $39 $39 $37 $108 $107 $105 $103

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the 

package; alt=alternative; empty cells for adoption rates denote 0% adoption

2.12.5.2 Axle disconnect

We have estimated the cost of this technology based on an estimate from TetraTech of 

$140 (retail, 2013$). Using that estimate we divided by a 1.36 RPE and converted to 2012$ to 

arrive at a cost of $101 (DMC, 2012$, in all years). We consider this technology to be on the flat 

portion of the learning curve with no additional learning to occur (curve 1) and have applied a 

low complexity ICM with short term markups through 2022. The resultant technology costs, 

adoption rates and total cost applied to the package are shown in Table 2-167.
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-167 Costs for Axle Disconnect

Vocational Heavy HD Regional Vehicles (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Axle disconnect DMC $101 $101 $101 $101 $101 $101 $101 $101 $101 $101

Axle disconnect IC $18 $18 $18 $18 $18 $14 $14 $14 $14 $14

Axle disconnect TC $120 $120 $120 $120 $120 $116 $116 $116 $116 $116

Axle disconnect Alt 1a

Axle disconnect Alt 3 46% 46% 46% 61% 30% 30% 30%

Axle disconnect TCp $0 $0 $0 $55 $55 $53 $71 $35 $35 $35

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the 

package; alt=alternative; empty cells for adoption rates denote 0% adoption

2.12.5.3 Axle downspeed

We have estimated the cost of this technology based on engineering judgment at $50 

(DMC, 2013$, in 2018). This DMC is expected to cover development and some testing and 

integration work since there is no real hardware required for this technology. Converting this 

DMC to 2012$ results in a $49 cost (DMC, 2012$, in 2018). We consider this technology to be 

on the flat portion of the learning curve (curve 12) and have applied a low complexity ICM with 

short term markups through 2022. The resultant technology costs, adoption rates and total cost 

applied to the package are shown in Table 2-168.

Table 2-168 Costs for Axle Downspeeding

Tractors (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Axle downspeed DMC $49 $48 $46 $45 $44 $43 $42 $41 $41 $40

Axle downspeed IC $9 $9 $9 $9 $9 $7 $7 $7 $7 $7

Axle downspeed TC $58 $57 $55 $54 $53 $50 $49 $48 $47 $47

Axle downspeed Alt 1a

Axle downspeed Alt 3 20% 20% 20% 40% 40% 40% 60%

Axle downspeed TCp $0 $0 $0 $11 $11 $10 $20 $19 $19 $28

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the 

package; alt=alternative; empty cells for adoption rates denote 0% adoption

2.12.5.4 Low friction axle lubes

We have estimated the cost of this technology based on an estimate from TetraTech of 

$250 (retail, 2013$), an estimate applicable to tractors having 3 axles. Using that estimate we 

divided by a 1.36 RPE and converted to 2012$ to arrive at a cost of $181 (DMC, 2012$, in 

2018). We consider this estimate to be applicable also to vocational HH vehicles since these 

generally have 3 axles. For vocational light/medium HD vehicles, which generally have 2 axles, 

we have estimated the DMC at 2/3 the vocational heavy HD/tractor cost, or $121 (DMC, 2012$, 

in 2018). We consider this technology to be on the flat portion of the learning curve (curve 12) 

and have applied a low complexity ICM with short term markups through 2022. The resultant 

technology costs, adoption rates and total cost applied to the package are shown in Table 2-169

for vocational light and medium HD vehicles and in Table 2-170 for vocational heavy HD 

vehicles, and in Table 2-171 for tractors.
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-169 Costs for Low Friction Axle Lubes

Vocational Light/Medium HD Urban/Multipurpose/Regional Vehicles (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Axle low friction lubes DMC $121 $117 $114 $110 $108 $106 $104 $102 $100 $98

Axle low friction lubes IC $22 $22 $21 $21 $21 $17 $17 $17 $17 $17

Axle low friction lubes TC $142 $139 $135 $132 $129 $123 $121 $118 $116 $114

Axle low friction lubes Alt 1a

Axle low friction lubes Alt 3 75% 75% 75% 75% 75% 75% 75%

Axle low friction lubes TCp $0 $0 $0 $99 $97 $92 $90 $89 $87 $86

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

Table 2-170 Costs for Low Friction Axle Lubes

Vocational Heavy HD Urban/Multipurpose/Regional Vehicles (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Axle low friction lubes DMC $181 $176 $170 $165 $162 $159 $156 $152 $149 $146

Axle low friction lubes IC $32 $32 $32 $32 $32 $25 $25 $25 $25 $25

Axle low friction lubes TC $213 $208 $203 $197 $194 $184 $181 $178 $175 $172

Axle low friction lubes Alt 1a

Axle low friction lubes Alt 3 75% 75% 75% 75% 75% 75% 75%

Axle low friction lubes TCp $0 $0 $0 $148 $146 $138 $136 $133 $131 $129

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

Table 2-171 Costs for Low Friction Axle Lubes

Tractors (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Axle low friction lubes DMC $181 $176 $170 $165 $162 $159 $156 $152 $149 $146

Axle low friction lubes IC $32 $32 $32 $32 $32 $25 $25 $25 $25 $25

Axle low friction lubes TC $213 $208 $203 $197 $194 $184 $181 $178 $175 $172

Axle low friction lubes Alt 1a

Axle low friction lubes Alt 3 20% 20% 20% 40% 40% 40% 40%

Axle low friction lubes TCp $0 $0 $0 $39 $39 $37 $72 $71 $70 $69

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

2.12.6 Idle Reduction

2.12.6.1 Auxiliary power units (APU)

We have estimated the cost of this technology based on the APU costs discussed in the 

Phase 1 rule. That technology was estimated at $4586 (DMC, 2008$, in 2014). With updates, 

that cost becomes $4853 (DMC, 2012$, in 2014) for Phase 2. We consider this technology to be 

on the flat portion of the learning curve (curve 2) and have applied a low complexity ICM with 

short term markups through 2022. The resultant technology costs, adoption rates and total cost 

applied to the package are shown in Table 2-172.
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-172 Costs for Auxiliary Power Units (APU)

Sleeper Cab Tractors (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

APU DMC $4,296 $4,210 $4,126 $4,043 $3,962 $3,883 $3,805 $3,729 $3,692 $3,655

APU IC $859 $857 $856 $855 $854 $674 $673 $673 $673 $672

APU TC $5,154 $5,067 $4,982 $4,899 $4,817 $4,557 $4,479 $4,402 $4,365 $4,327

APU Alt 

1a

30% 30% 30% 30% 30% 30% 30% 30% 30% 30%

APU Alt 3 30% 30% 30% 70% 70% 70% 80% 90% 90% 90%

APU TCp $0 $0 $0 $1,959 $1,927 $1,823 $2,239 $2,641 $2,619 $2,596

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative

2.12.6.2 Neutral idle

We have estimated the cost of this technology based on engineering judgment at $10 

(retail, 2013$). Using that estimate, we have divided by a 1.36 RPE and converted to 2012$ to 

arrive at a $7 cost (DMC, 2012$, in all years). This DMC is expected to cover development and 

some testing and integration work since there is no real hardware required for this technology. 

We consider this technology to be on the flat portion of the learning curve with no additional 

learning to occur (curve 1) and have applied a low complexity ICM with short term markups 

through 2022. The resultant technology costs, adoption rates and total cost applied to the package 

are shown in Table 2-173 and Table 2-174 for vocational vehicles.

Table 2-173 Costs for Neutral Idle Technology

Vocational Light/Medium HD Urban Vehicles (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Neutral idle DMC $7 $7 $7 $7 $7 $7 $7 $7 $7 $7

Neutral idle IC $1 $1 $1 $1 $1 $1 $1 $1 $1 $1

Neutral idle TC $9 $9 $9 $9 $9 $8 $8 $8 $8 $8

Neutral idle Alt 1a

Neutral idle Alt 3 70% 70% 70% 85% 85% 85% 25%

Neutral idle TCp $0 $0 $0 $6 $6 $6 $7 $7 $7 $2

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the 

package; alt=alternative; empty cells for adoption rates denote 0% adoption

Table 2-174 Costs for Neutral Idle Technology

Vocational Light/Medium/Heavy HD Multipurpose Vehicles and

Vocational Light/Medium HD Regional Vehicles

And Vocational Heavy HD Urban Vehicles (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Neutral idle DMC $7 $7 $7 $7 $7 $7 $7 $7 $7 $7

Neutral idle IC $1 $1 $1 $1 $1 $1 $1 $1 $1 $1

Neutral idle TC $9 $9 $9 $9 $9 $8 $8 $8 $8 $8

Neutral idle Alt 1a

Neutral idle Alt 3 70% 70% 70% 85% 85% 85% 30%

Neutral idle TCp $0 $0 $0 $6 $6 $6 $7 $7 $7 $2

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the 

package; alt=alternative; empty cells for adoption rates denote 0% adoption
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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2.12.6.3 Stop-start

We have estimated the cost of this technology based on several cost estimates. First, an 

estimate from TetraTech of $700 (retail, 2013$) for gasoline HD pickups and vans and $1500 

(retail, 2013$) for diesel HD pickups and vans. Using these values, we divided by a 1.36 RPE 

and converted to 2012$ to arrive at $507 (DMC, 2012$, in 2021) and $1087 (DMC, 2012$, in 

2021) which were considered appropriate for vocational MH and HH vehicles, respectively. To 

these estimates, we have added the costs for improved accessories used for HD pickups and vans 

of $124 (DMC, 2012$, in 2015) which is based on values from the 2017-2025 light-duty FRM. 

However, to account for the heavier vocational vehicles relative to the HD pickup and vans, we 

have scaled upward the improved accessory value by 50 percent to arrive at a cost of $186 

(DMC, 2012$, in 2015). We have then added these values to arrive at costs of $693 (DMC, 

2012$, in 2021) and $1272 (DMC, 2012$, in 2021) and have applied the lower cost to vocational 

medium HD vehicles and the higher cost to vocational heavy HD vehicles. For vocational light

HD, we have used the stop-start cost for the 2017-2025 rule for LD pickups ($377 DMC, 2012$, 

in 2015) but have scaled upward that value by 25 percent to account for the weight difference 

between the LD and vocational light HD vehicles. Doing this results in a cost of $471 (DMC, 

2012$, in 2021). Adding to that the $186 value for improved accessories mentioned earlier gives 

the resultant vocational light HD cost of $656 (DMC, 2012$, in 2021). We consider all of these 

technologies to be on the flat portion of the learning curve (curve 13) and have applied a medium 

complexity ICM with short term markups through 2022. The resultant technology costs, adoption 

rates and total cost applied to the package are shown in Table 2-175 for vocational light HD, 

Table 2-176 for vocational medium HD, and in Table 2-177 for vocational heavy HD vehicles.

Table 2-175 Costs for Stop-start

Vocational Light HD Urban/Multipurpose/Regional Vehicles (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Stop-start DMC $719 $698 $677 $656 $637 $618 $599 $587 $575 $564

Stop-start IC $202 $201 $200 $198 $197 $147 $146 $146 $145 $145

Stop-start TC $921 $898 $876 $855 $834 $764 $745 $733 $721 $709

Stop-start Alt 1a

Stop-start Alt 3 5% 5% 5% 15% 15% 15% 70%

Stop-start TCp $0 $0 $0 $43 $42 $38 $112 $110 $108 $496

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the 

package; alt=alternative; empty cells for adoption rates denote 0% adoption

Table 2-176 Costs for Stop-start

Vocational Medium HD Urban/Multipurpose/Regional Vehicles (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Stop-start DMC $759 $736 $714 $693 $672 $652 $632 $620 $607 $595

Stop-start IC $213 $212 $211 $209 $208 $155 $154 $154 $153 $153

Stop-start TC $972 $948 $925 $902 $880 $807 $786 $773 $761 $748

Stop-start Alt 1a

Stop-start Alt 3 5% 5% 5% 15% 15% 15% 70%

Stop-start TCp $0 $0 $0 $45 $44 $40 $118 $116 $114 $524

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the 

package; alt=alternative; empty cells for adoption rates denote 0% adoption
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-177 Costs for Stop-start

Vocational Heavy HD Urban/Multipurpose/Regional Vehicles (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Stop-start DMC $1,394 $1,352 $1,312 $1,272 $1,234 $1,197 $1,161 $1,138 $1,115 $1,093

Stop-start IC $391 $389 $387 $385 $383 $284 $283 $282 $282 $281

Stop-start TC $1,785 $1,741 $1,698 $1,657 $1,617 $1,482 $1,444 $1,420 $1,397 $1,374

Stop-start Alt 

1a

Stop-start Alt 3 15% 15% 15% 70%

Stop-start TCp $0 $0 $0 $0 $0 $0 $217 $213 $210 $962

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

For HD pickups and vans, we have based our costs for stop-start systems on the values 

used in the light-duty 2017-2025 final rule, but have scaled upward those costs by 25 percent to 

account for the larger and harder starting HD engines. Using this approach and converting to 

2012$ results in a cost of $471 (DMC, 2012$, in 2015). We consider this technology to be on the 

steep portion of the learning curve (curve 9, note the different year of cost-applicability relative 

to the vocational cost discussed above) and have applied medium complexity markups with near 

term markups through 2018. The resultant costs for HD pickups and vans are shown in Table 

2-178.

Table 2-178 Costs of Stop-start

HD Pickups and Vans (2012$)

ITEM 2021 2022 2023 2024 2025 2026 2027

Stop-start DMC $404 $392 $380 $369 $358 $351 $344

Stop-start IC $134 $134 $134 $133 $133 $133 $132

Stop-start TC $539 $526 $514 $502 $491 $483 $476

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost

2.12.7 Electrification (strong/mild HEV, full EV)

2.12.7.1 Strong hybrid electric vehicle (strong HEV)

We have estimated the cost of this technology using the costs estimated in the 2017-2025 

light-duty rule for a light-duty pickup strong HEV. There we estimated the cost at $2729 (DMC, 

2010$, in 2021) for a LD truck with a 5200 pound curb weight. We have then scaled upward that 

value using the ratio of test weights for HD pickups in our MY2014 market file (8739 pounds) to 

the test weight of the 5200 pound LD truck (5500 pounds). The resultant strong hybrid costs 

become $4335 (DMC, 2012$, in 2021) for HD pickups and vans. We consider this technology to 

be on the steep portion of the learning curve today but on the flat portion by 2021 (curve 11) and 

have applied high complexity level 1 with short term markups through 2024. The resultant 

technology costs are shown in Table 2-179 for HD pickups and vans.
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-179 Costs of Strong Hybrid

HD Pickups and Vans (2012$)

ITEM 2021 2022 2023 2024 2025 2026 2027

Strong HEV DMC $4,335 $4,205 $4,079 $3,957 $3,838 $3,723 $3,648

Strong HEV IC $2,443 $2,435 $2,427 $2,419 $1,482 $1,478 $1,476

Strong HEV TC $6,779 $6,640 $6,506 $6,376 $5,320 $5,201 $5,124

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost

For vocational vehicle strong hybrids, we have scaled upward from the HD pickup and 

van values using best estimates of curb weights. For vocational vehicles, we have used curb 

weights of 16,000 for light HD, 25,150 for medium HD and 42,000 for heavy HD relative to a 

6500 pound value for HD pickups. Scaling based on curb weight here should provide an 

acceptable scaling of costs with battery and motor sizes since those are generally directly

correlated with the weight of the vehicle itself. Using these scaling factors results in costs for 

complete hybrid systems for light, medium and heavy HD, respectively, of $10,672, $16,774 and 

$28,013 (DMC, 2012$, in 2021). We consider this technology to be on the steep portion of the 

learning curve today but on the flat portion by 2021 (curve 11) and have applied high complexity

level 1 with short term markups through 2022. The resultant technology costs, adoption rates and 

total cost applied to the package are shown are shown in Table 2-180 for light HD, in Table 

2-181 for medium HD and in Table 2-182 for heavy HD vocational vehicles.

Table 2-180 Costs for Strong Hybrid

Vocational Light HD Urban/Multipurpose Vehicles (2012$)

ITEM 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Strong 

HEV

DMC $16,674 $13,340 $13,340 $10,672 $10,351 $10,041 $9,740 $9,448 $9,164 $8,981

Strong 

HEV

IC $4,975 $4,731 $4,731 $4,536 $4,512 $2,849 $2,838 $2,827 $2,817 $2,810

Strong 

HEV

TC $21,649 $18,070 $18,070 $15,207 $14,864 $12,890 $12,578 $12,275 $11,981 $11,791

Strong 

HEV

Alt 

1a

Strong 

HEV

Alt 3 4% 4% 4% 7% 7% 7% 18%

Strong 

HEV

TCp $0 $0 $0 $547 $535 $464 $906 $884 $863 $2,122

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-181 Costs for Strong Hybrid

Vocational Medium HD Urban/Multipurpose Vehicles (2012$)

ITEM 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Strong 

HEV

DMC $26,210 $20,968 $20,968 $16,774 $16,271 $15,783 $15,310 $14,850 $14,405 $14,117

Strong 

HEV

IC $7,820 $7,436 $7,436 $7,129 $7,093 $4,478 $4,461 $4,444 $4,428 $4,418

Strong 

HEV

TC $34,030 $28,404 $28,404 $23,904 $23,364 $20,262 $19,771 $19,295 $18,833 $18,534

Strong 

HEV

Alt 

1a

Strong 

HEV

Alt 3 4% 4% 4% 7% 7% 7% 18%

Strong 

HEV

TCp $0 $0 $0 $861 $841 $729 $1,424 $1,389 $1,356 $3,336

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

Table 2-182 Costs for Strong Hybrid

Vocational Heavy HD Urban/Multipurpose Vehicles (2012$)

ITEM 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Strong 

HEV

DMC $43,770 $35,016 $35,016 $28,013 $27,173 $26,357 $25,567 $24,800 $24,056 $23,575

Strong 

HEV

IC $13,059 $12,418 $12,418 $11,906 $11,844 $7,479 $7,450 $7,422 $7,395 $7,377

Strong 

HEV

TC $56,829 $47,435 $47,435 $39,919 $39,017 $33,836 $33,017 $32,222 $31,451 $30,952

Strong 

HEV

Alt 

1a

Strong 

HEV

Alt 3 4% 4% 4% 7% 7% 7% 18%

Strong 

HEV

TCp $0 $0 $0 $1,437 $1,405 $1,218 $2,377 $2,320 $2,264 $5,571

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

2.12.7.2 Mild hybrid electric vehicle (mild HEV)

We have estimated the cost of this technology using the costs estimated in the 2017-2025 

light-duty rule for a light-duty pickup mild HEV. There we estimated the cost at $983 (DMC, 

2010$, in 2021) for a LD truck with a 3500 pound curb weight. We have then scaled upward that 

value using the ratio of curb weights for HD pickups of 6500 pounds to the 3500 pound curb 

weight. The resultant mild hybrid costs become $1894 (DMC, 2012$, in 2017) for HD pickups 

and vans. We consider this technology to be on the flat portion of the learning curve (curve 6) 

and have applied high complexity level 1 with short term markups through 2024. The resultant 

technology costs are shown in Table 2-183 for HD pickups and vans.
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-183 Costs of Mild Hybrid

HD Pickups and Vans (2012$)

ITEM 2021 2022 2023 2024 2025 2026 2027

Mild HEV DMC $1,677 $1,626 $1,594 $1,562 $1,531 $1,500 $1,470

Mild HEV IC $1,053 $1,050 $1,048 $1,046 $643 $642 $641

Mild HEV TC $2,730 $2,677 $2,642 $2,608 $2,173 $2,142 $2,111

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost

For tractors, we have estimated the cost of this technology based on an estimate from 

TetraTech of $20,000 (retail, 2013$). Using that value, we divided by a 1.36 RPE and converted 

to 2012$ to arrive at a cost of $14,487 (DMC, 2012$, in 2018). We consider this technology to 

be on the flat portion of the learning curve (curve 12) and have applied a high complexity level 1 

markup with short term markups through 2025. The resultant technology costs are shown in 

Table 2-184 (note that this technology is not expected to be used so the application rate is 0%).

Table 2-184 Costs for Mild Hybrid

Tractors (2012$)

ITEM 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Mild 

HEV

DMC $14,487 $14,052 $13,631 $13,222 $12,958 $12,698 $12,444 $12,196 $11,952 $11,713

Mild 

HEV

IC $6,157 $6,125 $6,094 $6,065 $6,045 $6,026 $6,008 $5,989 $3,806 $3,798

Mild 

HEV

TC $20,644 $20,178 $19,725 $19,287 $19,003 $18,725 $18,452 $18,185 $15,758 $15,510

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative

2.12.7.3 Full electric vehicle (Full EV)

For vocational vehicle full EVs, we have used an estimate of $77888 (retail, 2013$) 

based on an estimate from The West Coast Collaborative.176 Using that value, we divided by a 

1.36 RPE and converted to 2012$ to arrive at a cost of $56,418 (DMC, 2012$, in 2014). We 

consider this technology to be on the steep portion of the learning curve (curve 4) and have 

applied a high complexity level 1 markup with short term markups through 2028. The resultant 

technology costs are shown in Table 2-185.

