UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

NATIONAL VEHICLE AND FUEL EMISSIONS LABORATORY

2565 PLYMOUTH ROAD

ANN ARBOR, MI 48105-2498

 OFFICE OF

 AIR AND RADIATION

1

April 14, 2015

MEMORANDUM

SUBJECT: Example Compliance Scenarios for Proposed HD GHG Phase 2 Trailer Program

FROM: Jessica Brakora, Tad Wysor, Mechanical Engineers, Assessment and Standards Division

TO: Greenhouse Gas Emissions Standards and Fuel Efficiency Standards for Medium- and 

Heavy-Duty Engines and Vehicles - Phase 2 - Docket EPA-HQ-OAR-2014-0827

Introduction

As described in the Phase 2 HD GHG and Fuel Consumption Notice of Proposed Rulemaking, 

EPA and NHTSA are proposing the first CO2 emissions and fuel consumption regulations for trailer 

manufacturers. The trailer industry has no experience with the process for complying with EPA 

emissions or NHTSA fuel consumption regulations. The concept of averaging, which is proposed as an 

optional compliance flexibility for trailer manufacturers, may add complexity to a process that is already 

unfamiliar to vehicle manufacturers that are not currently regulated. The purpose of this memo is to 

provide a set of hypothetical examples of how a trailer manufacturer might comply with the Phase 2 

standards while meeting the needs of a variety of customers.

In this memo, we provide example scenarios to illustrate some of the different compliance 

options that would be available to trailer manufacturers in the proposed program. The first set of 

scenarios presented is for model year (MY) 2021, representing an earlier stage of the proposed phase-in. 

A second set of scenarios is presented for MY 2027, when we are proposing the program to be fully 

phased-in. We performed this analysis in terms of grams of CO2 per ton-mile; use a conversion of 

10,180 grams of CO2 per gallon of diesel to calculate the fuel consumption values.

Compliance Options Available in Proposed Trailer Program

The primary approach for a trailer manufacture to comply with the proposed program is for 

every trailer produced to meet the proposed standards. The agencies expect a variety of technology 

combinations from several device manufacturers would satisfactorily meet the proposed standards, and a 

manufacturer would be able to offer its customers some flexibility in the choice of technology packages 

they purchase. Trailer manufacturers that opt for this primary compliance approach would take on 

basic recordkeeping and reporting responsibilities.
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Historically, EPA has created provisions that allow vehicle manufacturers the option of 

averaging, banking, and trading within their sales mix, which provides an additional flexibility for 

manufacturers to achieve compliance. Averaging provisions allow a vehicle manufacturer to produce 

and sell trailers that under-comply with the standards as long as they make up for those sales with 

sufficient over-compliant trailers. Banking and trading provisions allow vehicle manufacturers to carryover or sell end-of-year credits generated from over-compliance. This proposal does not include 

banking or trading provisions for the proposed trailer program, since the agencies believe these 

provisions would disproportionately impact the large number of small businesses in the trailer industry. 

See the preamble to this NPRM for a more detailed discussion of these impacts. 

The agencies are proposing averaging provisions as a compliance flexibility for trailer 

manufacturers for all model years of the program. As will be shown in the examples to follow, an 

averaging compliance approach would allow a trailer manufacturer to offer its customers a greater 

number of technology options, since not all trailers sold are required to meet the proposed standards. 

Customers would have the option of purchasing technology packages that meet or exceed the standards, 

or they could choose to avoid purchasing some technologies. Trailer manufacturers that opt for an 

averaging compliance approach would have additional recordkeeping responsibilities in that they must 

ensure that their sales of adequately over-compliant trailers exceed their under-compliant sales. These 

manufacturers would also have to submit an additional end-of-year report describing their averaging 

strategy. 

Summary of Performance Levels for Trailer Technologies

As discussed in the preamble to this proposed rulemaking and its accompanying draft RIA, the 

agencies evaluated several existing technologies and created metrics to evaluate their performance. 

Table 1 presents performance levels described in the proposal for aerodynamic technologies, lower 

rolling resistance tires, and automatic tire inflation (ATI) systems, and provides example technologies 

for reference. Delta CDA is the change in drag area, which is a measure of aerodynamic performance. 

The tire rolling resistance level (TRRL) is the regulatory term for the coefficient of rolling resistance 

(CRR) that a trailer manufacturer uses in compliance. 

Table 1: Summary of Performance Levels and Example Technologies 

Aerodynamics CDA (m2

) Example Technologies

Bin I 0.0 No Aero 

Bin II 0.1 Gap Reducer 

Bin III 0.3 Basic Skirt or Tail 

Bin IV 0.5 Advanced Skirt or Tail 

Bin V 0.7 Optimized Skirts, Basic Combos

Bin VI 1.0 Skirt/Tail Combo

Bin VII 1.4 Optimized Advanced Combos 

Bin VIII 1.8 Future Devices/Redesign

Tire Rolling Resistance TRRL (kg/ton) Example Technologies

Baseline 6.00 Baseline Tires

Level 1 5.10 SmartWay Tires

Level 2 4.70 Top 25% SmartWay Tires

Tire Inflation Effectiveness Description

ATI 1.5% Automatic Tire Inflation 
Example Trailer Compliance Scenarios / Docket EPA-HQ-OAR-2014-0827

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The proposed regulations include a list of 12 light-weight components and six tire/wheel options 

that a manufacturer could install on its trailers for weight reduction. For simplification in this set of 

examples, we are combining some of these components into four packages. The first two packages are 

the substitution of standard steel wheels with aluminum wheels. Package 1 substitutes eight dual-wide 

steel wheels with eight aluminum wheels, and Package 2 substitutes eight steel wheels with four 

aluminum wide-based single wheels and tires for additional weight savings. Package 3 is a combination 

of weight savings by installing aluminum versions of four components found on the underside of box 

trailers: landing gear (50 lb), slider box (150 lb), suspension assembly (280 lb), and upper coupler 

assembly (430 lb). Package 4 is a combination of five aluminum trailer body components: roof bows 

(100 lb), rear door surround (150 lb), rear door (187 lb), floor crossmembers (203 lb), side posts (300), 

and the complete floor (375). Table 2 summarizes the weight savings for each package.