Table 2-185 Costs of Full Electric Vehicle

Vocational Light/Medium HD (Urban/Multipurpose/Regional) Vehicles (2012$)

ITEM 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Full 

EV

DMC $36,108 $35,025 $33,974 $32,955 $31,966 $31,007 $30,077 $29,174 $28,591 $28,019

Full 

EV

IC $22,492 $22,413 $22,336 $22,262 $22,189 $22,119 $22,051 $21,985 $21,942 $21,900

Full 

EV

TC $58,600 $57,438 $56,310 $55,216 $54,155 $53,126 $52,128 $51,159 $50,533 $49,920

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost

For day cab tractor full EVs, we have used an estimate of $203,000 (retail, 2012$) based 

on an estimate from the California Energy Commission. Using that value, we divided by a 1.36 
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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RPE to arrive at a cost of $149,265 (DMC, 2012$, in 2014). We consider this technology to be 

on the steep portion of the learning curve (curve 4) and have applied a high complexity level 1 

markup with short term markups through 2028. The resultant technology costs are shown in 

Table 2-186.

Table 2-186 Costs for Full Electric Vehicle

Day Cab Tractors (2012$)

ITEM 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Full 

EV

DMC $95,529 $92,664 $89,884 $87,187 $84,572 $82,034 $79,573 $77,186 $75,642 $74,130

Full 

EV

IC $59,507 $59,297 $59,094 $58,897 $58,705 $58,520 $58,340 $58,165 $58,052 $57,941

Full 

EV

TC $155,036 $151,961 $148,978 $146,084 $143,277 $140,554 $137,913 $135,351 $133,694 $132,071

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost

2.12.8 Tires

2.12.8.1 Lower rolling resistance tires ($/tire)

We have estimated the cost of lower rolling resistance tires based on an estimate from 

TetraTech of $30 (retail, 2013$). Using that estimate we divided by a 1.36 RPE and converted to 

2012$ to arrive at a cost of $22 (DMC, 2012$) but consider that cost valid in different years 

depending on the level of rolling resistance. For LRR tires level 1 and 2, we consider that $22 

value valid in 2014, level 3 in 2018, and level 4 in 2021. We consider this technology to be on 

the flat portion of the curve with LRR tires level 1 and 2 on curve 4, LRR tires level 3 on curve 

12 and LRR tires level 4 on curve 13. We have applied a low complexity markup to LRR tires 

levels 1 and 3 with short term markups through 2022. For LRR tires level 3, we have applied a 

medium complexity markup with short term markups through 2025 and, for LRR tires level 4, 

we have applied a medium complexity markup with short term markups through 2028. As a 

result, despite using the same DMC for each level of rolling resistance, our tire costs can vary

considerably year-over-year for each of the 4 levels of rolling resistance considered. The 

resultant costs on a per-tire basis are shown in Table 2-187. Table 2-188 through Table 2-202

show the costs per vehicle depending on the number of tires present on the vehicle. 
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-187 Costs for Lower Rolling Resistance Tires

at each LRR level (2012$/tire)

ITEM 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

LRR –

level 1

DMC $19 $19 $18 $18 $18 $17 $17 $17 $17 $16

LRR –

level 2

DMC $19 $19 $18 $18 $18 $17 $17 $17 $17 $16

LRR –

level 3

DMC $22 $21 $20 $20 $19 $19 $19 $18 $18 $18

LRR –

level 4

DMC $24 $23 $22 $22 $21 $20 $20 $19 $19 $19

LRR –

level 1

IC $4 $4 $4 $4 $4 $3 $3 $3 $3 $3

LRR –

level 2

IC $4 $4 $4 $4 $4 $3 $3 $3 $3 $3

LRR –

level 3

IC $7 $7 $7 $6 $6 $6 $6 $6 $5 $5

LRR –

level 4

IC $7 $7 $7 $7 $7 $7 $6 $6 $6 $6

LRR –

level 1

TC $23 $23 $22 $22 $22 $20 $20 $20 $20 $19

LRR –

level 2

TC $23 $23 $22 $22 $22 $20 $20 $20 $20 $19

LRR –

level 3

TC $28 $28 $27 $26 $26 $25 $25 $25 $23 $22

LRR –

level 4

TC $30 $30 $29 $28 $28 $27 $26 $26 $25 $25

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost

2.12.8.2 Lower RR steer tires, All Vocational Vehicles

Table 2-188 Costs for Lower Rolling Resistance Steer Tires

All Vocational Vehicles

(2012$/vehicle @ 2 tires/vehicle)

ITEM 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

LRR –

level 1

TC $46 $45 $45 $44 $43 $41 $40 $39 $39 $39

LRR –

level 2

TC $46 $45 $45 $44 $43 $41 $40 $39 $39 $39

LRR –

level 3

TC $57 $55 $54 $53 $52 $51 $50 $49 $45 $45

LRR –

level 4

TC $61 $59 $58 $57 $55 $54 $53 $52 $51 $50

LRR –

level 1

Alt 

1a

100% 100% 100% 100% 100% 100% 100% 100% 100% 100%

LRR –

level 2

Alt 

1a

LRR –

level 3

Alt 

1a

LRR –

level 4

Alt 

1a

LRR – Alt 3 100% 100% 100% 20% 20% 20% 10% 10% 10% 0%
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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level 1

LRR –

level 2

Alt 3

LRR –

level 3

Alt 3 80% 80% 80% 30% 30% 30% 20%

LRR –

level 4

Alt 3 60% 60% 60% 80%

LRR –

level 1

TCp $0 $0 $0 -$35 -$35 -$33 -$36 -$35 -$35 -$39

LRR –

level 2

TCp $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

LRR –

level 3

TCp $0 $0 $0 $42 $41 $41 $15 $15 $14 $9

LRR –

level 4

TCp $0 $0 $0 $0 $0 $0 $32 $31 $31 $40

Notes: TC=total cost; TCp=total cost applied to the package; alt=alternative; empty cells for adoption rates denote 

0% adoption

2.12.8.3 Lower RR drive tires, All Vocational Light/Medium HD Vehicles

Table 2-189 Costs for Lower Rolling Resistance Drive Tires

Vocational Light/Medium HD Vehicles

(2012$/vehicle @ 4 tires/vehicle)

ITEM 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

LRR –

level 1

TC $92 $91 $89 $88 $86 $82 $80 $79 $78 $78

LRR –

level 2

TC $92 $91 $89 $88 $86 $82 $80 $79 $78 $78

LRR –

level 3

TC $113 $110 $108 $105 $104 $102 $100 $99 $91 $89

LRR –

level 4

TC $122 $119 $116 $113 $110 $108 $105 $104 $102 $100

LRR –

level 1

Alt 

1a

100% 100% 100% 100% 100% 100% 100% 100% 100% 100%

LRR –

level 2

Alt 

1a

LRR –

level 3

Alt 

1a

LRR –

level 4

Alt 

1a

LRR –

level 1

Alt 3 100% 100% 100% 50% 50% 50% 20% 20% 20% 10%

LRR –

level 2

Alt 3 50% 50% 50% 50% 50% 50% 25%

LRR –

level 3

Alt 3 30% 30% 30% 50%

LRR –

level 4

Alt 3 15%

LRR –

level 1

TCp $0 $0 $0 -$44 -$43 -$41 -$64 -$63 -$63 -$70

LRR –

level 2

TCp $0 $0 $0 $44 $43 $41 $40 $39 $39 $19

LRR – TCp $0 $0 $0 $0 $0 $0 $30 $30 $27 $45
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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level 3

LRR –

level 4

TCp $0 $0 $0 $0 $0 $0 $0 $0 $0 $15

Notes: TC=total cost; TCp=total cost applied to the package; alt=alternative; empty cells for adoption rates denote 

0% adoption

2.12.8.4 Lower RR drive tires, Vocational Heavy HD Vehicles

Table 2-190 Costs for Lower Rolling Resistance Drive Tires

Vocational Heavy HD Vehicles

(2012$/vehicle @ 8 tires/vehicle)

ITEM 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

LRR –

level 1

TC $185 $182 $178 $175 $173 $163 $160 $158 $156 $155

LRR –

level 2

TC $185 $182 $178 $175 $173 $163 $160 $158 $156 $155

LRR –

level 3

TC $226 $221 $216 $210 $207 $204 $201 $198 $182 $179

LRR –

level 4

TC $244 $238 $232 $226 $221 $216 $210 $207 $204 $201

LRR –

level 1

Alt 

1a

100% 100% 100% 100% 100% 100% 100% 100% 100% 100%

LRR –

level 2

Alt 

1a

LRR –

level 3

Alt 

1a

LRR –

level 4

Alt 

1a

LRR –

level 1

Alt 3 100% 100% 100% 50% 50% 50% 20% 20% 20% 10%

LRR –

level 2

Alt 3 50% 50% 50% 50% 50% 50% 25%

LRR –

level 3

Alt 3 30% 30% 30% 50%

LRR –

level 4

Alt 3 15%

LRR –

level 1

TCp $0 $0 $0 -$88 -$86 -$82 -$128 -$126 -$125 -$140

LRR –

level 2

TCp $0 $0 $0 $88 $86 $82 $80 $79 $78 $39

LRR –

level 3

TCp $0 $0 $0 $0 $0 $0 $60 $59 $54 $89

LRR –

level 4

TCp $0 $0 $0 $0 $0 $0 $0 $0 $0 $30

Notes: TC=total cost; TCp=total cost applied to the package; alt=alternative; empty cells for adoption rates denote 

0% adoption
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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2.12.8.5 Lower RR steer tires, Day cab low roof tractors

Table 2-191 Costs for Lower Rolling Resistance Steer Tires

Day Cab Low Roof Tractors

(2012$/vehicle @ 2 tires/vehicle)

ITEM 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

LRR –

level 1

TC $46 $45 $45 $44 $43 $41 $40 $39 $39 $39

LRR –

level 2

TC $46 $45 $45 $44 $43 $41 $40 $39 $39 $39

LRR –

level 3

TC $57 $55 $54 $53 $52 $51 $50 $49 $45 $45

LRR –

level 4

TC $61 $59 $58 $57 $55 $54 $53 $52 $51 $50

LRR –

level 1

Alt 

1a

50% 50% 50% 50% 50% 50% 50% 50% 50% 50%

LRR –

level 2

Alt 

1a

10% 10% 10% 10% 10% 10% 10% 10% 10% 10%

LRR –

level 3

Alt 

1a

LRR –

level 4

Alt 

1a

LRR –

level 1

Alt 3 50% 50% 50% 60% 60% 60% 50% 50% 50% 20%

LRR –

level 2

Alt 3 10% 10% 10% 25% 25% 25% 30% 30% 30% 50%

LRR –

level 3

Alt 3 10% 10% 10% 15% 15% 15% 25%

LRR –

level 4

Alt 3

LRR –

level 1

TCp $0 $0 $0 $4 $4 $4 $0 $0 $0 -$12

LRR –

level 2

TCp $0 $0 $0 $7 $6 $6 $8 $8 $8 $16

LRR –

level 3

TCp $0 $0 $0 $5 $5 $5 $8 $7 $7 $11

LRR –

level 4

TCp $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

Notes: TC=total cost; TCp=total cost applied to the package; alt=alternative; empty cells for adoption rates denote 

0% adoption

2.12.8.6 Lower RR steer tires, Day cab high roof tractors

Table 2-192 Costs for Lower Rolling Resistance Steer Tires

Day Cab High Roof Tractors

(2012$/vehicle @ 2 tires/vehicle)

ITEM 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

LRR –

level 1

TC $46 $45 $45 $44 $43 $41 $40 $39 $39 $39

LRR –

level 2

TC $46 $45 $45 $44 $43 $41 $40 $39 $39 $39

LRR – TC $57 $55 $54 $53 $52 $51 $50 $49 $45 $45
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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level 3

LRR –

level 4

TC $61 $59 $58 $57 $55 $54 $53 $52 $51 $50

LRR –

level 1

Alt 

1a

70% 70% 70% 70% 70% 70% 70% 70% 70% 70%

LRR –

level 2

Alt 

1a

20% 20% 20% 20% 20% 20% 20% 20% 20% 20%

LRR –

level 3

Alt 

1a

LRR –

level 4

Alt 

1a

LRR –

level 1

Alt 3 70% 70% 70% 60% 60% 60% 50% 50% 50% 20%

LRR –

level 2

Alt 3 20% 20% 20% 25% 25% 25% 30% 30% 30% 50%

LRR –

level 3

Alt 3 10% 10% 10% 15% 15% 15% 25%

LRR –

level 4

Alt 3

LRR –

level 1

TCp $0 $0 $0 -$4 -$4 -$4 -$8 -$8 -$8 -$19

LRR –

level 2

TCp $0 $0 $0 $2 $2 $2 $4 $4 $4 $12

LRR –

level 3

TCp $0 $0 $0 $5 $5 $5 $8 $7 $7 $11

LRR –

level 4

TCp $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

Notes: TC=total cost; TCp=total cost applied to the package; alt=alternative; empty cells for adoption rates denote 

0% adoption

2.12.8.7 Lower RR steer tires, Sleeper cab low/mid roof tractors

Table 2-193 Costs for Lower Rolling Resistance Steer Tires

Sleeper Cab Low/Mid Roof Tractors

(2012$/vehicle @ 2 tires/vehicle)

ITEM 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

LRR –

level 1

TC $46 $45 $45 $44 $43 $41 $40 $39 $39 $39

LRR –

level 2

TC $46 $45 $45 $44 $43 $41 $40 $39 $39 $39

LRR –

level 3

TC $57 $55 $54 $53 $52 $51 $50 $49 $45 $45

LRR –

level 4

TC $61 $59 $58 $57 $55 $54 $53 $52 $51 $50

LRR –

level 1

Alt 

1a

60% 60% 60% 60% 60% 60% 60% 60% 60% 60%

LRR –

level 2

Alt 

1a

10% 10% 10% 10% 10% 10% 10% 10% 10% 10%

LRR –

level 3

Alt 

1a

LRR –

level 4

Alt 

1a

LRR – Alt 3 60% 60% 60% 60% 60% 60% 50% 50% 50% 20%
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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level 1

LRR –

level 2

Alt 3 10% 10% 10% 25% 25% 25% 30% 30% 30% 50%

LRR –

level 3

Alt 3 10% 10% 10% 15% 15% 15% 25%

LRR –

level 4

Alt 3

LRR –

level 1

TCp $0 $0 $0 $0 $0 $0 -$4 -$4 -$4 -$16

LRR –

level 2

TCp $0 $0 $0 $7 $6 $6 $8 $8 $8 $16

LRR –

level 3

TCp $0 $0 $0 $5 $5 $5 $8 $7 $7 $11

LRR –

level 4

TCp $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

Notes: TC=total cost; TCp=total cost applied to the package; alt=alternative; empty cells for adoption rates denote 

0% adoption

2.12.8.8 Lower RR steer tires, Sleeper cab high roof tractors

Table 2-194 Costs for Lower Rolling Resistance Steer Tires

Sleeper Cab High Roof Tractors

(2012$/vehicle @ 2 tires/vehicle)

ITEM 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

LRR –

level 1

TC $46 $45 $45 $44 $43 $41 $40 $39 $39 $39

LRR –

level 2

TC $46 $45 $45 $44 $43 $41 $40 $39 $39 $39

LRR –

level 3

TC $57 $55 $54 $53 $52 $51 $50 $49 $45 $45

LRR –

level 4

TC $61 $59 $58 $57 $55 $54 $53 $52 $51 $50

LRR –

level 1

Alt 

1a

70% 70% 70% 70% 70% 70% 70% 70% 70% 70%

LRR –

level 2

Alt 

1a

20% 20% 20% 20% 20% 20% 20% 20% 20% 20%

LRR –

level 3

Alt 

1a

LRR –

level 4

Alt 

1a

LRR –

level 1

Alt 3 70% 70% 70% 60% 60% 60% 50% 50% 50% 20%

LRR –

level 2

Alt 3 20% 20% 20% 25% 25% 25% 30% 30% 30% 50%

LRR –

level 3

Alt 3 10% 10% 10% 15% 15% 15% 25%

LRR –

level 4

Alt 3

LRR –

level 1

TCp $0 $0 $0 -$4 -$4 -$4 -$8 -$8 -$8 -$19

LRR –

level 2

TCp $0 $0 $0 $2 $2 $2 $4 $4 $4 $12

LRR – TCp $0 $0 $0 $5 $5 $5 $8 $7 $7 $11
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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level 3

LRR –

level 4

TCp $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

Notes: TC=total cost; TCp=total cost applied to the package; alt=alternative; empty cells for adoption rates denote 

0% adoption

2.12.8.9 Lower RR drive tires, Class 7 Day cab low roof tractors

Table 2-195 Costs for Lower Rolling Resistance Drive Tires

Class 7 Day Cab Low Roof Tractors

(2012$/vehicle @ 4 tires/vehicle)

ITEM 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

LRR –

level 1

TC $92 $91 $89 $88 $86 $82 $80 $79 $78 $78

LRR –

level 2

TC $92 $91 $89 $88 $86 $82 $80 $79 $78 $78

LRR –

level 3

TC $113 $110 $108 $105 $104 $102 $100 $99 $91 $89

LRR –

level 4

TC $122 $119 $116 $113 $110 $108 $105 $104 $102 $100

LRR –

level 1

Alt 

1a

50% 50% 50% 50% 50% 50% 50% 50% 50% 50%

LRR –

level 2

Alt 

1a

10% 10% 10% 10% 10% 10% 10% 10% 10% 10%

LRR –

level 3

Alt 

1a

LRR –

level 4

Alt 

1a

LRR –

level 1

Alt 3 50% 50% 50% 60% 60% 60% 50% 50% 50% 20%

LRR –

level 2

Alt 3 10% 10% 10% 25% 25% 25% 30% 30% 30% 50%

LRR –

level 3

Alt 3 10% 10% 10% 15% 15% 15% 25%

LRR –

level 4

Alt 3

LRR –

level 1

TCp $0 $0 $0 $9 $9 $8 $0 $0 $0 -$23

LRR –

level 2

TCp $0 $0 $0 $13 $13 $12 $16 $16 $16 $31

LRR –

level 3

TCp $0 $0 $0 $11 $10 $10 $15 $15 $14 $22

LRR –

level 4

TCp $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

Notes: TC=total cost; TCp=total cost applied to the package; alt=alternative; empty cells for adoption rates denote 

0% adoption
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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2.12.8.10 Lower RR drive tires, Class 8 Day cab low roof tractors

Table 2-196 Costs for Lower Rolling Resistance Drive Tires

Class 8 Day Cab Low Roof Tractors

(2012$/vehicle @ 8 tires/vehicle)

ITEM 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

LRR –

level 1

TC $185 $182 $178 $175 $173 $163 $160 $158 $156 $155

LRR –

level 2

TC $185 $182 $178 $175 $173 $163 $160 $158 $156 $155

LRR –

level 3

TC $226 $221 $216 $210 $207 $204 $201 $198 $182 $179

LRR –

level 4

TC $244 $238 $232 $226 $221 $216 $210 $207 $204 $201

LRR –

level 1

Alt 

1a

50% 50% 50% 50% 50% 50% 50% 50% 50% 50%

LRR –

level 2

Alt 

1a

10% 10% 10% 10% 10% 10% 10% 10% 10% 10%

LRR –

level 3

Alt 

1a

LRR –

level 4

Alt 

1a

LRR –

level 1

Alt 3 50% 50% 50% 60% 60% 60% 50% 50% 50% 20%

LRR –

level 2

Alt 3 10% 10% 10% 25% 25% 25% 30% 30% 30% 50%

LRR –

level 3

Alt 3 10% 10% 10% 15% 15% 15% 25%

LRR –

level 4

Alt 3

LRR –

level 1

TCp $0 $0 $0 $18 $17 $16 $0 $0 $0 -$47

LRR –

level 2

TCp $0 $0 $0 $26 $26 $24 $32 $32 $31 $62

LRR –

level 3

TCp $0 $0 $0 $21 $21 $20 $30 $30 $27 $45

LRR –

level 4

TCp $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

Notes: TC=total cost; TCp=total cost applied to the package; alt=alternative; empty cells for adoption rates denote 

0% adoption
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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2.12.8.11 Lower RR drive tires, Class 7 Day cab high roof tractors

Table 2-197 Costs for Lower Rolling Resistance Drive Tires

Class 7 Day Cab High Roof Tractors

(2012$/vehicle @ 4 tires/vehicle)

ITEM 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

LRR –

level 1

TC $92 $91 $89 $88 $86 $82 $80 $79 $78 $78

LRR –

level 2

TC $92 $91 $89 $88 $86 $82 $80 $79 $78 $78

LRR –

level 3

TC $113 $110 $108 $105 $104 $102 $100 $99 $91 $89

LRR –

level 4

TC $122 $119 $116 $113 $110 $108 $105 $104 $102 $100

LRR –

level 1

Alt 

1a

70% 70% 70% 70% 70% 70% 70% 70% 70% 70%

LRR –

level 2

Alt 

1a

20% 20% 20% 20% 20% 20% 20% 20% 20% 20%

LRR –

level 3

Alt 

1a

LRR –

level 4

Alt 

1a

LRR –

level 1

Alt 3 70% 70% 70% 60% 60% 60% 50% 50% 50% 20%

LRR –

level 2

Alt 3 20% 20% 20% 25% 25% 25% 30% 30% 30% 50%

LRR –

level 3

Alt 3 10% 10% 10% 15% 15% 15% 25%

LRR –

level 4

Alt 3

LRR –

level 1

TCp $0 $0 $0 -$9 -$9 -$8 -$16 -$16 -$16 -$39

LRR –

level 2

TCp $0 $0 $0 $4 $4 $4 $8 $8 $8 $23

LRR –

level 3

TCp $0 $0 $0 $11 $10 $10 $15 $15 $14 $22

LRR –

level 4

TCp $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

Notes: TC=total cost; TCp=total cost applied to the package; alt=alternative; empty cells for adoption rates denote 

0% adoption
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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2.12.8.12 Lower RR drive tires, Class 8 Day cab high roof tractors

Table 2-198 Costs for Lower Rolling Resistance Drive Tires

Class 8 Day Cab High Roof Tractors

(2012$/vehicle @ 8 tires/vehicle)

ITEM 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

LRR –

level 1

TC $185 $182 $178 $175 $173 $163 $160 $158 $156 $155

LRR –

level 2

TC $185 $182 $178 $175 $173 $163 $160 $158 $156 $155

LRR –

level 3

TC $226 $221 $216 $210 $207 $204 $201 $198 $182 $179

LRR –

level 4

TC $244 $238 $232 $226 $221 $216 $210 $207 $204 $201

LRR –

level 1

Alt 

1a

70% 70% 70% 70% 70% 70% 70% 70% 70% 70%

LRR –

level 2

Alt 

1a

20% 20% 20% 20% 20% 20% 20% 20% 20% 20%

LRR –

level 3

Alt 

1a

LRR –

level 4

Alt 

1a

LRR –

level 1

Alt 3 70% 70% 70% 60% 60% 60% 50% 50% 50% 20%

LRR –

level 2

Alt 3 20% 20% 20% 25% 25% 25% 30% 30% 30% 50%

LRR –

level 3

Alt 3 10% 10% 10% 15% 15% 15% 25%

LRR –

level 4

Alt 3

LRR –

level 1

TCp $0 $0 $0 -$18 -$17 -$16 -$32 -$32 -$31 -$78

LRR –

level 2

TCp $0 $0 $0 $9 $9 $8 $16 $16 $16 $47

LRR –

level 3

TCp $0 $0 $0 $21 $21 $20 $30 $30 $27 $45

LRR –

level 4

TCp $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

Notes: TC=total cost; TCp=total cost applied to the package; alt=alternative; empty cells for adoption rates denote 

0% adoption
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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2.12.8.13 Lower RR drive tires, Class 8 Sleeper cab low/mid roof tractors

Table 2-199 Costs for Lower Rolling Resistance Drive Tires

Class 8 Sleeper Cab Low/Mid Roof Tractors

(2012$/vehicle @ 8 tires/vehicle)

ITEM 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

LRR –

level 1

TC $185 $182 $178 $175 $173 $163 $160 $158 $156 $155

LRR –

level 2

TC $185 $182 $178 $175 $173 $163 $160 $158 $156 $155

LRR –

level 3

TC $226 $221 $216 $210 $207 $204 $201 $198 $182 $179

LRR –

level 4

TC $244 $238 $232 $226 $221 $216 $210 $207 $204 $201

LRR –

level 1

Alt 

1a

60% 60% 60% 60% 60% 60% 60% 60% 60% 60%

LRR –

level 2

Alt 

1a

10% 10% 10% 10% 10% 10% 10% 10% 10% 10%

LRR –

level 3

Alt 

1a

LRR –

level 4

Alt 

1a

LRR –

level 1

Alt 3 60% 60% 60% 60% 60% 60% 50% 50% 50% 20%

LRR –

level 2

Alt 3 10% 10% 10% 25% 25% 25% 30% 30% 30% 50%

LRR –

level 3

Alt 3 10% 10% 10% 15% 15% 15% 25%

LRR –

level 4

Alt 3

LRR –

level 1

TCp $0 $0 $0 $0 $0 $0 -$16 -$16 -$16 -$62

LRR –

level 2

TCp $0 $0 $0 $26 $26 $24 $32 $32 $31 $62

LRR –

level 3

TCp $0 $0 $0 $21 $21 $20 $30 $30 $27 $45

LRR –

level 4

TCp $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

Notes: TC=total cost; TCp=total cost applied to the package; alt=alternative; empty cells for adoption rates denote 

0% adoption
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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2.12.8.14 Lower RR drive tires, Class 8 Sleeper cab high roof tractors

Table 2-200 Costs for Lower Rolling Resistance Drive Tires

Class 8 Sleeper Cab High Roof Tractors

(2012$/vehicle @ 8 tires/vehicle)

ITEM 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

LRR –

level 1

TC $185 $182 $178 $175 $173 $163 $160 $158 $156 $155

LRR –

level 2

TC $185 $182 $178 $175 $173 $163 $160 $158 $156 $155

LRR –

level 3

TC $226 $221 $216 $210 $207 $204 $201 $198 $182 $179

LRR –

level 4

TC $244 $238 $232 $226 $221 $216 $210 $207 $204 $201

LRR –

level 1

Alt 

1a

70% 70% 70% 70% 70% 70% 70% 70% 70% 70%

LRR –

level 2

Alt 

1a

20% 20% 20% 20% 20% 20% 20% 20% 20% 20%

LRR –

level 3

Alt 

1a

LRR –

level 4

Alt 

1a

LRR –

level 1

Alt 3 70% 70% 70% 60% 60% 60% 50% 50% 50% 20%

LRR –

level 2

Alt 3 20% 20% 20% 25% 25% 25% 30% 30% 30% 50%

LRR –

level 3

Alt 3 10% 10% 10% 15% 15% 15% 25%

LRR –

level 4

Alt 3

LRR –

level 1

TCp $0 $0 $0 -$18 -$17 -$16 -$32 -$32 -$31 -$78

LRR –

level 2

TCp $0 $0 $0 $9 $9 $8 $16 $16 $16 $47

LRR –

level 3

TCp $0 $0 $0 $21 $21 $20 $30 $30 $27 $45

LRR –

level 4

TCp $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

Notes: TC=total cost; TCp=total cost applied to the package; alt=alternative; empty cells for adoption rates denote 

0% adoption
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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2.12.8.15 Lower RR tires, 53-foot dry van & reefer

Table 2-201 Costs for Lower Rolling Resistance Tires

53-foot Dry Van & Reefer Highway Trailers

(2012$/trailer @ 8 tires/trailer)

ITEM 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

LRR–level 1 TC $185 $182 $178 $175 $173 $163 $160 $158 $156 $155

LRR–level 2 TC $185 $182 $178 $175 $173 $163 $160 $158 $156 $155

LRR–level 1 Alt 1a 50% 51% 52% 53% 54% 56% 57% 58% 59% 60%

LRR–level 2 Alt 1a

LRR–level 1 Alt 3 85% 85% 85% 90% 90% 90%

LRR–level 2 Alt 3 95% 95% 95% 95%

LRR–level 1 TCp $65 $62 $59 $65 $62 $56 -$91 -$91 -$92 -$93

LRR–level 2 TCp $0 $0 $0 $0 $0 $0 $152 $150 $149 $147

Notes: TC=total cost; TCp=total cost applied to the package; alt=alternative; empty cells for adoption rates denote 

0% adoption

2.12.8.16 Lower RR tires, 28-foot dry van

Table 2-202 Costs for Lower Rolling Resistance Tires

28-foot Dry Van Trailers

(2012$/trailer @ 4 tires/trailer)

ITEM 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

LRR–level 1 TC $92 $91 $89 $88 $86 $82 $80 $79 $78 $78

LRR–level 2 TC $92 $91 $89 $88 $86 $82 $80 $79 $78 $78

LRR–level 1 Alt 1a

LRR–level 2 Alt 1a

LRR–level 1 Alt 3 85% 85% 85% 90% 90% 90%

LRR–level 2 Alt 3 95% 95% 95% 95%

LRR–level 1 TCp $78 $77 $76 $79 $78 $73 $0 $0 $0 $0

LRR–level 2 TCp $0 $0 $0 $0 $0 $0 $76 $75 $74 $74

Notes: TC=total cost; TCp=total cost applied to the package; alt=alternative; empty cells for adoption rates denote 

0% adoption

2.12.8.17 Lower RR tires, Non-box highway trailers

Table 2-203 Costs for Lower Rolling Resistance Tires

Other Non-Box Highway Trailers

(2012$/trailer @ 4 tires/trailer)

ITEM 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

LRR–level 1 TC $185 $182 $178 $175 $173 $163 $160 $158 $156 $155

LRR–level 2 TC $185 $182 $178 $175 $173 $163 $160 $158 $156 $155

LRR–level 1 Alt 1a

LRR–level 2 Alt 1a

LRR–level 1 Alt 3 100% 100% 100% 100% 100% 100%

LRR–level 2 Alt 3 100% 100% 100% 100%

LRR–level 1 TCp $185 $182 $178 $175 $173 $163 $0 $0 $0 $0

LRR–level 2 TCp $0 $0 $0 $0 $0 $0 $160 $158 $156 $155

Notes: TC=total cost; TCp=total cost applied to the package; alt=alternative; empty cells for adoption rates denote 

0% adoption
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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2.12.8.18 Lower RR tires, HD pickup & van ($/tire)

We have estimated the costs of lower rolling resistance tires for HD pickups and vans 

using the costs used in the 2017-2025 light-duty FRM. In that rule, we estimated the costs of 

lower rolling resistance tires level 1 at $5/vehicle including a spare (DMC, 2010$, in all years) 

and level 2 at $40/vehicle assuming no spare (DMC, 2010$, in 2021). For HD pickups and vans, 

we have scaled upward both of those costs by 50 percent to account for the heavier and larger 

HD tires. We consider the level 1 tires to be learned out (curve 1) and the level 2 tires to be on 

the steep portion of the curve until 2021 after which it is on the flatter portion of the curve (curve 

11). We have applied a low complexity markup to both with short term markups through 2018 

for level 1 and through 2024 for level 2. With the exception of the 50 percent scaling factor, all 

LRR tire costs for HD pickups and vans are identical to the 2017-2025 light-duty FRM. The 

resultant costs are presented in Table 2-204. 

Table 2-204 Costs for Lower Rolling Resistance Tires

HD Pickups & Vans 

(2012$ @ 4 tires/vehicle)

ITEM 2021 2022 2023 2024 2025 2026 2027

LRR – level 1 DMC $8 $8 $8 $8 $8 $8 $8

LRR – level 2 DMC $63 $61 $59 $58 $56 $54 $53

LRR – level 1 IC $2 $2 $2 $2 $2 $2 $2

LRR – level 2 IC $15 $15 $15 $15 $12 $12 $12

LRR – level 1 TC $10 $10 $10 $10 $10 $10 $10

LRR – level 2 TC $78 $76 $74 $73 $68 $66 $65

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost

2.12.8.19 Automatic Tire Inflation Systems (ATIS)

For tractors, we have estimated the cost of this technology based on an estimate from 

TetraTech of $1143 (retail, 2013$). Using that estimate we divided by a 1.36 RPE and converted 

to 2012$ to arrive at a cost of $828 (DMC, 2012$, in 2018). We consider this technology to be 

on the flat portion of the learning curve (curve 12) and have applied a low complexity ICM with 

short term markups through 2022. The resultant technology costs, adoption rates and total cost 

applied to the package are shown in Table 2-205 for tractors.

Table 2-205 Costs for Automatic Tire Inflation Systems

Tractors (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

ATIS DMC $828 $803 $779 $755 $740 $725 $711 $697 $683 $669

ATIS IC $148 $147 $147 $147 $147 $115 $115 $115 $115 $115

ATIS TC $975 $950 $926 $902 $887 $841 $826 $812 $798 $784

ATIS Alt 1a

ATIS Alt 3 20% 20% 20% 40% 40% 40% 40%

ATIS TCp $0 $0 $0 $180 $177 $168 $330 $325 $319 $314

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the 

package; alt=alternative; empty cells for adoption rates denote 0% adoption
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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For trailers, we have estimated the cost of this technology based on an estimate from 

TetraTech of $800 (retail, 2013$). We consider this estimate to be valid for all trailers except 

tandems. For tandems, we have used an estimate of $600 (retail, 2013$) since they have just one 

axle. Using these estimates we divided by a 1.36 RPE and converted to 2012$ to arrive at a cost 

of $579 (DMC, 2012$, in 2018) for all but tandems and $435 (DMC, 2012$, in 2018) for 

tandems. We consider this technology to be on the flat portion of the learning curve (curve 12) 

and have applied a low complexity ICM with short term markups through 2022. The resultant 

technology costs, adoption rates and total cost applied to the package are shown in Table 2-206

for 53-foot dry and reefer vans, in Table 2-207 for 28-foot dry vans and in Table 2-208 for nonbox highway trailers.

Table 2-206 Costs for Automatic Tire Inflation Systems

53-foot Dry and Reefer Van Trailers (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

ATIS DMC $579 $562 $545 $529 $518 $508 $498 $488 $478 $469

ATIS IC $103 $103 $103 $103 $103 $81 $81 $81 $81 $80

ATIS TC $683 $665 $648 $632 $621 $589 $578 $568 $559 $549

ATIS Alt 1a 50% 51% 52% 53% 54% 56% 57% 58% 59% 60%

ATIS Alt 3 85% 85% 85% 90% 90% 90% 95% 95% 95% 95%

ATIS TCp $239 $226 $214 $234 $224 $200 $220 $210 $201 $192

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the 

package; alt=alternative

Table 2-207 Costs for Automatic Tire Inflation Systems

28-foot Dry Van Trailers (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

ATIS DMC $435 $422 $409 $397 $389 $381 $373 $366 $359 $351

ATIS IC $78 $77 $77 $77 $77 $61 $60 $60 $60 $60

ATIS TC $512 $499 $486 $474 $466 $441 $434 $426 $419 $412

ATIS Alt 1a

ATIS Alt 3 85% 85% 85% 90% 90% 90% 95% 95% 95% 95%

ATIS TCp $435 $424 $413 $426 $419 $397 $412 $405 $398 $391

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the 

package; alt=alternative; empty cells for adoption rates denote 0% adoption

Table 2-208 Costs for Automatic Tire Inflation Systems

Non-box Highway Trailers (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

ATIS DMC $579 $562 $545 $529 $518 $508 $498 $488 $478 $469

ATIS IC $103 $103 $103 $103 $103 $81 $81 $81 $81 $80

ATIS TC $683 $665 $648 $632 $621 $589 $578 $568 $559 $549

ATIS Alt 1a

ATIS Alt 3 100% 100% 100% 100% 100% 100% 100% 100% 100% 100%

ATIS TCp $683 $665 $648 $632 $621 $589 $578 $568 $559 $549

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the 

package; alt=alternative; empty cells for adoption rates denote 0% adoption
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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2.12.9 Aerodynamic Improvements (aero)

The agencies’ estimates for cost of tractor aero features are based the work done by ICF 

in support of the Phase 1 HD rules. For trailers, we have based our estimates on the work 

presented in the ICCT trailer technology report.177

2.12.9.1 Aero improvements, Day cab low roof tractors

For low roof day cab tractors, Aero Bin 2 costs are estimated at $1001, Bin 3 at $2022 

and Bin 4 at $2578 (all are DMC, in 2012$, and applicable in 2014). We consider Bin 2 

technologies to be beyond the effects of learning (curve 1), Bin 3 technologies to be on the flat 

portion of the curve (curve 2) and Bin 4 technologies to be on the steep portion of the curve 

(curve 4). We have applied a low complexity ICMs to each with short term markups through 

2022. The resultant technology costs, adoption rates and total cost applied to the package are 

shown in Table 2-209.

Table 2-209 Costs of Aero Technologies

Day Cab Low Roof Tractors (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Aero Bin2 DMC $1,001 $1,001 $1,001 $1,001 $1,001 $1,001 $1,001 $1,001 $1,001 $1,001

Aero Bin3 DMC $1,790 $1,755 $1,719 $1,685 $1,651 $1,618 $1,586 $1,554 $1,539 $1,523

Aero Bin4 DMC $1,650 $1,601 $1,553 $1,506 $1,461 $1,417 $1,375 $1,333 $1,307 $1,281

Aero Bin2 IC $179 $179 $179 $179 $179 $140 $140 $140 $140 $140

Aero Bin3 IC $358 $357 $357 $356 $356 $281 $281 $280 $280 $280

Aero Bin4 IC $448 $447 $447 $446 $445 $354 $354 $353 $353 $353

Aero Bin2 TC $1,180 $1,180 $1,180 $1,180 $1,180 $1,141 $1,141 $1,141 $1,141 $1,141

Aero Bin3 TC $2,148 $2,112 $2,076 $2,041 $2,007 $1,899 $1,867 $1,835 $1,819 $1,803

Aero Bin4 TC $2,098 $2,048 $1,999 $1,952 $1,906 $1,771 $1,728 $1,687 $1,660 $1,634

Aero Bin2 Alt 

1a

60% 60% 60% 60% 60% 60% 60% 60% 60% 60%

Aero Bin3 Alt 

1a

Aero Bin4 Alt 

1a

Aero Bin2 Alt 3 60% 60% 60% 75% 75% 75% 60% 60% 60% 50%

Aero Bin3 Alt 3 25% 25% 25% 38% 38% 38% 40%

Aero Bin4 Alt 3 2% 2% 2% 10%

Aero Bin2 TCp $0 $0 $0 $177 $177 $171 $0 $0 $0 -$114

Aero Bin3 TCp $0 $0 $0 $510 $502 $475 $709 $697 $691 $721

Aero Bin4 TCp $0 $0 $0 $0 $0 $0 $35 $34 $33 $163

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

2.12.9.2 Aero improvements, Day cab high roof tractors

For high roof day cab tractors, Aero Bin 3 costs are estimated at $1028, Bin 4 at $2049, 

Bin 5 at $2612, Bin 6 at $3176 and Bin 7 at $3739 (all are DMC, in 2012$, and applicable in 

2014). We consider Bin 3 technologies to be on the flat portion of the curve (curve 2) and Bin 4 

through 7 technologies to be on the steep portion of the curve (curve 4). We have applied a low 
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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complexity ICMs to Bins 3 and 4 with short term markups through 2022. We have applied 

medium complexity ICMs to Bins 5 through 7 with short term markups through 2025. The 

resultant technology costs, adoption rates and total cost applied to the package are shown in 

Table 2-210.

Table 2-210 Costs of Aero Technologies

Day Cab High Roof Tractors (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Aero Bin3 DMC $910 $892 $874 $856 $839 $822 $806 $790 $782 $774

Aero Bin4 DMC $1,311 $1,272 $1,234 $1,197 $1,161 $1,126 $1,092 $1,059 $1,038 $1,017

Aero Bin5 DMC $1,672 $1,622 $1,573 $1,526 $1,480 $1,436 $1,393 $1,351 $1,324 $1,297

Aero Bin6 DMC $2,032 $1,971 $1,912 $1,855 $1,799 $1,745 $1,693 $1,642 $1,609 $1,577

Aero Bin7 DMC $2,393 $2,321 $2,252 $2,184 $2,118 $2,055 $1,993 $1,933 $1,895 $1,857

Aero Bin3 IC $182 $182 $181 $181 $181 $143 $143 $142 $142 $142

Aero Bin4 IC $356 $355 $355 $354 $354 $281 $281 $281 $281 $281

Aero Bin5 IC $742 $740 $737 $735 $732 $730 $728 $726 $544 $543

Aero Bin6 IC $902 $899 $896 $893 $890 $888 $885 $882 $661 $660

Aero Bin7 IC $1,062 $1,059 $1,055 $1,052 $1,048 $1,045 $1,042 $1,039 $779 $777

Aero Bin3 TC $1,092 $1,073 $1,055 $1,037 $1,020 $965 $949 $932 $924 $916

Aero Bin4 TC $1,667 $1,627 $1,589 $1,551 $1,515 $1,407 $1,373 $1,340 $1,319 $1,298

Aero Bin5 TC $2,414 $2,361 $2,310 $2,260 $2,212 $2,166 $2,120 $2,077 $1,868 $1,840

Aero Bin6 TC $2,934 $2,870 $2,808 $2,748 $2,690 $2,633 $2,578 $2,524 $2,271 $2,237

Aero Bin7 TC $3,455 $3,380 $3,307 $3,236 $3,167 $3,100 $3,035 $2,972 $2,674 $2,634

Aero Bin3 Alt 

1a

70% 70% 70% 70% 70% 70% 70% 70% 70% 70%

Aero Bin4 Alt 

1a

20% 20% 20% 20% 20% 20% 20% 20% 20% 20%

Aero Bin5 Alt 

1a

Aero Bin6 Alt 

1a

Aero Bin7 Alt 

1a

Aero Bin3 Alt 3 70% 70% 70% 40% 40% 40% 30% 30% 30% 20%

Aero Bin4 Alt 3 20% 20% 20% 35% 35% 35% 30% 30% 30% 20%

Aero Bin5 Alt 3 20% 20% 20% 25% 25% 25% 35%

Aero Bin6 Alt 3 5% 5% 5% 13% 13% 13% 20%

Aero Bin7 Alt 3 2% 2% 2% 5%

Aero Bin3 TCp $0 $0 $0 -$311 -$306 -$290 -$379 -$373 -$370 -$458

Aero Bin4 TCp $0 $0 $0 $233 $227 $211 $137 $134 $132 $0

Aero Bin5 TCp $0 $0 $0 $452 $442 $433 $530 $519 $467 $644

Aero Bin6 TCp $0 $0 $0 $137 $134 $132 $335 $328 $295 $447

Aero Bin7 TCp $0 $0 $0 $0 $0 $0 $61 $59 $53 $132

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

2.12.9.3 Aero improvements, Sleeper cab low/mid roof tractors

For low and mid roof sleeper cab tractors, Aero Bin 2 costs are estimated at $1222, Bin 3 

at $2313 and Bin 4 at $2949 (all are DMC, in 2012$, and applicable in 2014). We consider Bin 

2 technologies to be beyond the effects of learning (curve 1), Bin 3 technologies to be on the flat 
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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portion of the curve (curve 2) and Bin 4 technologies to be on the steep portion of the curve 

(curve 4). We have applied a low complexity ICMs to each with short term markups through 

2022. The resultant technology costs, adoption rates and total cost applied to the package are 

shown in Table 2-211.

Table 2-211 Costs of Aero Technologies

Sleeper Cab Low/Mid Roof Tractors (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Aero Bin2 DMC $1,222 $1,222 $1,222 $1,222 $1,222 $1,222 $1,222 $1,222 $1,222 $1,222

Aero Bin3 DMC $2,048 $2,007 $1,967 $1,928 $1,889 $1,851 $1,814 $1,778 $1,760 $1,742

Aero Bin4 DMC $1,888 $1,831 $1,776 $1,723 $1,671 $1,621 $1,572 $1,525 $1,495 $1,465

Aero Bin2 IC $218 $218 $218 $218 $218 $171 $171 $171 $171 $171

Aero Bin3 IC $409 $409 $408 $408 $407 $321 $321 $321 $321 $320

Aero Bin4 IC $512 $512 $511 $510 $509 $405 $405 $404 $404 $404

Aero Bin2 TC $1,440 $1,440 $1,440 $1,440 $1,440 $1,393 $1,393 $1,393 $1,393 $1,393

Aero Bin3 TC $2,457 $2,416 $2,375 $2,335 $2,296 $2,172 $2,135 $2,099 $2,081 $2,063

Aero Bin4 TC $2,400 $2,343 $2,287 $2,233 $2,181 $2,026 $1,977 $1,930 $1,899 $1,869

Aero Bin2 Alt 

1a

70% 70% 70% 70% 70% 70% 70% 70% 70% 70%

Aero Bin3 Alt 

1a

Aero Bin4 Alt 

1a

Aero Bin2 Alt 3 70% 70% 70% 75% 75% 75% 60% 60% 60% 50%

Aero Bin3 Alt 3 25% 25% 25% 38% 38% 38% 40%

Aero Bin4 Alt 3 2% 2% 2% 10%

Aero Bin2 TCp $0 $0 $0 $72 $72 $70 -$139 -$139 -$139 -$279

Aero Bin3 TCp $0 $0 $0 $584 $574 $543 $811 $797 $791 $825

Aero Bin4 TCp $0 $0 $0 $0 $0 $0 $40 $39 $38 $187

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

2.12.9.4 Aero improvements, Sleeper cab high roof tractors

For high roof sleeper cab tractors, Aero Bin 3 costs are estimated at $1387, Bin 4 at 

$2379, Bin 5 at $3034, Bin 6 at $3688 and Bin 7 at $4342 (all are DMC, in 2012$, and 

applicable in 2014). We consider Bin 3 technologies to be on the flat portion of the curve (curve 

2) and Bin 4 through 7 technologies to be on the steep portion of the curve (curve 4). We have 

applied a low complexity ICMs to Bins 3 and 4 with short term markups through 2022. We have 

applied medium complexity ICMs to Bins 5 through 7 with short term markups through 2025. 

The resultant technology costs, adoption rates and total cost applied to the package are shown in 

Table 2-212.
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Table 2-212 Costs of Aero Technologies

Sleeper Cab High Roof Tractors (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Aero Bin3 DMC $1,228 $1,204 $1,180 $1,156 $1,133 $1,110 $1,088 $1,066 $1,056 $1,045

Aero Bin4 DMC $1,523 $1,477 $1,433 $1,390 $1,348 $1,308 $1,268 $1,230 $1,206 $1,182

Aero Bin5 DMC $1,942 $1,883 $1,827 $1,772 $1,719 $1,667 $1,617 $1,569 $1,537 $1,507

Aero Bin6 DMC $2,360 $2,290 $2,221 $2,154 $2,090 $2,027 $1,966 $1,907 $1,869 $1,832

Aero Bin7 DMC $2,779 $2,696 $2,615 $2,536 $2,460 $2,387 $2,315 $2,246 $2,201 $2,157

Aero Bin3 IC $245 $245 $245 $245 $244 $193 $192 $192 $192 $192

Aero Bin4 IC $413 $413 $412 $412 $411 $327 $326 $326 $326 $326

Aero Bin5 IC $862 $859 $856 $853 $851 $848 $845 $843 $632 $631

Aero Bin6 IC $1,048 $1,044 $1,041 $1,037 $1,034 $1,031 $1,028 $1,025 $768 $767

Aero Bin7 IC $1,234 $1,229 $1,225 $1,221 $1,217 $1,214 $1,210 $1,207 $904 $903

Aero Bin3 TC $1,474 $1,449 $1,425 $1,401 $1,377 $1,303 $1,281 $1,259 $1,248 $1,237

Aero Bin4 TC $1,936 $1,890 $1,845 $1,801 $1,759 $1,634 $1,595 $1,557 $1,532 $1,508

Aero Bin5 TC $2,803 $2,742 $2,683 $2,625 $2,569 $2,515 $2,463 $2,412 $2,169 $2,137

Aero Bin6 TC $3,408 $3,334 $3,262 $3,192 $3,124 $3,058 $2,994 $2,932 $2,637 $2,598

Aero Bin7 TC $4,013 $3,925 $3,840 $3,758 $3,678 $3,600 $3,525 $3,452 $3,105 $3,060

Aero Bin3 Alt 

1a

70% 70% 70% 70% 70% 70% 70% 70% 70% 70%

Aero Bin4 Alt 

1a

20% 20% 20% 20% 20% 20% 20% 20% 20% 20%

Aero Bin5 Alt 

1a

Aero Bin6 Alt 

1a

Aero Bin7 Alt 

1a

Aero Bin3 Alt 3 70% 70% 70% 40% 40% 40% 30% 30% 30% 20%

Aero Bin4 Alt 3 20% 20% 20% 35% 35% 35% 30% 30% 30% 20%

Aero Bin5 Alt 3 20% 20% 20% 25% 25% 25% 35%

Aero Bin6 Alt 3 5% 5% 5% 13% 13% 13% 20%

Aero Bin7 Alt 3 2% 2% 2% 5%

Aero Bin3 TCp $0 $0 $0 -$420 -$413 -$391 -$512 -$503 -$499 -$619

Aero Bin4 TCp $0 $0 $0 $270 $264 $245 $159 $156 $153 $0

Aero Bin5 TCp $0 $0 $0 $525 $514 $503 $616 $603 $542 $748

Aero Bin6 TCp $0 $0 $0 $160 $156 $153 $389 $381 $343 $520

Aero Bin7 TCp $0 $0 $0 $0 $0 $0 $71 $69 $62 $153

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

2.12.9.5 Aero improvements, trailers

For dry and reefer van trailers, Aero Bin 3 costs are based on and ICCT estimate of $700 

(retail, 2013$), Bin 4 costs are based on an ICCT estimate of $1000 (retail, 2013$), Bin 5 costs 

are based on an ICCT estimate of $1600 (retail, 2013$), Bin 6 costs are based on an ICCT 

estimate of $1900 (retail, 2013$), and Bin 7 costs are based on an ICCT estimate of $2200 

(retail, 2013$). We have used these costs and divided by a 1.36 RPE and converted to 2012$ to 

arrive at direct manufacturing costs of $507, $724, $1159, $1376 and $1594 for Bins 3 through 

7, respectively (all are DMC, in 2012$, applicable in 2014). We consider each of these 

technologies to be on the flat portion of the learning curve (curve 2) and have applied low 
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complexity ICMs with short term markups through 2018. The resultant technology costs, 

adoption rates and total cost applied to the package are shown in Table 2-213 and Table 2-214

for 53-foot dry and reefer van trailers, respectively, and in Table 2-215 for 28-foot dry van 

trailers.

Table 2-213 Costs of Aero Technologies

53-foot Dry Van Trailers (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Aero Bin3 DMC $449 $440 $431 $422 $414 $406 $398 $390 $386 $382

Aero Bin4 DMC $641 $628 $616 $604 $591 $580 $568 $557 $551 $546

Aero Bin5 DMC $1,026 $1,006 $985 $966 $946 $927 $909 $891 $882 $873

Aero Bin6 DMC $1,218 $1,194 $1,170 $1,147 $1,124 $1,101 $1,079 $1,058 $1,047 $1,037

Aero Bin7 DMC $1,411 $1,383 $1,355 $1,328 $1,301 $1,275 $1,250 $1,225 $1,212 $1,200

Aero Bin8 DMC $1,860 $1,822 $1,786 $1,750 $1,715 $1,681 $1,647 $1,614 $1,598 $1,582

Aero Bin3 IC $90 $71 $71 $71 $70 $70 $70 $70 $70 $70

Aero Bin4 IC $128 $101 $101 $101 $101 $101 $100 $100 $100 $100

Aero Bin5 IC $205 $161 $161 $161 $161 $161 $161 $161 $161 $161

Aero Bin6 IC $244 $192 $191 $191 $191 $191 $191 $191 $191 $191

Aero Bin7 IC $282 $222 $222 $222 $221 $221 $221 $221 $221 $221

Aero Bin8 IC $372 $293 $292 $292 $292 $292 $291 $291 $291 $291

Aero Bin3 TC $539 $511 $502 $493 $484 $476 $468 $460 $456 $452

Aero Bin4 TC $769 $729 $717 $704 $692 $680 $669 $657 $652 $646

Aero Bin5 TC $1,231 $1,167 $1,147 $1,127 $1,107 $1,088 $1,070 $1,051 $1,042 $1,034

Aero Bin6 TC $1,462 $1,386 $1,362 $1,338 $1,315 $1,292 $1,270 $1,249 $1,238 $1,227

Aero Bin7 TC $1,693 $1,604 $1,577 $1,549 $1,523 $1,496 $1,471 $1,446 $1,433 $1,421

Aero Bin8 TC $2,231 $2,115 $2,078 $2,042 $2,007 $1,973 $1,939 $1,906 $1,889 $1,873

Aero Bin3 Alt 

1a

20% 20% 20% 20% 20% 20% 20% 20% 20% 20%

Aero Bin4 Alt 

1a

30% 31% 32% 33% 34% 36% 37% 38% 39% 40%

Aero Bin5 Alt 

1a

5% 5% 5% 5% 5% 5% 5% 5% 5% 5%

Aero Bin6 Alt 

1a

Aero Bin7 Alt 

1a

Aero Bin8 Alt 

1a

Aero Bin3 Alt 3 30% 30% 30% 5% 5% 5%

Aero Bin4 Alt 3 60% 60% 60% 55% 55% 55% 25% 25% 25%

Aero Bin5 Alt 3 5% 5% 5% 10% 10% 10% 10% 10% 10% 10%

Aero Bin6 Alt 3

Aero Bin7 Alt 3 30% 30% 30% 65% 65% 65% 50%

Aero Bin8 Alt 3 40%

Aero Bin3 TCp $54 $51 $50 -$74 -$73 -$71 -$94 -$92 -$91 -$90

Aero Bin4 TCp $231 $212 $201 $155 $145 $129 -$80 -$85 -$91 -$258

Aero Bin5 TCp $0 $0 $0 $56 $55 $54 $53 $53 $52 $52

Aero Bin6 TCp $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

Aero Bin7 TCp $0 $0 $0 $465 $457 $449 $956 $940 $932 $711

Aero Bin8 TCp $0 $0 $0 $0 $0 $0 $0 $0 $0 $749

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption
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Table 2-214 Costs of Aero Technologies

Reefer Van Trailers (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Aero Bin3 DMC $449 $440 $431 $422 $414 $406 $398 $390 $386 $382

Aero Bin4 DMC $641 $628 $616 $604 $591 $580 $568 $557 $551 $546

Aero Bin5 DMC $1,026 $1,006 $985 $966 $946 $927 $909 $891 $882 $873

Aero Bin6 DMC $1,218 $1,194 $1,170 $1,147 $1,124 $1,101 $1,079 $1,058 $1,047 $1,037

Aero Bin7 DMC $1,411 $1,383 $1,355 $1,328 $1,301 $1,275 $1,250 $1,225 $1,212 $1,200

Aero Bin8 DMC $1,860 $1,822 $1,786 $1,750 $1,715 $1,681 $1,647 $1,614 $1,598 $1,582

Aero Bin3 IC $90 $71 $71 $71 $70 $70 $70 $70 $70 $70

Aero Bin4 IC $128 $101 $101 $101 $101 $101 $100 $100 $100 $100

Aero Bin5 IC $205 $161 $161 $161 $161 $161 $161 $161 $161 $161

Aero Bin6 IC $244 $192 $191 $191 $191 $191 $191 $191 $191 $191

Aero Bin7 IC $282 $222 $222 $222 $221 $221 $221 $221 $221 $221

Aero Bin8 IC $372 $293 $292 $292 $292 $292 $291 $291 $291 $291

Aero Bin3 TC $539 $511 $502 $493 $484 $476 $468 $460 $456 $452

Aero Bin4 TC $769 $729 $717 $704 $692 $680 $669 $657 $652 $646

Aero Bin5 TC $1,231 $1,167 $1,147 $1,127 $1,107 $1,088 $1,070 $1,051 $1,042 $1,034

Aero Bin6 TC $1,462 $1,386 $1,362 $1,338 $1,315 $1,292 $1,270 $1,249 $1,238 $1,227

Aero Bin7 TC $1,693 $1,604 $1,577 $1,549 $1,523 $1,496 $1,471 $1,446 $1,433 $1,421

Aero Bin8 TC $2,231 $2,115 $2,078 $2,042 $2,007 $1,973 $1,939 $1,906 $1,889 $1,873

Aero Bin3 Alt 

1a

20% 20% 20% 20% 20% 20% 20% 20% 20% 20%

Aero Bin4 Alt 

1a

30% 31% 32% 33% 34% 36% 37% 38% 39% 40%

Aero Bin5 Alt 

1a

5% 5% 5% 5% 5% 5% 5% 5% 5% 5%

Aero Bin6 Alt 

1a

Aero Bin7 Alt 

1a

Aero Bin8 Alt 

1a

Aero Bin3 Alt 3 30% 30% 30% 5% 5% 5%

Aero Bin4 Alt 3 60% 60% 60% 55% 55% 55% 25% 25% 25%

Aero Bin5 Alt 3 5% 5% 5% 10% 10% 10% 10% 10% 10% 20%

Aero Bin6 Alt 3

Aero Bin7 Alt 3 30% 30% 30% 65% 65% 65% 60%

Aero Bin8 Alt 3 20%

Aero Bin3 TCp $54 $51 $50 -$74 -$73 -$71 -$94 -$92 -$91 -$90

Aero Bin4 TCp $231 $212 $201 $155 $145 $129 -$80 -$85 -$91 -$258

Aero Bin5 TCp $0 $0 $0 $56 $55 $54 $53 $53 $52 $155

Aero Bin6 TCp $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

Aero Bin7 TCp $0 $0 $0 $465 $457 $449 $956 $940 $932 $853

Aero Bin8 TCp $0 $0 $0 $0 $0 $0 $0 $0 $0 $375

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption
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Table 2-215 Costs of Aero Technologies

28-foot Dry Van Trailers (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Aero Bin3 DMC $449 $440 $431 $422 $414 $406 $398 $390 $386 $382

Aero Bin4 DMC $641 $628 $616 $604 $591 $580 $568 $557 $551 $546

Aero Bin5 DMC $1,090 $1,068 $1,047 $1,026 $1,006 $985 $966 $946 $937 $928

Aero Bin3 IC $90 $71 $71 $71 $70 $70 $70 $70 $70 $70

Aero Bin4 IC $128 $101 $101 $101 $101 $101 $100 $100 $100 $100

Aero Bin5 IC $218 $171 $171 $171 $171 $171 $171 $171 $171 $171

Aero Bin3 TC $539 $511 $502 $493 $484 $476 $468 $460 $456 $452

Aero Bin4 TC $769 $729 $717 $704 $692 $680 $669 $657 $652 $646

Aero Bin5 TC $1,308 $1,240 $1,218 $1,197 $1,177 $1,156 $1,137 $1,117 $1,108 $1,098

Aero Bin3 Alt 

1a

Aero Bin4 Alt 

1a

Aero Bin5 Alt 

1a

Aero Bin3 Alt 3 95% 95% 95% 70% 70% 70% 30%

Aero Bin4 Alt 3 30% 30% 30% 60%

Aero Bin5 Alt 3 10%

Aero Bin3 TCp $0 $0 $0 $468 $460 $452 $328 $322 $319 $136

Aero Bin4 TCp $0 $0 $0 $0 $0 $0 $281 $276 $274 $543

Aero Bin5 TCp $0 $0 $0 $0 $0 $0 $0 $0 $0 $110

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

2.12.9.6 Aero improvements, HD pickups and vans

For HD pickups and vans, we have based our aero improvement costs on values used in 

our light-duty 2017-2025 final rule. Using those values updated to 2012$ results in costs for 

aero 1 (passive aero treatments) and active aero treatments of $47 and $142 (both are DMC, in 

2012$, in 2015). Note that the aero 2 costs are the passive aero 1 plus the active aero costs. We 

consider both of these technologies to be on the flat portion of the learning curve (curve 8) and, 

to aero 1, have applied low complexity markups with near term markups through 2018 and, to 

active aero, have applied medium complexity markups with near term markups through 2024. 

The resultant costs for HD pickups and vans are shown in Table 2-216 (aero 1) and in Table 

2-217 (active aero) and in Table 2-218 (aero 2, passive+active aero).

Table 2-216 Costs for Passive Aero Treatments – Aero 1

Gasoline & Diesel HD Pickups and Vans (2012$)

ITEM 2021 2022 2023 2024 2025 2026 2027

Aero 1 – passive aero DMC $42 $41 $40 $39 $38 $38 $38

Aero 1 – passive aero IC $9 $9 $9 $9 $9 $9 $9

Aero 1 – passive aero TC $51 $50 $49 $48 $47 $47 $47

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost
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Table 2-217 Costs for Active Aero Treatments

Gasoline & Diesel HD Pickups and Vans (2012$)

ITEM 2021 2022 2023 2024 2025 2026 2027

Aero 2 – active aero DMC $125 $122 $120 $118 $115 $114 $113

Aero 2 – active aero IC $54 $54 $54 $54 $40 $40 $40

Aero 2 – active aero TC $179 $177 $174 $172 $156 $154 $153

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost

Table 2-218 Costs for Aero 2 (passive plus active aero)

Gasoline & Diesel HD Pickups and Vans (2012$)

ITEM 2021 2022 2023 2024 2025 2026 2027

Aero 2 – active aero DMC $166 $163 $160 $157 $154 $152 $151

Aero 2 – active aero IC $63 $63 $63 $63 $50 $49 $49

Aero 2 – active aero TC $230 $227 $223 $220 $203 $201 $200

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost

2.12.10 Other Technologies

2.12.10.1 Advanced cruise controls, tractors

We have estimated the cost of this technology based on an estimate from TetraTech of 

$1100 (retail, 2013$). Using that estimate we divided by a 1.36 RPE and converted to 2012$ to 

arrive at a cost of $797 (DMC, 2012$, in 2018). We consider this technology to be on the flat 

portion of the learning curve (curve 12) and have applied a low complexity ICM with short term 

markups through 2022. The resultant technology costs, adoption rates and total cost applied to 

the package are shown in Table 2-219 for tractors. 

Table 2-219 Costs for Advanced Cruise Controls

Tractors (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Advanced cruise control DMC $797 $773 $750 $727 $713 $698 $684 $671 $657 $644

Advanced cruise control IC $142 $142 $142 $141 $141 $111 $111 $111 $111 $111

Advanced cruise control TC $939 $915 $891 $868 $854 $809 $795 $782 $768 $755

Advanced cruise control Alt 1a

Advanced cruise control Alt 3 20% 20% 20% 40% 40% 40% 40%

Advanced cruise control TCp $0 $0 $0 $174 $171 $162 $318 $313 $307 $302

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

2.12.10.2 Improved accessories

We have estimated the cost of this technology based on an estimate from TetraTech of 

$350 (retail, 2013$). Using that estimate we divided by a 1.36 RPE and converted to 2012$ to 

arrive at a cost of $254 (DMC, 2012$, in 2018). We consider this technology to be on the flat 

portion of the learning curve (curve 12) and have applied a low complexity ICM with short term 

markups through 2022. The resultant technology costs, adoption rates and total cost applied to 

the package are shown in Table 2-220 for tractors.
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Table 2-220 Costs for Improved Accessories

Tractors (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Improved accessories DMC $254 $246 $239 $231 $227 $222 $218 $213 $209 $205

Improved accessories IC $45 $45 $45 $45 $45 $35 $35 $35 $35 $35

Improved accessories TC $299 $291 $284 $276 $272 $258 $253 $249 $244 $240

Improved accessories Alt 1a

Improved accessories Alt 3 10% 10% 10% 20% 20% 20% 30%

Improved accessories TCp $0 $0 $0 $28 $27 $26 $51 $50 $49 $72

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

For HD pickups and vans, we have estimated the costs for two levels of improved 

accessories based on estimates presented in the light-duty 2017-2025 final rule. In that rule, we 

estimated the costs of IACC1 and IACC2 at $73 and $118, respectively (both are DMC, 2009$, 

in 2015). With updates to 2012$, these costs become $77 and $124, respectively (both are DMC, 

2012$, in 2015). Note that IACC2 includes IACC1. We consider these technologies to be on the 

flat portion of the learning curve (curve 8) and have applied low complexity markups with near 

term markups through 2018. The resultant cost for both are shown in Table 2-221.

Table 2-221 Costs for Improved Accessories

Gasoline & Diesel HD Pickups and Vans (2012$)

ITEM 2021 2022 2023 2024 2025 2026 2027

Improved accessories 1 (IACC1) DMC $67 $66 $64 $63 $62 $61 $61

Improved accessories 1 (IACC2) DMC $109 $106 $104 $102 $100 $99 $98

Improved accessories 1 (IACC1) IC $15 $15 $15 $15 $15 $15 $15

Improved accessories 1 (IACC2) IC $24 $24 $24 $24 $24 $24 $24

Improved accessories 1 (IACC1) TC $82 $80 $79 $78 $77 $76 $75

Improved accessories 1 (IACC2) TC $132 $130 $128 $126 $124 $123 $122

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost

2.12.10.3 Weight reduction, vocational vehicles

We have estimated the cost of a 200, 400 and 1000 pound weight reduction on vocational 

vehicles at $4/pound, $6/pound and $8/pound, respectively (all are retail, 2013$). Using those 

costs we have divided by a 1.36 RPE and converted to 2012$ to arrive at costs of $579, $1738 

and $5795 for 200, 400 and 1000 pound reductions, respectively (all are DMC, in 2012$, 

applicable in 2021). We consider each of these weight reduction levels to be on the flat portion 

of the learning curve (curve 13) and have applied low complexity ICMs with short term markups 

through 2022 for 200 and 400 pound reductions, and medium complexity ICMs with short term 

markups through 2022 for a 1000 pound reduction. The resultant technology costs, adoption 

rates and total cost applied to the package are shown in Table 2-222 though Table 2-227.
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Table 2-222 Costs for a 200 Pound Weight Reduction

Vocational Light/Medium/Heavy HD Urban/Multipurpose Vehicles (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Weight reduction, 200 lbs DMC $635 $616 $597 $579 $562 $545 $529 $518 $508 $498

Weight reduction, 200 lbs IC $104 $104 $104 $103 $103 $81 $81 $81 $81 $81

Weight reduction, 200 lbs TC $739 $720 $701 $683 $665 $626 $610 $599 $589 $578

Weight reduction, 200 lbs Alt 1a

Weight reduction, 200 lbs Alt 3 4% 4% 4% 4% 4% 4% 5%

Weight reduction, 200 lbs TCp $0 $0 $0 $27 $27 $25 $24 $24 $24 $29

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

Table 2-223 Costs for a 200 Pound Weight Reduction

Vocational Light HD Regional Vehicles (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Weight reduction, 200 lbs DMC $635 $616 $597 $579 $562 $545 $529 $518 $508 $498

Weight reduction, 200 lbs IC $104 $104 $104 $103 $103 $81 $81 $81 $81 $81

Weight reduction, 200 lbs TC $739 $720 $701 $683 $665 $626 $610 $599 $589 $578

Weight reduction, 200 lbs Alt 1a

Weight reduction, 200 lbs Alt 3 7% 7% 7% 7% 7% 7% 8%

Weight reduction, 200 lbs TCp $0 $0 $0 $48 $47 $44 $43 $42 $41 $46

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

Table 2-224 Costs for a 200 Pound Weight Reduction

Vocational Medium HD Regional Vehicles (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Weight reduction, 200 lbs DMC $635 $616 $597 $579 $562 $545 $529 $518 $508 $498

Weight reduction, 200 lbs IC $104 $104 $104 $103 $103 $81 $81 $81 $81 $81

Weight reduction, 200 lbs TC $739 $720 $701 $683 $665 $626 $610 $599 $589 $578

Weight reduction, 200 lbs Alt 1a

Weight reduction, 200 lbs Alt 3 6% 6% 6% 6% 6% 6% 7%

Weight reduction, 200 lbs TCp $0 $0 $0 $41 $40 $38 $37 $36 $35 $40

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption

Table 2-225 Costs for a 200 Pound Weight Reduction

Vocational Heavy HD Regional Vehicles (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Weight reduction, 200 lbs DMC $635 $616 $597 $579 $562 $545 $529 $518 $508 $498

Weight reduction, 200 lbs IC $104 $104 $104 $103 $103 $81 $81 $81 $81 $81

Weight reduction, 200 lbs TC $739 $720 $701 $683 $665 $626 $610 $599 $589 $578

Weight reduction, 200 lbs Alt 1a

Weight reduction, 200 lbs Alt 3 5% 5% 5% 5% 5% 5% 6%

Weight reduction, 200 lbs TCp $0 $0 $0 $34 $33 $31 $30 $30 $29 $35

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative; empty cells for adoption rates denote 0% adoption
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-226 Costs for a 400 Pound Weight Reduction

Vocational vehicles (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Weight 

reduction, 400 

lbs

DMC $1,905 $1,848 $1,792 $1,738 $1,686 $1,636 $1,587 $1,555 $1,524 $1,493

Weight 

reduction, 400 

lbs

IC $312 $312 $311 $310 $310 $243 $243 $242 $242 $242

Weight 

reduction, 400 

lbs

TC $2,217 $2,159 $2,103 $2,049 $1,996 $1,879 $1,829 $1,797 $1,766 $1,735

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost; TCp=total cost applied to the package; 

alt=alternative

Table 2-227 Costs for a 1000 Pound Weight Reduction

Vocational vehicles (2012$)

TECHNOLOGY 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Weight 

reduction, 1000 

lbs

DMC $6,349 $6,159 $5,974 $5,795 $5,621 $5,452 $5,289 $5,183 $5,079 $4,978

Weight 

reduction, 1000 

lbs

IC $1,780 $1,770 $1,761 $1,752 $1,743 $1,296 $1,290 $1,286 $1,283 $1,279

Weight 

reduction, 1000 

lbs

TC $8,129 $7,929 $7,735 $7,547 $7,364 $6,748 $6,579 $6,469 $6,362 $6,257

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost

2.12.10.4 Weight reduction in HD pickups and vans

For this proposal, we are estimating weight reduction costs for HD pickups and vans 

using the same cost curve used in support of the 2017-2025 light-duty GHG/CAFE FRM. That 

curve can be expressed as:

Mass Reduction Direct Manufacturing Cost (DMC) ($/lb) = 4.55 x Percentage of Mass 

Reduction (2012$)

For example, this results in an estimated $80 (2012$) DMC increase for a 5 percent mass 

reduction of a 7,000 pound vehicle and $318 (2012$) DMC increase for a 10 percent mass 

reduction of a 7,000 pound vehicle, or $0.227 $/lb and $0.455/lb, respectively (both in 2012$). 

Consistent with the 2017-2025 light-duty FRM, the agencies consider this DMC to be 

applicable to MY2017 and consider mass reduction technology to be on the flat portion of the 

learning curve in the 2017-2025MY timeframe. To estimate indirect costs for applied mass 

reduction of up to 10 percent, the agencies have applied a low complexity ICM with near term 

markups through 2018. 
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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2.12.10.5 Electric power steering, HD pickups and vans

We have based the costs for electric power steering on the costs used in the light-duty

2017-2025 FRM but have scaled upward that cost by 50 percent to account for the larger HD 

vehicles. Using that cost and converting to 2012$ results in a cost of $141 (DMC, 2012$, in 

2015). We consider this technology to be on the flat portion of the learning curve (curve 8) and 

have applied low complexity markups with near term markups through 2018. The resultant costs 

for HD pickups and vans are shown in are shown in Table 2-228.

Table 2-228 Costs for Electric Power Steering

Gasoline & Diesel HD Pickups and Vans (2012$)

ITEM 2021 2022 2023 2024 2025 2026 2027

Electric power steering (EPS) DMC $124 $121 $119 $117 $114 $113 $112

Electric power steering (EPS) IC $27 $27 $27 $27 $27 $27 $27

Electric power steering (EPS) TC $151 $148 $146 $144 $141 $140 $139

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost

2.12.10.6 Low drag brakes, HD pickups and vans

We have based the costs for low drag brakes on the costs used in the light-duty 2017-

2025 FRM but have scaled upward that cost by 50 percent to account for the larger HD vehicles. 

Using that cost and converting to 2012$ results in a cost of $91 (DMC, 2012$, in any year). We 

consider this technology to be beyond the learning curve (curve 1) and have applied low 

complexity markups with near term markups through 2018. The resultant costs for HD pickups 

and vans are shown in are shown in Table 2-229.

Table 2-229 Costs for Low Drag Brakes

Gasoline & Diesel HD Pickups and Vans (2012$)

ITEM 2021 2022 2023 2024 2025 2026 2027

Low drag brakes DMC $91 $91 $91 $91 $91 $91 $91

Low drag brakes IC $18 $18 $18 $18 $18 $18 $18

Low drag brakes TC $109 $109 $109 $109 $109 $109 $109

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost

2.12.10.7 Driveline friction reduction, diesel HD pickups & vans

We have estimated the cost of driveline friction reduction based on the cost of secondary

axle disconnect in the light-duty 2017-2025 final rule. Using that cost of $80 (DMC, 2009$, in 

2015), we have scaled upward by 50 percent to account for the larger HD componentry to arrive 

at a cost of $126 (DMC, 2012$, in 2015). We consider this technology to be on the flat portion 

of the learning curve (curve 3) and have applied low complexity markups with near term 

markups through 2022. The resultant costs for driveline friction reduction (applied only to diesel 

HD pickups & vans) are shown in Table 2-230.
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-230 Costs for Driveline Friction Reduction

Diesel HD Pickups and Vans (2012$)

ITEM 2021 2022 2023 2024 2025 2026 2027

Driveline friction reduction DMC $108 $106 $104 $102 $100 $99 $98

Driveline friction reduction IC $30 $30 $24 $24 $24 $24 $24

Driveline friction reduction TC $139 $136 $128 $126 $124 $123 $122

Notes: DMC=direct manufacturing cost; IC=indirect cost; TC=total cost

2.13Package Costs

Section 0presents detailed technology costs along with adoption rates to illustrate how 

each technology is accounted for in the package costs. Here we present package costs by

regulated sector (i.e., vocational heavy HD, urban vehicles) and package costs by MOVES 

sourcetype (i.e., diesel refuse trucks). We determine package costs by MOVES sourcetype so 

that we can calculate total program costs (i.e., package costs multiplied by vehicle sales) since 

sourcetypes are the sales figures that we can glean from MOVES. As a result, the sourcetype 

package costs presented here are the costs used in our program cost estimations.

2.13.1 Package Costs by Regulated Sector

2.13.1.1 Vocational vehicles

We have estimated costs for 9 vocational segments and 2 fuels. We present package 

costs in Table 2-231 through Table 2-238 for these for alternatives 3 and 4, both relative to 

alternatives 1a and 1b and separately for diesel and gasoline vehicles. 

Table 2-231 Package Costs for Regulated Vocational Segment

Alternative 3 Incremental to Alternative 1a

Diesel (2012$)

WEIGHT CLASS SPEED 2021 2022 2023 2024 2025 2026 2027 2028

Light HD Urban $1,125 $1,100 $1,008 $1,737 $1,701 $1,664 $3,489 $3,427

Light HD Multipurpose $1,125 $1,100 $1,008 $1,737 $1,701 $1,664 $3,490 $3,427

Light HD Regional $598 $585 $563 $849 $835 $819 $1,407 $1,378

Medium HD Urban $1,418 $1,386 $1,254 $2,228 $2,180 $2,132 $4,696 $4,616

Medium HD Multipurpose $1,418 $1,386 $1,254 $2,228 $2,180 $2,132 $4,696 $4,616

Medium HD Regional $571 $559 $537 $817 $803 $788 $1,395 $1,367

Heavy HD Urban $1,998 $1,954 $1,748 $3,332 $3,258 $3,183 $7,422 $7,298

Heavy HD Multipurpose $1,998 $1,954 $1,748 $3,332 $3,258 $3,183 $7,422 $7,298

Heavy HD Regional $3,404 $3,348 $3,160 $4,834 $4,755 $4,683 $4,682 $4,607
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-232 Package Costs for Regulated Vocational Segment

Alternative 3 Incremental to Alternative 1a

Gasoline (2012$)

WEIGHT CLASS SPEED 2021 2022 2023 2024 2025 2026 2027 2028

Light HD Urban $832 $814 $729 $1,299 $1,271 $1,240 $3,086 $3,037

Light HD Multipurpose $832 $814 $729 $1,299 $1,271 $1,240 $3,087 $3,038

Light HD Regional $305 $299 $284 $412 $405 $395 $1,004 $989

Medium HD Urban $1,147 $1,122 $996 $1,823 $1,782 $1,740 $4,327 $4,259

Medium HD Multipurpose $1,147 $1,122 $996 $1,823 $1,782 $1,740 $4,328 $4,259

Medium HD Regional $300 $294 $279 $412 $405 $395 $1,026 $1,010

Heavy HD Urban $1,728 $1,690 $1,491 $2,927 $2,860 $2,791 $7,053 $6,941

Heavy HD Multipurpose $1,728 $1,690 $1,491 $2,927 $2,860 $2,791 $7,053 $6,941

Heavy HD Regional $3,134 $3,083 $2,902 $4,429 $4,357 $4,290 $4,314 $4,251

Table 2-233 Package Costs for Regulated Vocational Segment

Alternative 4 Incremental to Alternative 1a

Diesel (2012$)

WEIGHT CLASS SPEED 2021 2022 2023 2024 2025 2026 2027 2028

Light HD Urban $2,169 $2,120 $1,911 $3,741 $3,661 $3,582 $3,525 $3,462

Light HD Multipurpose $2,169 $2,120 $1,911 $3,704 $3,625 $3,546 $3,490 $3,427

Light HD Regional $805 $788 $756 $1,482 $1,457 $1,430 $1,407 $1,378

Medium HD Urban $2,938 $2,873 $2,560 $5,030 $4,920 $4,810 $4,733 $4,652

Medium HD Multipurpose $2,938 $2,873 $2,560 $4,992 $4,882 $4,772 $4,696 $4,616

Medium HD Regional $777 $760 $729 $1,469 $1,444 $1,417 $1,395 $1,367

Heavy HD Urban $4,337 $4,240 $3,745 $7,895 $7,719 $7,542 $7,422 $7,298

Heavy HD Multipurpose $4,337 $4,240 $3,745 $7,895 $7,719 $7,542 $7,422 $7,298

Heavy HD Regional $2,693 $2,647 $2,504 $4,912 $4,831 $4,752 $4,682 $4,607

Table 2-234 Package Costs for Regulated Vocational Segment

Alternative 4 Incremental to Alternative 1a

Gasoline (2012$)

WEIGHT CLASS SPEED 2021 2022 2023 2024 2025 2026 2027 2028

Light HD Urban $1,796 $1,757 $1,556 $3,322 $3,245 $3,172 $3,122 $3,072

Light HD Multipurpose $1,796 $1,757 $1,556 $3,285 $3,209 $3,136 $3,087 $3,038

Light HD Regional $433 $424 $401 $1,063 $1,041 $1,020 $1,004 $989

Medium HD Urban $2,594 $2,536 $2,232 $4,648 $4,539 $4,435 $4,365 $4,296

Medium HD Multipurpose $2,594 $2,536 $2,232 $4,609 $4,501 $4,398 $4,328 $4,259

Medium HD Regional $432 $423 $400 $1,086 $1,063 $1,042 $1,026 $1,010

Heavy HD Urban $3,992 $3,903 $3,416 $7,512 $7,339 $7,168 $7,053 $6,941

Heavy HD Multipurpose $3,992 $3,903 $3,416 $7,512 $7,339 $7,168 $7,053 $6,941

Heavy HD Regional $2,348 $2,310 $2,175 $4,529 $4,450 $4,378 $4,314 $4,251
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-235 Package Costs for Regulated Vocational Segment

Alternative 3 Incremental to Alternative 1b

Diesel (2012$)

WEIGHT CLASS SPEED 2021 2022 2023 2024 2025 2026 2027 2028

Light HD Urban $1,125 $1,100 $1,008 $1,737 $1,701 $1,664 $3,489 $3,427

Light HD Multipurpose $1,125 $1,100 $1,008 $1,737 $1,701 $1,664 $3,490 $3,427

Light HD Regional $598 $585 $563 $849 $835 $819 $1,407 $1,378

Medium HD Urban $1,418 $1,386 $1,254 $2,228 $2,180 $2,132 $4,696 $4,616

Medium HD Multipurpose $1,418 $1,386 $1,254 $2,228 $2,180 $2,132 $4,696 $4,616

Medium HD Regional $571 $559 $537 $817 $803 $788 $1,395 $1,367

Heavy HD Urban $1,998 $1,954 $1,748 $3,332 $3,258 $3,183 $7,422 $7,298

Heavy HD Multipurpose $1,998 $1,954 $1,748 $3,332 $3,258 $3,183 $7,422 $7,298

Heavy HD Regional $3,404 $3,348 $3,160 $4,834 $4,755 $4,683 $4,682 $4,607

Table 2-236 Package Costs for Regulated Vocational Segment

Alternative 3 Incremental to Alternative 1b

Gasoline (2012$)

WEIGHT CLASS SPEED 2021 2022 2023 2024 2025 2026 2027 2028

Light HD Urban $843 $825 $740 $1,311 $1,282 $1,251 $3,097 $3,048

Light HD Multipurpose $843 $825 $740 $1,311 $1,282 $1,251 $3,097 $3,049

Light HD Regional $316 $310 $295 $423 $416 $406 $1,015 $999

Medium HD Urban $1,159 $1,134 $1,008 $1,835 $1,793 $1,750 $4,338 $4,270

Medium HD Multipurpose $1,159 $1,134 $1,008 $1,835 $1,793 $1,750 $4,339 $4,270

Medium HD Regional $312 $306 $291 $424 $416 $406 $1,037 $1,021

Heavy HD Urban $1,740 $1,702 $1,502 $2,938 $2,871 $2,802 $7,064 $6,952

Heavy HD Multipurpose $1,740 $1,702 $1,502 $2,938 $2,871 $2,802 $7,064 $6,952

Heavy HD Regional $3,146 $3,095 $2,914 $4,441 $4,368 $4,301 $4,324 $4,262

Table 2-237 Package Costs for Regulated Vocational Segment

Alternative 4 Incremental to Alternative 1b

Diesel (2012$)

WEIGHT CLASS SPEED 2021 2022 2023 2024 2025 2026 2027 2028

Light HD Urban $2,169 $2,120 $1,911 $3,741 $3,661 $3,582 $3,525 $3,462

Light HD Multipurpose $2,169 $2,120 $1,911 $3,704 $3,625 $3,546 $3,490 $3,427

Light HD Regional $805 $788 $756 $1,482 $1,457 $1,430 $1,407 $1,378

Medium HD Urban $2,938 $2,873 $2,560 $5,030 $4,920 $4,810 $4,733 $4,652

Medium HD Multipurpose $2,938 $2,873 $2,560 $4,992 $4,882 $4,772 $4,696 $4,616

Medium HD Regional $777 $760 $729 $1,469 $1,444 $1,417 $1,395 $1,367

Heavy HD Urban $4,337 $4,240 $3,745 $7,895 $7,719 $7,542 $7,422 $7,298

Heavy HD Multipurpose $4,337 $4,240 $3,745 $7,895 $7,719 $7,542 $7,422 $7,298

Heavy HD Regional $2,693 $2,647 $2,504 $4,912 $4,831 $4,752 $4,682 $4,607
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-238 Package Costs for Regulated Vocational Segment

Alternative 4 Incremental to Alternative 1b

Gasoline (2012$)

WEIGHT CLASS SPEED 2021 2022 2023 2024 2025 2026 2027 2028

Light HD Urban $1,808 $1,768 $1,567 $3,334 $3,256 $3,183 $3,132 $3,083

Light HD Multipurpose $1,808 $1,768 $1,567 $3,297 $3,220 $3,147 $3,097 $3,049

Light HD Regional $445 $436 $413 $1,075 $1,052 $1,031 $1,015 $999

Medium HD Urban $2,605 $2,547 $2,243 $4,659 $4,550 $4,446 $4,375 $4,306

Medium HD Multipurpose $2,605 $2,547 $2,243 $4,620 $4,512 $4,408 $4,339 $4,270

Medium HD Regional $444 $435 $412 $1,097 $1,074 $1,053 $1,037 $1,021

Heavy HD Urban $4,004 $3,915 $3,428 $7,524 $7,350 $7,178 $7,064 $6,952

Heavy HD Multipurpose $4,004 $3,915 $3,428 $7,524 $7,350 $7,178 $7,064 $6,952

Heavy HD Regional $2,360 $2,321 $2,187 $4,540 $4,461 $4,389 $4,324 $4,262

2.13.1.2 Tractors

We have estimated costs for 7 tractor segments and 1 fuel. We present package costs in 

Table 2-239 through Table 2-242 for these for alternatives 3 and 4, both relative to alternatives 

1a and 1b.

Table 2-239 Package Costs for Regulated Tractor Segment

Alternative 3 Incremental to Alternative 1a

Diesel (2012$)

CLASS TYPE 2021 2022 2023 2024 2025 2026 2027 2028

7 Day cab, low roof $5,468 $5,381 $5,008 $8,400 $8,259 $8,095 $10,140 $9,968

7 Day cab, high roof $5,252 $5,161 $4,811 $8,304 $8,160 $7,913 $10,099 $9,923

8 Day cab, low roof $5,520 $5,432 $5,057 $8,467 $8,325 $8,159 $10,204 $10,031

8 Day cab, high roof $5,298 $5,206 $4,854 $8,419 $8,274 $8,024 $10,209 $10,030

8 Sleeper cab,

low roof

$7,916 $7,786 $7,281 $11,102 $10,912 $10,723 $12,744 $12,548

8 Sleeper cab,

mid roof

$7,916 $7,786 $7,281 $11,102 $10,912 $10,723 $12,744 $12,548

8 Sleeper cab,

high roof

$7,771 $7,637 $7,156 $11,145 $10,952 $10,666 $12,842 $12,640
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-240 Package Costs for Regulated Tractor Segment

Alternative 4 Incremental to Alternative 1a

Diesel (2012$)

CLASS TYPE 2021 2022 2023 2024 2025 2026 2027 2028

7 Day cab, low roof $8,946 $8,799 $8,180 $10,757 $10,574 $10,306 $10,140 $9,968

7 Day cab, high roof $8,769 $8,621 $8,035 $10,851 $10,664 $10,270 $10,099 $9,923

8 Day cab, low roof $8,999 $8,852 $8,230 $10,826 $10,642 $10,371 $10,204 $10,031

8 Day cab, high roof $8,816 $8,666 $8,079 $10,968 $10,780 $10,382 $10,209 $10,030

8 Sleeper cab,

low roof

$11,397 $11,208 $10,456 $13,461 $13,229 $12,934 $12,744 $12,548

8 Sleeper cab,

mid roof

$11,397 $11,208 $10,456 $13,461 $13,229 $12,934 $12,744 $12,548

8 Sleeper cab,

high roof

$11,318 $11,126 $10,411 $13,717 $13,481 $13,039 $12,842 $12,640

Table 2-241 Package Costs for Regulated Tractor Segment

Alternative 3 Incremental to Alternative 1b

Diesel (2012$)

CLASS TYPE 2021 2022 2023 2024 2025 2026 2027 2028

7 Day cab, low roof $5,244 $5,086 $4,642 $7,966 $7,765 $7,564 $9,504 $9,337

7 Day cab, high roof $5,159 $5,040 $4,681 $8,156 $7,995 $7,726 $9,885 $9,710

8 Day cab, low roof $5,296 $5,137 $4,691 $8,033 $7,831 $7,628 $9,569 $9,400

8 Day cab, high roof $5,205 $5,085 $4,724 $8,271 $8,108 $7,836 $9,995 $9,818

8 Sleeper cab,

low roof

$7,642 $7,426 $6,863 $10,610 $10,381 $10,140 $12,078 $11,882

8 Sleeper cab,

mid roof

$7,556 $7,332 $6,770 $10,528 $10,283 $10,044 $11,944 $11,758

8 Sleeper cab,

high roof

$7,653 $7,497 $7,019 $10,996 $10,788 $10,497 $12,640 $12,443

Table 2-242 Package Costs for Regulated Tractor Segment

Alternative 4 Incremental to Alternative 1b

Diesel (2012$)

CLASS TYPE 2021 2022 2023 2024 2025 2026 2027 2028

7 Day cab, low roof $8,721 $8,505 $7,815 $10,323 $10,080 $9,774 $9,504 $9,337

7 Day cab, high roof $8,676 $8,499 $7,905 $10,703 $10,499 $10,083 $9,885 $9,710

8 Day cab, low roof $8,775 $8,557 $7,865 $10,392 $10,148 $9,840 $9,569 $9,400

8 Day cab, high roof $8,722 $8,545 $7,949 $10,820 $10,614 $10,195 $9,995 $9,818

8 Sleeper cab,

low roof

$11,124 $10,848 $10,038 $12,969 $12,698 $12,351 $12,078 $11,882

8 Sleeper cab,

mid roof

$11,037 $10,753 $9,944 $12,887 $12,599 $12,255 $11,944 $11,758

8 Sleeper cab,

high roof

$11,200 $10,985 $10,273 $13,567 $13,317 $12,870 $12,640 $12,443
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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2.13.1.3 Trailers

We have estimated costs for 7 trailer types. We present package costs in Table 2-243 and 

Table 2-244 for these for alternatives 3 and 4 relative to alternative 1a. We present package 

costs in Table 2-245 and Table 2-246 for alternative 3 and 4 relative to alternative 1b.

Table 2-243 Costs for Trailers

Alternative 3 Incremental to Alternative 1a (2012$)

TYPE 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028

53-foot dry van $588 $550 $524 $901 $870 $817 $1,116 $1,083 $1,059 $1,409 $1,396

53-foot reefer van $588 $550 $524 $901 $870 $817 $1,116 $1,083 $1,059 $1,280 $1,267

Container chassis $868 $847 $827 $807 $793 $752 $739 $726 $715 $704 $693

28-foot dry van $514 $501 $489 $974 $957 $923 $1,097 $1,078 $1,065 $1,253 $1,239

Platform $868 $847 $827 $807 $793 $752 $739 $726 $715 $704 $693

Tanker $868 $847 $827 $807 $793 $752 $739 $726 $715 $704 $693

Other highway $868 $847 $827 $807 $793 $752 $739 $726 $715 $704 $693

Table 2-244 Costs for Trailers

Alternative 4 Incremental to Alternative 1a (2012$)

TYPE 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028

53-foot dry van $588 $550 $524 $1,207 $1,172 $1,113 $1,504 $1,465 $1,437 $1,409 $1,396

53-foot reefer van $588 $550 $524 $1,207 $1,172 $1,113 $1,371 $1,333 $1,306 $1,280 $1,267

Container chassis $868 $847 $827 $807 $793 $752 $739 $726 $715 $704 $693

28-foot dry van $514 $501 $489 $1,146 $1,127 $1,090 $1,304 $1,282 $1,267 $1,253 $1,239

Platform $868 $847 $827 $807 $793 $752 $739 $726 $715 $704 $693

Tanker $868 $847 $827 $807 $793 $752 $739 $726 $715 $704 $693

Other highway $868 $847 $827 $807 $793 $752 $739 $726 $715 $704 $693

Table 2-245 Costs for Trailers

Alternative 3 Incremental to Alternative 1b (2012$)

TYPE 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028

53-foot dry van $588 $550 $524 $901 $856 $817 $1,116 $1,083 $1,059 $1,409 $1,382

53-foot reefer van $588 $550 $524 $901 $856 $817 $1,116 $1,083 $1,059 $1,280 $1,254

Container chassis $868 $847 $827 $807 $793 $752 $739 $726 $715 $704 $693

28-foot dry van $514 $501 $489 $974 $957 $923 $1,097 $1,078 $1,065 $1,253 $1,239

Platform $868 $847 $827 $807 $793 $752 $739 $726 $715 $704 $693

Tanker $868 $847 $827 $807 $793 $752 $739 $726 $715 $704 $693

Other highway $868 $847 $827 $807 $793 $752 $739 $726 $715 $704 $693
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-246 Costs for Trailers

Alternative 4 Incremental to Alternative 1b (2012$)

TYPE 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028

53-foot dry van $588 $550 $524 $1,207 $1,157 $1,113 $1,504 $1,465 $1,437 $1,409 $1,382

53-foot reefer van $588 $550 $524 $1,207 $1,157 $1,113 $1,371 $1,333 $1,306 $1,280 $1,254

Container chassis $868 $847 $827 $807 $793 $752 $739 $726 $715 $704 $693

28-foot dry van $514 $501 $489 $1,146 $1,127 $1,090 $1,304 $1,282 $1,267 $1,253 $1,239

Platform $868 $847 $827 $807 $793 $752 $739 $726 $715 $704 $693

Tanker $868 $847 $827 $807 $793 $752 $739 $726 $715 $704 $693

Other highway $868 $847 $827 $807 $793 $752 $739 $726 $715 $704 $693

2.13.1.4 HD Pickups and Vans

The costs presented in Table 2-247 are CAFE model outputs used in this analysis. We 

describe the CAFE model and how these costs were generated in Chapter 11 of this draft RIA.

The costs presented here spread evenly over MYs 2021 through 2026 the costs estimated by the 

CAFE model for MYs 2017-2020.

Table 2-247 Package Costs for HD Pickups and Vans (2012$)

ALTERNATIVE BASELINE CASE 2021 2022 2023 2024 2025 2026 2027

3 1a $516 $508 $791 $948 $1,161 $1,224 $1,342

4 1a $1,050 $1,033 $1,621 $1,734 $1,825 $1,808 $1,841

3 1b $493 $485 $766 $896 $1,149 $1,248 $1,366

4 1b $909 $894 $1,415 $1,532 $1,627 $1,649 $1,684

2.13.2 Package Costs by MOVES Sourcetype

The package costs by segment can then be used to calculate package costs by MOVES 

sourcetype. To do this, we need the percentage of the MOVES sourcetype fleet comprised of 

each regulated sector. Table 2-248 shows this breakout for the vocational sector and Table 2-249

shows it for tractors.
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-248 Fleet Mix by MOVES Sourcetype and Regulated Sector -- Vocationala

ENGINE FUEL SPEED INTERCITY 

BUS

TRANSIT 

BUS

SCHOOL 

BUS

REFUSE 

TRUCKS

SINGLE

UNIT 

SHORT

HAUL

SINGLE

UNIT 

LONG

HAUL

MOTOR 

HOMES

Light 

HD

Gasoline Urban 0% 7% 0% 0% 4% 0% 0%

Light 

HD

Gasoline Multipurpose 0% 20% 1% 0% 49% 0% 0%

Light 

HD

Gasoline Regional 0% 0% 0% 0% 28% 0% 54%

Medium 

HD

Gasoline Urban 0% 2% 0% 0% 1% 0% 0%

Medium 

HD

Gasoline Multipurpose 0% 7% 95% 0% 11% 0% 0%

Medium 

HD

Gasoline Regional 0% 0% 0% 0% 7% 0% 41%

Heavy 

HD

Gasoline Urban 0% 16% 0% 0% 0% 0% 0%

Heavy 

HD

Gasoline Multipurpose 0% 48% 4% 0% 0% 0% 0%

Heavy 

HD

Gasoline Regional 0% 0% 0% 0% 0% 0% 5%

Light 

HD

Diesel Urban 0% 0% 0% 0% 2% 0% 0%

Light 

HD

Diesel Multipurpose 0% 0% 1% 0% 25% 0% 0%

Light 

HD

Diesel Regional 2% 0% 0% 0% 14% 25% 54%

Medium 

HD

Diesel Urban 0% 0% 0% 3% 2% 0% 0%

Medium 

HD

Diesel Multipurpose 0% 0% 95% 0% 20% 0% 0%

Medium 

HD

Diesel Regional 15% 0% 0% 0% 12% 37% 41%

Heavy 

HD

Diesel Urban 0% 25% 0% 97% 1% 0% 0%

Heavy 

HD

Diesel Multipurpose 0% 75% 5% 0% 15% 0% 0%

Heavy 

HD

Diesel Regional 83% 0% 0% 0% 9% 37% 5%

Note:

a Columns add to 100% or 0% for gasoline rows and 100% for diesel rows.
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-249 Fleet Mix by MOVES Sourcetype and Regulated Sector – Tractorsa

ENGINE MOVES

SOURCETYPE

CLASS 

7

DAY 

CAB

LOW 

ROOF

CLASS 

7

DAY 

CAB

HIGH 

ROOF

CLASS 

8

DAY 

CAB

LOW 

ROOF

CLASS 

8

DAY 

CAB

HIGH 

ROOF

CLASS 8

SLEEPER 

CAB

LOW 

ROOF

CLASS 8

SLEEPER 

CAB

MID 

ROOF

CLASS 8

SLEEPER 

CAB

HIGH 

ROOF

Medium 

HD

Combination

Short haul

11% 11%

Heavy 

HD

Combination

Short haul

39% 39%

Heavy 

HD

Combination

Long haul

5% 15% 80%

Note:

a Combination short haul adds to 100% and long haul to 100%; empty cells denote 0%.

Using the fleet mix information shown in Table 2-248 and Table 2-249, along with the 

package costs shown in Table 2-231 through Table 2-246, we can generate the package costs by

MOVES sourcetype (note that package costs by MOVES sourcetype differ from package costs 

by regulated sector only for vocational vehicles and tractors; trailer and HD pickup and van costs 

do not change). These costs are shown in Table 2-250 through Table 2-253.
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-250 Package Costs by MOVES Sourcetype

Alternative 3 Incremental to Alternative 1a (2012$)

SOURCETYPE FUEL 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028

Intercity Bus Diesel $0 $0 $0 $2,913 $2,864 $2,705 $4,138 $4,070 $4,008 $4,112 $4,045

Transit Bus Diesel $0 $0 $0 $1,998 $1,954 $1,748 $3,332 $3,258 $3,183 $7,422 $7,298

School Bus Diesel $0 $0 $0 $1,442 $1,410 $1,275 $2,275 $2,226 $2,177 $4,813 $4,730

Refuse Truck Diesel $0 $0 $0 $1,983 $1,939 $1,735 $3,302 $3,230 $3,156 $7,350 $7,226

SingleUnit 

ShortHaul

Diesel $0 $0 $0 $1,400 $1,371 $1,261 $2,155 $2,112 $2,069 $3,975 $3,905

SingleUnit 

LongHaul

Diesel $0 $0 $0 $1,637 $1,608 $1,525 $2,327 $2,289 $2,252 $2,627 $2,581

MotorHome Diesel $0 $0 $0 $736 $721 $690 $1,047 $1,030 $1,011 $1,576 $1,545

Intercity Bus Gasoline $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

Transit Bus Gasoline $0 $0 $0 $1,434 $1,402 $1,240 $2,388 $2,334 $2,277 $5,736 $5,645

School Bus Gasoline $0 $0 $0 $1,170 $1,145 $1,016 $1,868 $1,826 $1,782 $4,439 $4,368

Refuse Truck Gasoline $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

SingleUnit 

ShortHaul

Gasoline $0 $0 $0 $686 $671 $606 $1,053 $1,031 $1,006 $2,512 $2,472

SingleUnit 

LongHaul

Gasoline $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

MotorHome Gasoline $0 $0 $0 $453 $444 $421 $625 $615 $602 $1,189 $1,170

Comb 

ShortHaul

Diesel $0 $0 $0 $5,398 $5,309 $4,945 $8,423 $8,279 $8,072 $10,187 $10,012

Comb 

LongHaul

Diesel $0 $0 $0 $7,800 $7,667 $7,181 $11,137 $10,944 $10,677 $12,823 $12,622

53’ dry van $588 $550 $524 $901 $870 $817 $1,116 $1,083 $1,059 $1,409 $1,396

53’ rfr van $588 $550 $524 $901 $870 $817 $1,116 $1,083 $1,059 $1,280 $1,267

Container ch $868 $847 $827 $807 $793 $752 $739 $726 $715 $704 $693

28’ dry van $514 $501 $489 $974 $957 $923 $1,097 $1,078 $1,065 $1,253 $1,239

Platform $868 $847 $827 $807 $793 $752 $739 $726 $715 $704 $693

Tanker $868 $847 $827 $807 $793 $752 $739 $726 $715 $704 $693

Other trailer $868 $847 $827 $807 $793 $752 $739 $726 $715 $704 $693

Vocational Diesel $0 $0 $0 $1,366 $1,337 $1,230 $2,102 $2,060 $2,018 $3,892 $3,824

Vocational Gasoline $0 $0 $0 $612 $599 $547 $916 $898 $877 $2,086 $2,053

Vocational Weighted 

Avg

$0 $0 $0 $1,152 $1,128 $1,037 $1,766 $1,731 $1,695 $3,381 $3,323

Tractor Weighted 

Avg

$0 $0 $0 $6,708 $6,605 $6,184 $9,935 $9,774 $9,542 $11,684 $11,503

Trailer Weighted 

Avg

$639 $613 $592 $898 $877 $832 $1,012 $989 $971 $1,165 $1,152

Tractor/Trailer Weighted 

Avg

$639 $613 $592 $7,606 $7,482 $7,016 $10,947 $10,763 $10,513 $12,849 $12,655
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-251 Package Costs by MOVES Sourcetype

Alternative 4 Incremental to Alternative 1a (2012$)

SOURCETYPE FUEL 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028

Intercity Bus Diesel $0 $0 $0 $2,361 $2,320 $2,197 $4,314 $4,243 $4,174 $4,112 $4,045

Transit Bus Diesel $0 $0 $0 $4,337 $4,240 $3,745 $7,895 $7,719 $7,542 $7,422 $7,298

School Bus Diesel $0 $0 $0 $2,997 $2,930 $2,610 $5,115 $5,002 $4,890 $4,813 $4,730

Refuse Truck Diesel $0 $0 $0 $4,300 $4,204 $3,714 $7,819 $7,645 $7,470 $7,350 $7,227

SingleUnit 

ShortHaul

Diesel $0 $0 $0 $2,388 $2,336 $2,109 $4,216 $4,128 $4,040 $3,976 $3,907

SingleUnit 

LongHaul

Diesel $0 $0 $0 $1,500 $1,473 $1,400 $2,760 $2,714 $2,668 $2,627 $2,581

MotorHome Diesel $0 $0 $0 $894 $875 $838 $1,658 $1,630 $1,601 $1,576 $1,545

Intercity Bus Gasoline $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

Transit Bus Gasoline $0 $0 $0 $3,273 $3,201 $2,807 $6,112 $5,971 $5,832 $5,739 $5,648

School Bus Gasoline $0 $0 $0 $2,649 $2,590 $2,279 $4,727 $4,616 $4,510 $4,439 $4,368

Refuse Truck Gasoline $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

SingleUnit 

ShortHaul

Gasoline $0 $0 $0 $1,417 $1,386 $1,235 $2,673 $2,612 $2,554 $2,513 $2,474

SingleUnit 

LongHaul

Gasoline $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

MotorHome Gasoline $0 $0 $0 $534 $524 $495 $1,256 $1,231 $1,207 $1,189 $1,170

Comb 

ShortHaul

Diesel $0 $0 $0 $8,896 $8,748 $8,144 $10,877 $10,691 $10,357 $10,187 $10,012

Comb 

LongHaul

Diesel $0 $0 $0 $11,334 $11,142 $10,420 $13,666 $13,430 $13,018 $12,823 $12,622

53’ dry van $588 $550 $524 $1,207 $1,172 $1,113 $1,504 $1,465 $1,437 $1,409 $1,396

53’ rfr van $588 $550 $524 $1,207 $1,172 $1,113 $1,371 $1,333 $1,306 $1,280 $1,267

Container ch $868 $847 $827 $807 $793 $752 $739 $726 $715 $704 $693

28’ dry van $514 $501 $489 $1,146 $1,127 $1,090 $1,304 $1,282 $1,267 $1,253 $1,239

Platform $868 $847 $827 $807 $793 $752 $739 $726 $715 $704 $693

Tanker $868 $847 $827 $807 $793 $752 $739 $726 $715 $704 $693

Other trailer $868 $847 $827 $807 $793 $752 $739 $726 $715 $704 $693

Vocational Diesel $0 $0 $0 $2,333 $2,282 $2,061 $4,126 $4,041 $3,955 $3,892 $3,825

Vocational Gasoline $0 $0 $0 $1,134 $1,109 $997 $2,218 $2,168 $2,121 $2,087 $2,054

Vocational Weighted 

Avg

$0 $0 $0 $1,994 $1,950 $1,760 $3,586 $3,511 $3,436 $3,382 $3,324

Tractor Weighted 

Avg

$0 $0 $0 $10,225 $10,065 $9,404 $12,431 $12,227 $11,859 $11,684 $11,503

Trailer Weighted 

Avg

$639 $613 $592 $1,084 $1,059 $1,012 $1,231 $1,204 $1,184 $1,165 $1,152

Tractor/Trailer Weighted 

Avg

$639 $613 $592 $11,310 $11,124 $10,416 $13,662 $13,431 $13,043 $12,849 $12,655
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-252 Package Costs by MOVES Sourcetype

Alternative 3 Incremental to Alternative 1b (2012$)

SOURCETYPE FUEL 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028

Intercity Bus Diesel $0 $0 $0 $2,913 $2,864 $2,705 $4,138 $4,070 $4,008 $4,112 $4,045

Transit Bus Diesel $0 $0 $0 $1,998 $1,954 $1,748 $3,332 $3,258 $3,183 $7,422 $7,298

School Bus Diesel $0 $0 $0 $1,442 $1,410 $1,275 $2,275 $2,226 $2,177 $4,813 $4,730

Refuse Truck Diesel $0 $0 $0 $1,983 $1,939 $1,735 $3,302 $3,230 $3,156 $7,350 $7,226

SingleUnit 

ShortHaul

Diesel $0 $0 $0 $1,400 $1,371 $1,261 $2,155 $2,112 $2,069 $3,975 $3,905

SingleUnit 

LongHaul

Diesel $0 $0 $0 $1,637 $1,608 $1,525 $2,327 $2,289 $2,252 $2,627 $2,581

MotorHome Diesel $0 $0 $0 $736 $721 $690 $1,047 $1,030 $1,011 $1,576 $1,545

Intercity Bus Gasoline $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

Transit Bus Gasoline $11 $12 $12 $1,445 $1,414 $1,252 $2,399 $2,345 $2,288 $5,747 $5,655

School Bus Gasoline $11 $12 $12 $1,182 $1,156 $1,028 $1,880 $1,837 $1,793 $4,449 $4,379

Refuse Truck Gasoline $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

SingleUnit 

ShortHaul

Gasoline $11 $12 $12 $697 $683 $617 $1,065 $1,041 $1,017 $2,522 $2,483

SingleUnit 

LongHaul

Gasoline $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

MotorHome Gasoline $11 $12 $12 $465 $456 $432 $636 $625 $613 $1,199 $1,181

Comb 

ShortHaul

Diesel $0 -$59 -$114 $5,240 $5,101 $4,698 $8,132 $7,950 $7,713 $9,763 $9,590

Comb 

LongHaul

Diesel $0 -$70 -$115 $7,638 $7,468 $6,974 $10,906 $10,692 $10,411 $12,508 $12,312

53’ dry van $588 $550 $524 $901 $856 $817 $1,116 $1,083 $1,059 $1,409 $1,382

53’ rfr van $588 $550 $524 $901 $856 $817 $1,116 $1,083 $1,059 $1,280 $1,254

Container ch $868 $847 $827 $807 $793 $752 $739 $726 $715 $704 $693

28’ dry van $514 $501 $489 $974 $957 $923 $1,097 $1,078 $1,065 $1,253 $1,239

Platform $868 $847 $827 $807 $793 $752 $739 $726 $715 $704 $693

Tanker $868 $847 $827 $807 $793 $752 $739 $726 $715 $704 $693

Other trailer $868 $847 $827 $807 $793 $752 $739 $726 $715 $704 $693

Vocational Diesel $0 $0 $0 $1,366 $1,337 $1,230 $2,102 $2,060 $2,018 $3,892 $3,824

Vocational Gasoline $11 $12 $12 $624 $611 $558 $928 $909 $888 $2,096 $2,063

Vocational Weighted 

Avg

$3 $3 $3 $1,156 $1,132 $1,040 $1,770 $1,734 $1,698 $3,384 $3,326

Tractor Weighted 

Avg

$0 -$65 -$114 $6,547 $6,402 $5,958 $9,678 $9,488 $9,235 $11,321 $11,145

Trailer Weighted 

Avg

$639 $613 $592 $898 $870 $832 $1,012 $989 $971 $1,165 $1,146

Tractor/Trailer Weighted 

Avg

$639 $548 $478 $7,445 $7,273 $6,790 $10,690 $10,476 $10,206 $12,487 $12,292
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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Table 2-253 Package Costs by MOVES Sourcetype

Alternative 4 Incremental to Alternative 1b (2012$)

SOURCETYPE FUEL 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028

Intercity Bus Diesel $0 $0 $0 $2,361 $2,320 $2,197 $4,314 $4,243 $4,174 $4,112 $4,045

Transit Bus Diesel $0 $0 $0 $4,337 $4,240 $3,745 $7,895 $7,719 $7,542 $7,422 $7,298

School Bus Diesel $0 $0 $0 $2,997 $2,930 $2,610 $5,115 $5,002 $4,890 $4,813 $4,730

Refuse Truck Diesel $0 $0 $0 $4,300 $4,204 $3,714 $7,819 $7,645 $7,470 $7,350 $7,227

SingleUnit 

ShortHaul

Diesel $0 $0 $0 $2,388 $2,336 $2,109 $4,216 $4,128 $4,040 $3,976 $3,907

SingleUnit 

LongHaul

Diesel $0 $0 $0 $1,500 $1,473 $1,400 $2,760 $2,714 $2,668 $2,627 $2,581

MotorHome Diesel $0 $0 $0 $894 $875 $838 $1,658 $1,630 $1,601 $1,576 $1,545

Intercity Bus Gasoline $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

Transit Bus Gasoline $11 $12 $12 $3,285 $3,212 $2,819 $6,124 $5,981 $5,843 $5,750 $5,659

School Bus Gasoline $11 $12 $12 $2,661 $2,602 $2,290 $4,738 $4,627 $4,521 $4,449 $4,379

Refuse Truck Gasoline $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

SingleUnit 

ShortHaul

Gasoline $11 $12 $12 $1,429 $1,397 $1,246 $2,685 $2,623 $2,565 $2,524 $2,484

SingleUnit 

LongHaul

Gasoline $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

MotorHome Gasoline $11 $12 $12 $546 $535 $507 $1,268 $1,241 $1,218 $1,199 $1,181

Comb ShortHaul Diesel $0 -$59 -

$114

$8,737 $8,540 $7,897 $10,586 $10,361 $9,998 $9,763 $9,590

Comb LongHaul Diesel $0 -$70 -

$115

$11,172 $10,944 $10,212 $13,435 $13,178 $12,752 $12,508 $12,312

53’ dry van $588 $550 $524 $1,207 $1,157 $1,113 $1,504 $1,465 $1,437 $1,409 $1,382

53’ rfr van $588 $550 $524 $1,207 $1,157 $1,113 $1,371 $1,333 $1,306 $1,280 $1,254

Container ch $868 $847 $827 $807 $793 $752 $739 $726 $715 $704 $693

28’ dry van $514 $501 $489 $1,146 $1,127 $1,090 $1,304 $1,282 $1,267 $1,253 $1,239

Platform $868 $847 $827 $807 $793 $752 $739 $726 $715 $704 $693

Tanker $868 $847 $827 $807 $793 $752 $739 $726 $715 $704 $693

Other trailer $868 $847 $827 $807 $793 $752 $739 $726 $715 $704 $693

Vocational Diesel $0 $0 $0 $2,333 $2,282 $2,061 $4,126 $4,041 $3,955 $3,892 $3,825

Vocational Gasoline $11 $12 $12 $1,146 $1,121 $1,009 $2,230 $2,179 $2,132 $2,098 $2,065

Vocational Weighted 

Avg

$3 $3 $3 $1,997 $1,954 $1,763 $3,589 $3,514 $3,439 $3,385 $3,327

Tractor Weighted 

Avg

$0 -$65 -

$114

$10,065 $9,862 $9,179 $12,174 $11,941 $11,552 $11,321 $11,145

Trailer Weighted 

Avg

$639 $613 $592 $1,084 $1,053 $1,012 $1,231 $1,204 $1,184 $1,165 $1,146

Tractor/Trailer Weighted 

Avg

$639 $548 $478 $11,149 $10,915 $10,191 $13,404 $13,144 $12,736 $12,487 $12,292
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

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References

1 Committee to Assess Fuel Economy Technologies for Medium- and Heavy-Duty Vehicles; National Research 

Council; Transportation Research Board (2010). “Technologies and Approaches to Reducing the Fuel Consumption 

of Medium- and Heavy-Duty Vehicles,” (hereafter, “NAS Report”). Washington, D.C., The National Academies 

Press. Available electronically from the National Academies Press Website at 

http://www.nap.edu/catalog.php?record_id=12845 (last accessed September 10, 2010).

2 TIAX, LLC. “Assessment of Fuel Economy Technologies for Medium- and Heavy-Duty Vehicles,” Final Report 

to the National Academy of Sciences, November 19, 2009.

3 U.S. EPA. EPA Lumped Parameter Model HD Version 1.0.0.5, 2010. Docket #EPA-HQ-OAR-2010-0162.

4 NESCCAF, ICCT, Southwest Research Institute, and TIAX. Reducing Heavy-Duty Long Haul Combination 

Truck Fuel Consumption and CO2 Emissions. October 2009.

5

ICF International. Investigation of Costs for Strategies to Reduce Greenhouse Gas Emissions for Heavy-Duty OnRoad Vehicles. July 2010. Docket Identification Number EPA-HQ-OAR-2010-0162-0044. 

6 Reinhart, T.E. (2015, June). Commercial Medium- and Heavy-Duty Truck Fuel Efficiency Technology Study –

Report #1. (Report No. DOT HS 812 146). Washington, DC: National Highway Traffic Safety Administration. 

7 Reinhart, T.E. (2015). Commercial Medium- and Heavy-Duty Truck Fuel Efficiency Technology Study – Report 

#2. Washington, DC: National Highway Traffic Safety Administration.

8

Schubert, R., Chan, M., Law, K. (2015). Commercial Medium- and Heavy-Duty Truck Fuel Efficiency 

Technology Cost Study. Washington, DC: National Highway Traffic Safety Administration.

9 Northeast States Center for a Clean Air Future. “Reducing Greenhouse Gas Emissions from Light-Duty Motor 

Vehicles.” September 2004

10 Energy and Environmental Analysis, Inc. “Technology to Improve the Fuel Economy of Light Duty Trucks to 

2015.” May 2006

11 “Light-Duty Automotive Technology, Carbon Dioxide Emissions, and Fuel Economy Trends: 1975 - 2014”, EPA420-R-14-023, October 2014. Available at http://www.epa.gov/otaq/fetrends.htm (last accessed October 31, 2014).

12 “Development and Optimization of the Ford 3.5L V6 EcoBoost Combustion System,” Yi,J., Wooldridge, S., 

Coulson, G., Hilditch, J. Iyer, C.O., Moilanen, P., Papaioannou, G., Reiche, D. Shelby, M., VanDerWege, B., 

Weaver, C. Xu, Z., Davis, G., Hinds, B. Schamel, A. SAE Technical Paper No. 2009-01-1494, 2009, Docket EPAHQ-OAR-2009-0472-2860.

13 David Woldring and Tilo Landenfeld of Bosch, and Mark J. Christie of Ricardo, “DI Boost: Application of a 

High Performance Gasoline Direct Injection Concept,” SAE 2007-01-1410. Available at 

http://www.sae.org/technical/papers/2007-01-1410 (last accessed Nov. 9, 2008)

14 Yves Boccadoro, Loïc Kermanac’h, Laurent Siauve, and Jean-Michel Vincent, Renault Powertrain Division, “The 

New Renault TCE 1.2L Turbocharged Gasoline Engine,” 28th Vienna Motor Symposium, April 2007.

15 Tobias Heiter, Matthias Philipp, Robert Bosch, “Gasoline Direct Injection: Is There a Simplified, Cost-Optimal 

System Approach for an Attractive Future of Gasoline Engines?” AVL Engine & Environment Conference, 

September 2005.

16 Stanton, Donald. “Enabling High Efficiency Clean Combustion.” 2009 Semi-Mega Merit Review of the 

Department of Energy. May 21, 2009. Last accessed on August 25, 2010 at 

http://www1.eere.energy.gov/vehiclesandfuels/pdfs/merit_review_2009/advanced_combustion/ace_40_stanton.pdf.

17 Zhang, H. Heavy Truck Engine Development & HECC. 2009 DOE Semi-Mega Merit Review, May 21, 2009. 

Last accessed on August 25, 2010 at 

http://www1.eere.energy.gov/vehiclesandfuels/pdfs/merit_review_2009/advanced_combustion/ace_42_zhang.pdf

18 de Ojeda, W., SuperTruck – Development and Demonstration of a Fuel-Efficient Class 8 Tractor & Trailer Engine 

Systems, http://energy.gov/eere/vehicles/downloads/supertruck-development-and-demonstration-fuel-efficient-class8-tractor-3

19 Zhang, H. Detroit Diesel. “High Efficiency Clean Combustion for Heavy-Duty Engine.” August 6, 2008 

presentation to DEER Conference. Last accessed on August 25, 2010 at 

http://www1.eere.energy.gov/vehiclesandfuels/pdfs/deer_2008/session5/deer08_zhang.pdf
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

2-286

 

20 Singh, S., SuperTruck Program: Engine Project Review Recovery Act – Class 8 Truck Freight Efficiency 

Improvement Project, DOE Supertruck Merit Review, Department of Energy, 2014.

21 See the NAS Report, page 53 cites Detroit Diesel Corporation, DD15 Brochure, DDC-EMC-BRO-0003-0408, 

April 2008

22 Greszler, A., “View from the Bridge – Commercial Vehicle Perspective,” DEER Conference, Department of 

Energy, 2012. http://www1.eere.energy.gov/vehiclesandfuels/resources/proceedings/2012_deer_presentations.html

23 de Ojeda, W., “Development and Demonstration of A Fuel-Efficient HD Engine (Department of Energy 

Supertruck Program),” DEER Conference, Department of Energy, 2012. 

http://www1.eere.energy.gov/vehiclesandfuels/resources/proceedings/2012_deer_presentations.html

24 Jadin, D., “SuperTruck – Development and Demonstration of a Fuel-Efficient Class 8 Tractor & Trailer,” DOE 

Supertruck Merit Review, Department of Energy, 2012. 

http://www1.eere.energy.gov/vehiclesandfuels/resources/proceedings/2012_deer_presentations.html

25 Koeberlein, D., Technology and System Level Demonstration of Highly Efficient and Clean, Diesel Powered 

Class 8 Trucks, 2012, http://energy.gov/sites/prod/files/2014/03/f10/ace057_koeberlein_2012_o.pdf

26 Sisken, K., Rotz, D., “Recovery Act – Class 8 Truck Freight Efficiency Improvement Project,” DOE Supertruck 

Merit Review, Department of Energy, 2012. 

http://www1.eere.energy.gov/vehiclesandfuels/resources/proceedings/2012_deer_presentations.html

27 de Ojeda, W., “Development and Demonstration of A Fuel-Efficient HD Truck,” DEER Conference, Department 

of Energy, 2011, 

http://www1.eere.energy.gov/vehiclesandfuels/resources/proceedings/2011_deer_presentations.html

28 SAE Off-Highway Magazine. Federal-Mogul’s Latest Piston Ring Developments help reduce friction in heavyduty engines. October 2, 2014. Last accessed on October 3, 2014 at 

http://www.oemoffhighway.com/press_release/12007334/federal-moguls-latest-piston-ring-developments-helpreduce-friction-in-heavy-duty-engines

29 Sisken, K., SuperTruck Program: Engine Project Review Recovery Act – Class 8 Truck Freight Efficiency 

Improvement Project, DOE Supertruck Merit Review, Department of Energy, 2013

30 Amar, P., SuperTruck Development and Demonstration of a Fuel-Efficient Class 8 Highway Vehicle Systems, 

DOE Supertruck Merit Review, Department of Energy, 2013

31 Koeberlein, D., Technology and System Level Demonstration of Highly Efficient and Clean, Diesel Powered 

Class 8 Trucks, DOE Supertruck Merit Review, Department of Energy, 2013

32 Stanton, D. W., Systematic development of highly efficient and clean engines to meet future commercial vehicle 

greenhouse gas regulations. Presented at SAE Commercial Vehicle Engineering Congress. Chicago, IL, October 

2013

33 Amar, P., Volvo SuperTruck Powertrain Technologies for Efficiency Improvement, DOE Supertruck Merit 

Review, Department of Energy, 2014.

34 Rotz, D., Super Truck Program: Vehicle Project Review, DOE Supertruck Merit Review, Department of Energy, 

2014.

35 Damon, K., DOE SuperTruck Program – Technology and System Level Demonstration of Highly Efficient b and 

Clean, Diesel Powered Class 8 Trucks, DOE Supertruck Merit Review, Department of Energy, 2014.

36 Assumes travel on level road at 65 MPH. (21st Century Truck Partnership Roadmap and Technical White Papers, 

December 2006. U.S. Department of Energy, Energy Efficiency and Renewable Energy Program. 21CTP-003. p. 

36.)

37 Reducing Heavy-Duty Long Haul Combination Truck Fuel Consumption and CO2 Emissions, ICCT, October 

2009

38 Overdrive magazine September 2014, “Western Star introduces re-designed on-highway tractor,” 

http://www.overdriveonline.com/photo-video-western-star-unveils-re-designed-on-highwaytractor/?utm_medium=overdrive&utm_campaign=site_click&utm_source=top_stories

39 Cornelius Pfeifer (Rochling Automotive), Society of Automotive Engineer (SAE) Paper #2014-01-0633: 

“Evolution of Active Grille Shutters.” April 1, 2014.

40 Jason Leuschen and Kevin R. Cooper (National Research Council of Canada), Society of Automotive Engineer 

(SAE) Paper #2006-01-3456: “Full-Scale Wind Tunnel Tests of Production and Prototype, Second-Generation 

Aerodynamic Drag-Reducing Devices for Tractor-Trailers.”, November 2, 2006.

41 http://www.todaystrucking.com/supertruck-flies-to-future-of-fuel-efficiency-at-107-mpg.
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

2-287

 

42 “Tires & Truck Fuel Economy,” A New Perspective. Bridgestone Firestone, North American Tire, LLC, Special 

Edition Four, 2008. 

43 “Michelin’s Green Meters,” Press Kit, October, 30, 2007. http://www.michelin-greenmeter.com/main.php?cLang=en (Complete Press File, Viewed March 6, 2010)

44 Argonne National Laboratory. “Evaluation of Fuel Consumption Potential of Medium and Heavy Duty Vehicles 

through Modeling and Simulation.” October 2009. Page 91.

45 21st Century Truck Partnership, “Roadmap and technical White Papers”, U.S. Department of Energy, Technical 

paper: 21CTP-0003, December 2006.

46 NACFE December 2010 “Executive Report – Wide Base Tires”, available at http://nacfe.org/wpcontent/uploads/2010/12/NACFE-ER-1002-Wide-Base-Tires-Dec-2010.pdf

47 “Energy Efficiency Strategies for Freight Trucking: Potential Impact on Fuel Use and Greenhouse Gas 

Emissions,” J. Ang-Olson, W. Schroer, Transportation Research Record: Journal of the Transportation Research 

Board, 2002(1815):11-18. 

48 “Effect of Single Wide Tires and Trailer Aerodynamics on Fuel efficiency and NOX Emissions of Class 8 LineHaul Tractor-Trailer,” J. Bachman, A. Erb, C. Bynum, U.S. Environmental Protection Agency, SAE International, 

Paper Number 05CV-45, 2005. 

49 “Class 8 Heavy Truck Duty Cycle Project Final Report,” U.S. Department of Energy, Oak Ridge National 

Laboratory, ORNL/TM-2008/122, p. 21, December 2008. Accessed January 19, 2010 at 

http://cta.ornl.gov/cta/Publications/Reports/ORNL_TM_2008-122.pdf. 

50 “Are Ultra-Wide, Ultra-Low Aspect Ratio Tires the Next Big Thing?” K. Rohlwing, Today’s Tire Industry, Vol. 

1, Issue 1, July/August, July 2003.

51 “New Generation Wide Base Single Tires,” American Trucking Association, White paper presented at the 

International Workshop on the use of wide tires sponsored by Federal Highway Administration, Turner-Fairbank 

Highway Research Center, October 25-26, 2007, Revision 9, December 21, 2007, Accessed on February 3, 2010 at 

http://www.arc.unr.edu/Workshops/Wide_Tires/Wide_Base_Summary-v9-ATA-whitepaper.pdf

52 HDT Trucking info, March 2014,”Switching to Wide-Base Singles: Keys to Success,” Available online: 

http://www.truckinginfo.com/channel/equipment/article/story/2014/03/switching-to-wide-base-singles-keys-tosuccess.aspx

53 “Recommended Practice: Guidelines for Outset Wide Base Wheels for Drive, Trailer and Auxiliary Axle 

Applications (Draft),” Technology and Maintenance Council, Council of American Trucking Associations, 

circulated September 28, 2009. 

54 “Tire Pressure Systems - Confidence Report”. North American Council for Freight Efficiency. 2013. Available 

online: http://nacfe.org/wp-content/uploads/2014/01/TPS-Detailed-Confidence-Report1.pdf

55 Technology and Maintenance Council of the American Trucking Associations, Tire Air Pressure Study, Tire 

Debris Prevention Task Force S.2 Tire & Wheel Study Group; May 2002.

56 “Commercial Vehicle Tire Condition Sensors,” Federal Motor Carrier Safety Administration. Report No. 

FMCSA-PSV-04-002, November 2003.

57 U.S. Environmental Protection Agency Office of Transportation and Air Quality SmartWay Transport 

Partnership, A Glance at Clean Freight Strategies: Automatic Tire Inflation Systems EPA 420-F-04-0010; February 

2004. 

58 ”A Day in the Life of a Tire”, Pressure Systems International, Presented to EPA on August 20, 2014.

59 “Buses & Retread Tires,” The Tire Retread & Repair Information Bureau, Pacific Grove, Ca., Accessed on 

January 27, 2010 at http://www.retread.org/packet/index.cfm/ID/284.htm. 

60 “What are Retreaders Doing to Improve Fuel Efficiency?” H. Inman, Tire Review, December 11, 2006, Accessed 

on February 18, 2010 at 

http://www.tirereview.com/Article/59777/what_are_retreaders_doing_to_improve_fuel_efficiency.aspx

61 Modern Tire Dealer, Top Retreaders, ibid.

62 Tire Industry Association and the Tire Retread and Repair Information Bureau, Understanding Retreading, 

accessed August 2, 2010, at http://www.retread.org/pdf/UR/UnderstandingRetreading_web.pdf

63 Todaystrucking.com, Retread Tires FAQ (07/17/2006), accessed August 2, 2010.

64 “Better Fuel efficiency? Start with a Strong Tire Program,” H. Inman, Fleet & Tire 2006, Tire Review, December 

11, 2006, Accessed on February 18, 2010 at http://www.tirereview.com/better-fuel-economy-start-with-a-strongtire-program/ 
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

2-288

 

65 See 2010 NAS Report, Note 1, Finding 4-6, page 87.

66 See NHTSA Technology Report #1 (2015), Note 6. 

67 NACFE. Executive Report – 6x2 (Dead Axle) Tractors. November 2010. See Docket

68 Reinhart, T.E. (2015, June). Commercial Medium- and Heavy-Duty Truck Fuel Efficiency Technology Study –

Report #1. (Report No. DOT HS 812 146). Washington, DC: National Highway Traffic Safety Administration. 

69 Fleet Owner, “Meritor Expects to offer new tandem axle in 2013,” http://fleetowner.com/equipment/meritorexpects-offer-new-tandem-axle-2013, December 2012.

70 Dana Holding Corporation Patents (8,523,738, 8,795,125, and 8,911,321)

71 See 4WD Axle Actuator Housing at 1A Auto, accessed November 2014 from http://www.1aauto.com/4wd-axleactuator-housing/c/264

72 DriveAluminum. The Aluminum Advantage in Commercial Vehicle Applications Webinar. 2009. Last accessed 

on May 21, 2015 at 

http://www.drivealuminum.org/research-resources/PDF/Webinars/2009/The-Aluminum-Advantage-CommercialVehicle-Applications-Webinar-2009-Dec-Commercial-Vehicle-Webinar.pdf/view

73 Committee on the Assessment of Technologies for Improving Light-Duty Vehicle Fuel Economy; National 

Research Council, “Assessment of Fuel Economy Technologies for Light-Duty Vehicles”, 2011. Available at 

http://www.nap.edu/catalog.php?record_id=12924 (last accessed Jun 27, 2012)

74 Energy Savings through Increased Fuel Economy for Heavy Duty Trucks”, Therese Langer,

American Council for an Energy-Efficient Economy prepared for the National Commission on Energy

Policy, February 11, 2004

75 Best practices Guidebook for Greenhouse Gas Reductions in Freight Transportation”, H.

Christopher Fey, Po-Yao Kuo, North Carolina State University prepared for the U.S. Department of

Transportation, October 4, 2007

76 U.S. EPA. http://www.epa.gov/smartway/documents/weightreduction.pdf

77 SAE World Congress, “Focus B-pillar ‘tailor rolled’ to 8 different thicknesses,” Feb. 24, 2010. Available at 

http://www.sae.org/mags/AEI/7695 (last accessed Jun. 10, 2012)

78 “Preliminary Vehicle Mass Estimation Using Empirical Subsystem Influence Coefficients,” Malen, D.E., Reddy, 

K. Auto-Steel Partnership Report, May 2007, Docket EPA-HQ-OAR-2009-0472-0169. Accessed on the Internet on 

May 30, 2009 at: http://www.a-sp.org/database/custom/Mass%20Compounding%20-%20Final%20Report.pdf

79 “Benefit Analysis: Use of Aluminum Structures in Conjunction with Alternative Powertrain Technologies in 

Automobiles,” Bull, M. Chavali, R., Mascarin, A., Aluminum Association Research Report, May 2008, Docket 

EPA-HQ-OAR-2009-0472-0168. Accessed on the Internet on April 30, 2009 at: 

http://www.autoaluminum.org/downloads/IBIS-Powertrain-Study.pdf

80 American Trucking Association. Last viewed on January 29, 2010 at 

http://www.trucksdeliver.org/recommendations/speed-limits.html

81 U.S. EPA SmartWay Transport Partnership. Last viewed on January 28, 2010 at 

http://www.epa.gov/smartway/transport/documents/tech/reducedspeed.pdf

82 Department for Transport, Vehicle and Operator Services Agency. Last viewed on January 6, 2010 at 

http://www.dft.gov.uk/vosa/newsandevents/pressreleases/2006pressreleases/28-12-06speedlimiterlegislation.htm

83 Transport Canada. Summary Report – Assessment of a Heavy Truck Speed Limiter Requirement in Canada. Last 

viewed on January 6, 2010 at http://www.tc.gc.ca/eng/roadsafety/tp-tp14808-menu-370.htm

84 See TIAX 2009, Note 2, at page 4-98.

85 Gaines, L. and D. Santini. Argonne National Laboratory, Economic Analysis of Commercial Idling Reduction 

Technologies

86 ICF International. Investigation of Costs for Strategies to Reduce Greenhouse Gas Emissions for Heavy-Duty OnRoad Vehicles. July 2010. Docket Identification Number EPA-HQ-OAR-2010-0162-0044

87 NACFE, June 2014. Confidence Report: Idle-Reduction Solutions. Available at 

http://www.carbonwarroom.com/sites/default/files/reports/Idle-Reduction_Confidence_Report.pdf (accessed 

November 2014)

88 See Vanner battery-inverter Systems at http://www.vanner.com/

89 See eNow solar systems. http://www.enowenergy.com/.

90 Schwarz, W., Harnisch, J. 2003. “Establishing Leakage Rates of Mobile Air Conditioners.” Prepared for the 

European Commission (DG Environment), Doc B4-3040/2002/337136/MAR/C1
*** E.O. 12866 Review – REVISED – Do Not Cite, Quote, or Release During Review ***

2-289

 

91 Vincent, R., Cleary, K., Ayala, A., Corey, R. 2004. “Emissions of HFC-134a from Light-Duty Vehicles in 

California.” SAE 2004-01-2256

92 Society of Automotive Engineers, “IMAC Team 1 – Refrigerant Leakage Reduction, Final Report to Sponsors,” 

2006

93 California Air Resources Board. Letter from Michael Carter to Matthew Spears dated December 3, 2014. Solar 

Control: Heavy-Duty Vehicles White Paper. Docket EPA-HA-OAR-2014-0827. 

94 National Renewal Energy Laboratory. Reducing Long-Haul Truck Idle Loads and Resulting Fuel Use. Presented 

by Jason A. Lustbader to EPA on July 29, 2014. See Docket EPA-HA-OAR-2014-0827.

95 See NHTSA Technology Report #1 (2015), Note 6.

96 U.S. EPA and NHTSA, “Final Rulemaking to Establish Light-Duty Vehicle Greenhouse Gas Emission Standards 

and Corporate Average Fuel Economy Standards – Joint Technical Support Document,” 2010. Last viewed on June 

3, 2010 at http://www.epa.gov/otaq/climate/regulations/420r10901.pdf

97 “Light-Duty Automotive Technology, Carbon Dioxide Emissions, and Fuel Economy Trends: 1975 - 2014”, EPA420-R-14-023, October 2014. Available at http://www.epa.gov/otaq/fetrends.htm (last accessed October 31, 2014).

98 “Development and Optimization of the Ford 3.5L V6 EcoBoost Combustion System,” Yi,J., Wooldridge, S., 

Coulson, G., Hilditch, J. Iyer, C.O., Moilanen, P., Papaioannou, G., Reiche, D. Shelby, M., VanDerWege, B., 

Weaver, C. Xu, Z., Davis, G., Hinds, B. Schamel, A. SAE Technical Paper No. 2009-01-1494, 2009, Docket EPAHQ-OAR-2009-0472-2860.

99 David Woldring and Tilo Landenfeld of Bosch, and Mark J. Christie of Ricardo, “DI Boost: Application of a 

High Performance Gasoline Direct Injection Concept,” SAE 2007-01-1410. Available at 

http://www.sae.org/technical/papers/2007-01-1410 (last accessed Nov. 9, 2008)

100 Yves Boccadoro, Loïc Kermanac’h, Laurent Siauve, and Jean-Michel Vincent, Renault Powertrain Division, 

“The New Renault TCE 1.2L Turbocharged Gasoline Engine,” 28th Vienna Motor Symposium, April 2007.

101 Tobias Heiter, Matthias Philipp, Robert Bosch, “Gasoline Direct Injection: Is There a Simplified, Cost-Optimal 

System Approach for an Attractive Future of Gasoline Engines?” AVL Engine & Environment Conference, 

September 2005.

102 U.S. EPA and NHTSA, “Final Rulemaking to Establish Light-Duty Vehicle Greenhouse Gas Emission Standards 

and Corporate Average Fuel Economy Standards – Joint Technical Support Document,” 2010. Last viewed on June 

3, 2010 at http://www.epa.gov/otaq/climate/regulations/420r10901.pdf

103 “All-new-Ford-engineered, Ford-tested, Ford-built diesel maximizes 2011 Super Duty productivity,” Ford press 

release, August 3, 2010. Available at: http://www.media.ford.com (last accessed June 27, 2011).

104 Stanton, Donald. “Enabling High Efficiency Clean Combustion.” 2009 Semi-Mega Merit Review of the 

Department of Energy. May 21, 2009. Last accessed on August 25, 2010 at 

http://www1.eere.energy.gov/vehiclesandfuels/pdfs/merit_review_2009/advanced_combustion/ace_40_stanton.pdf.

105 Committee on the Assessment of Technologies for Improving Light-Duty Vehicle Fuel Economy; National 

Research Council, “Assessment of Fuel Economy Technologies for Light-Duty Vehicles”, 2011. Available at 

http://www.nap.edu/catalog.php?record_id=12924 (last accessed Jun 27, 2012)

106 SAE World Congress, “Focus B-pillar ‘tailor rolled’ to 8 different thicknesses,” Feb. 24, 2010. Available at 

http://www.sae.org/mags/AEI/7695 (last accessed Jun. 10, 2012)

107 “2008/9 Blueprint for Sustainability,” Ford Motor Company. Available at: http:// 

www.ford.com/go/sustainability (last accessed February 8, 2010).

108 “2015 North American Light Vehicle Aluminum Content Study – Executive Summary”, June 2014, 

http://www.drivealuminum.org/research-resources/PDF/Research/2014/2014-ducker-report (last accessed February 

26, 2015)

109 Fox News September 2014, “Ford confirms increased aluminum use on next-gen Super Duty pickups,” 

http://www.foxnews.com/leisure/2014/09/30/ford-confirms-increased-aluminum-use-on-next-gen-super-dutypickups/ (last accessed February 2015)

110 “Mass Reduction and Cost Analysis – Light-Duty Pickup Trucks Model Years 2020-2025”, FEV, North 

America, Inc., April 2015, Document no. EPA-420-R-15-006

111 Michelin. SAE Presentation. 

112 U.S. Department of Energy. Transportation Energy Data Book, Edition 28-2009. Table 5.7.

113 Gaines, L., A. Vyas, J. Anderson. Estimation of Fuel Use by Idling Commercial Trucks. January 2006.

114 Mack 2010 Powertrain Brochure
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2-290

 

115 Joint Technical Support Document: Final Rulemaking for 2017-2025 Light-Duty Vehicle Greenhouse Gas 

Emission Standards and Corporate Average Fuel Economy Standards, August 2012, available at 

http://www.epa.gov/otaq/climate/documents/420r12901.pdf

116 Vehicle Valuation Services, Inc, 2000, available at http://www.vvsi.com/training/TrainingGuide.pdf (accessed 

June 2014)

117 See Cummins-Eaton partnership at http://smartadvantagepowertrain.com/

118 See TIAX 2009, Note 2 at 4.5.2

119 See TIAX 2009, Note 2, Table 4-48

120

 Heavy Duty Trucking October 2014, “2015 Medium-Duty Truck Trends,” 

http://www.truckinginfo.com/channel/equipment/article/story/2014/10/2015-medium-duty-trucks-the-vehicles-andtrends-to-look-for/page/3.aspx (downloaded November 2014)

121 See NACFE Confidence Report: Electronically Controlled Transmissions, at 

http://www.truckingefficiency.org/powertrain/automated-manual-transmissions (January 2015). See also 

http://www.overdriveonline.com/auto-vs-manual-transmission-autos-finding-solid-ground-by-sharing-data-withengines/ (accessed November 2014)

122 See Eaton Announcement September 2014, available at 

http://www.ttnews.com/articles/lmtbase.aspx?storyid=2969&t=Eaton-Unveils-Medium-Duty-ProcisionTransmission

123 Light-Duty Technology Cost Analysis, Report on Additional Case Studies, Revised final Report, EPA-420-R-13-

008, page 2-16, April 2013, available at http://www.epa.gov/otaq/climate/documents/420r13008.pdf

124 Lammert, M., Walkowivz, K., NREL, Eighteen-Month Final Evaluation of UPS Second Generation Diesel 

Hybrid-Electric Delivery Vans, September 2012, NREL/TP-5400-55658

125 Green Fleet Magazine, The Latest Developments in EV Battery Technology, November 2013, available at 

http://www.greenfleetmagazine.com/article/story/2013/12/the-latest-developments-in-ev-battery-technologygrn/page/1.aspx

126 Van Amburg, Bill, CALSTART, Status Report: Alternative Fuels and High-Efficiency Vehicles, Presentation to 

National Association of Fleet Administrators (NAFA) 2014 Institute and Expo, April 8, 2014

127 See NHTSA Technology Report #1 (2015), Note 6. See T-270 Delivery Truck Vehicle Technology Results

128 Heavy Duty Trucking, “Rise of the 6x2”, May 2013, accessed from 

http://www.truckinginfo.com/article/story/2013/05/rise-of-the-6x2.aspx

129 NACFE, Confidence Findings on the Potential of 6x2 Axles, available at http://nacfe.org/wpcontent/uploads/2014/01/Trucking-Efficiency-6x2-Confidence-Report-FINAL-011314.pdf, January 2014 

(downloaded November 2014).

130 See NHTSA Technology Report #1 (2015), Note 6.

131 Argonne National Laboratory. “Evaluation of Fuel Consumption Potential of Medium and Heavy Duty Vehicles 

through Modeling and Simulation.” October 2009. Page 91.

132 See SwRI Technology Report 1 (2014), Note 6. See Section 3.3.4.3 T270 Delivery Truck Vehicle Technology 

Results.

133 See memorandum dated May 2015 on Vocational Vehicle Tire Rolling Resistance Test Data Evaluation.

134 See NREL data at http://www.nrel.gov/vehiclesandfuels/fleettest/research_fleet_dna.html

135 See memorandum dated May 2015 on Analysis of Possible Vocational Vehicle Standards Based on Alternative 

Idle Cycle Weightings

136 See NHTSA Technology Report #1 (2015) Note 6, T-270 and F-650 weight reduction results

137 See TIAX 2009, Note 2.

138 The Minnesota refrigerant leakage data can be found at

http://www.pca.state.mn.us/climatechange/mobileair.html#leakdata

139 See Phase 1 RIA, Chapter 2.7

140 Society of Automotive Engineers, “IMAC Team 1 – Refrigerant Leakage Reduction, Final Report

to Sponsors,” 2006

141 Society of Automotive Engineers Surface Vehicle Standard J2727, issued August 2008,

http://www.sae.org

142 EPA Docket memo on Vocational Aerodynamics, May 2015

143 See http://westcoastcollaborative.org/files/sector-fleets/WCC-LA-BEVBusinessCase2011-08-15.pdf
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2-291

 

144 Silver, Fred, and Brotherton, Tom. (CalHEAT) Research and Market Transformation Roadmap to 2020 for 

Medium- and Heavy-Duty Trucks. California Energy Commission, June 2013.

145 Gallo, Jean-Baptiste, and Jasna Tomic (CalHEAT). 2013. Battery Electric Parcel Delivery Truck Testing and 

Demonstration. California Energy Commission.

146 See Ford announcement December 2013, 

https://media.ford.com/content/fordmedia/fna/us/en/news/2013/12/12/70-percent-of-ford-lineup-to-have-auto-startstop-by-2017--fuel-.html. See also Allison-Cummins announcement July 2014, 

http://www.oemoffhighway.com/press_release/12000208/allison-stopstart?utm_source=OOH+Industry+News+eNL&utm_medium=email&utm_campaign=RCL140723006

147 “Tires & Truck Fuel Economy: A New Perspective”, The Tire Topic Magazine, Special Edition Four, 2008, 

Bridgestone Firestone, North American Tire, LLC. Available online: 

http://www.trucktires.com/bridgestone/us_eng/brochures/pdf/08-Tires_and_Truck_Fuel_Economy.pdf

148 Truck Trailer Manufacturers Association letter to EPA. October 16, 2014. Docket EPA-HQ-OAR-2014-0827

149 “Tire Pressure Systems - Confidence Report”. North American Council for Freight Efficiency. 2013. Available 

online: http://nacfe.org/wp-content/uploads/2014/01/TPS-Detailed-Confidence-Report1.pdf

150 ”A Day in the Life of a Tire”, Pressure Systems International, Presented to EPA on August 20, 2014.

152 Federal Motor Carriers Safety Administration, “Commercial Vehicle Tire Condition Sensors,” conducted by 

Booz-Allen-Hamilton, Inc. November, 2003.

153 TMC Technology & Maintenance Council, “TMC Tire Air Pressure Study,” May 2002

154 FMCSA “Advanced Sensors and Applications: Commercial Motor Vehicle Tire Pressure Monitoring and 

Maintenance,” February 2014

155 “Underinflated Commercial Low Rolling Resistance Truck Tires & It’s Impact on Fuel Economy”, October 

2010. Pressure Systems International, Presentation Material shared with EPA on May 21, 2014.

156 Scarcelli, Jamie. "Fuel Efficiency for Trailers" Presented at ACEEE/ICCT Workshop: Emerging Technologies 

for Heavy-Duty Vehicle Fuel Efficiency, Wabash National Corporation. July 22, 2014

157 "Weight Reduction: A Glance at Clean Freight Strategies", EPA SmartWay. EPA420F09-043. Available at: 

http://permanent.access.gpo.gov/gpo38937/EPA420F09-043.pdf

158 Memo to docket regarding confidential weight reduction information obtained during SBREFA Panel, June 4, 

2015

159 Randall Scheps, Aluminum Association, “The Aluminum Advantage: Exploring Commercial Vehicles 

Applications,” presented in Ann Arbor, Michigan, June 18, 2009

160 http://energy.gov/eere/articles/supertruck-making-leaps-fuel-efficiency

161 Truck Trailer Manufacturers Association letter to EPA. October 16, 2014. Docket EPA-HQ-OAR-2014-0827

162 Ben Sharpe (ICCT) and Mike Roeth (North American Council for Freight Efficiency), “Costs and Adoption 

Rates of Fuel-Saving Technologies for Trailer in the North American On-Road Freight Sector”, Feb 2014

163 Frost & Sullivan, “Strategic Analysis of North American Semi-trailer Advanced Technology Market”, Feb 2013

164 ICF International. Investigation of Costs for Strategies to Reduce Greenhouse Gas Emissions for Heavy-Duty 

On-Road Vehicles. July 2010. See also, TIAX, LLC. “Assessment of Fuel Economy Technologies for Mediumand Heavy-Duty Vehicles,” Final Report to the National Academy of Sciences, November 19, 2009.

165 Schubert, R., Chan, M., Law, K. (2015). Commercial Medium- and Heavy-Duty (MD/HD) Truck Fuel Efficiency 

Cost Study. Washington, DC: National Highway Traffic Safety Administration, Tetra Tech Technology Cost Report 

(2015), Note 8.

166 Schubert, R., Chan, M., Law, K. (2015). Commercial Medium- and Heavy-Duty Truck Fuel Efficiency 

Technology Cost Study. Washington, DC: National Highway Traffic Safety Administration.

167 A. Rogozhin et al., Int. J. Production Economics 124 (2010) 360–368.

168 RTI International. Heavy Duty Truck Retail Price Equivalent and Indirect Cost Multipliers. July 2010.

169 Rogozhin, A., et al., “Using indirect cost multipliers to estimate the total cost of adding new technology in the 

automobile industry,” International Journal of Production Economics (2009), doi:10.1016/j.ijpe.2009.11.031.

170 Helfand, Gloria, and Todd Sherwood, “Documentation of the Development of Indirect Cost Multipliers for Three 

Automotive Technologies,” August 2009.

171 RTI International. Heavy Duty Truck Retail Price Equivalent and Indirect Cost Multipliers. July 2010.

172 See “Learning Curves in Manufacturing”, L. Argote and D. Epple, Science, Volume 247; “Toward Cost Buy 

down Via Learning-by-Doing for Environmental Energy Technologies, R. Williams, Princeton University, 
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2-292

 

Workshop on Learning-by-Doing in Energy Technologies, June 2003; “Industry Learning Environmental and the 

Heterogeneity of Firm Performance, N. Balasubramanian and M. Lieberman, UCLA Anderson School of 

Management, December 2006, Discussion Papers, Center for Economic Studies, Washington DC.

173 See “Learning Curves in Manufacturing”, L. Argote and D. Epple, Science, Volume 247; “Toward Cost Buy 

down Via Learning-by-Doing for Environmental Energy Technologies, R. Williams, Princeton University, 

Workshop on Learning-by-Doing in Energy Technologies, June 2003; “Industry Learning Environments and the 

Heterogeneity of Firm Performance, N. Balasubramanian and M. Lieberman, UCLA Anderson School of 

Management, December 2006, Discussion Papers, Center for Economic Studies, Washington DC.

174 U.S. Energy Information Administration, Annual Energy Outlook 2014, Early Release; Report Number 

DOE/EIA-0383ER (2014), December 16, 2013.

175 Bureau of Economic Analysis, Table 1.1.9 Implicit Price Deflators for Gross Domestic Product; as revised on 

March 27, 2014.

176 Business Case for Battery-Electric Trucks in Los Angeles, California, at 

http://westcoastcollaborative.org/files/sector-fleets/WCC-LA-BEVBusinessCase2011-08-15.pdf, last accessed on 

12/8/2014.

177

 Ben Sharpe (ICCT) and Mike Roeth (North American Council for Freight Efficiency), “Costs and Adoption 

Rates of Fuel-Saving Technologies for Trailer in the North American On-Road Freight Sector”, Feb 2014.