Table 2: Summary of Weight Reduction Packages Used in Compliance Examples

Weight Reduction Weight Reduced (lbs) Description

Base 0 Standard Components

Package 1 168 Aluminum Dual Wheels

Package 2 556 Aluminum Wide-Based Single Wheels

Package 3 910 Underside Components

Package 4 1315 Trailer Body Components

The performance parameters for aerodynamics and tires are combined with the combined weight 

savings from any light-weight component substitutions and the improvement for use of ATI to 

determine CO2 emissions and fuel consumption from a tractor-trailer vehicle. The agencies developed 

an equation for trailer manufacturers to combine the effects of these technologies and calculate CO2

emissions for compliance. The equation is based on the EPA’s heavy-duty vehicle simulation tool, the 

Greenhouse gas Emissions Model (GEM), that is used for compliance by other heavy-duty vehicle 

sectors. Equation 1 is the proposed equation for long box dry vans.

(1)

The performance parameters (i.e., CRR andCDA) for tire rolling resistance and aerodynamic 

technologies would be established from testing. The tests could be performed by the trailer 

manufacturer, or the trailer manufacturer may obtain performance parameters from aerodynamic device 

or tire manufacturers who performed the testing. The weight reduction (WR) value would be a sum of 

the approved light-weight components that are installed on the trailer. The constant, C5, is equal to 

0.985 (to account for the 1.5 percent improvement) if a trailer installs ATI, otherwise it is 1.0. 

Throughout this memo, Equation 1 is used to calculate the CO2 emissions. As mentioned previously, we 

performed this analysis in terms of grams of CO2 per ton-mile; use a conversion of 10,180 grams of CO2

per gallon of diesel to calculate the corresponding fuel consumption values for compliance with 

NHTSA’s regulations.

Description of Example Customers

In each example scenario described in this memo, we considered a long box dry van 

manufacturer that sells a total of 100 trailers to four customers with different needs and preferences for 
Example Trailer Compliance Scenarios / Docket EPA-HQ-OAR-2014-0827

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their orders. Table 3 introduces the four customers, their preferences, and their order sizes. For 

simplicity, the customers and the number of trailers in their orders remain the same in each scenario 

presented. We recognize that manufacturers may produce more than a single type of trailer, sell more 

than 100 trailers, and have more than four customers. The concepts presented here can be easily 

translated to larger production volumes and the other regulated trailer subcategories. A short description 

of some of the subcategory differences is provided at the end of these examples. 

Table 3: Description of Customers for Example Compliance Scenarios

Customer Typical Application Acceptance of Technologies Units in Order

1 Short- and long-haul Reluctant to adopt aero 30

2 Mostly short-haul Reluctant to adopt any tech 10

3 Mostly long-haul Willing to adopt all tech 40

4 Mostly long-haul Reluctant to adopt ATI 20

Example Compliance Scenarios 

Under the primary proposed compliance provisions, long and short box van manufacturers could 

produce all of their regulated trailers to meet the standards. Alternatively, these manufacturers would be 

allowed to use averaging within a model year, in which case some of their trailer production could 

under-comply if enough of their other trailers over-complied. This set of examples describes situations 

where a manufacturer was assumed to use both proposed approaches, with and without averaging, for

compliance. The first set of scenarios present the primary, non-averaging compliance approach, and the 

second set uses the averaging compliance approach.

Each set of scenarios includes examples for model year (MY) 2021, which represents an early 

stage of the proposed phase-in, and MY 2027, when we are proposing the program to be fully phased-in. 

In the early stages of the program, the proposed standards could be met with the use of technologies at 

lower performance levels. As a result, more technology options would be available to comply with the 

standards than later in the program when the standards would become more stringent. If some 

customers are reluctant to adopt certain technologies, the manufacturer would be able to offer several 

alternatives that have similar performance levels. Once the program is fully phased-in in MY 2027, the 

standards would be more stringent and it is less likely that trailer manufacturers would be able to rely on 

reduced-technology packages meeting the standards. 

Primary Compliance Scenarios

The primary strategy for a manufacturer to comply with the proposed standard would be for all 

of its regulated trailers to perform at or better than the applicable standard for that model year. Below 

are descriptions of two example scenarios that adopt this compliance approach. The first scenario offers 

more flexibility for customers to choose technology packages based on their preferences. A trailer 

manufacturer adopting this approach would likely evaluate several technology combinations to ensure 

each of the trailers sold meet the standards, which may require some additional recordkeeping. The 

second scenario describes a very simplistic strategy for achieving the proposed standards for the given 

model year. The trailer manufacturer’s customers in this second scenario would still maintain some 

choice in technology options, but only a limited set of combinations would be offered. This scenario 

would require the least amount of recordkeeping for the trailer manufacturer.
Example Trailer Compliance Scenarios / Docket EPA-HQ-OAR-2014-0827

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Example 1: MY 2021 Primary Compliance Scenario

In the first example, a manufacturer is opting to use the primary compliance approach, and wants

to satisfy its customer’s preferences as much as possible, while still meeting the standards. Table 4

illustrates how a manufacturer might provide technology packages for the four customers described in 

Table 3. The proposed CO2 standard for long box dry vans in MY 2021 is 81 gCO2/ton-mi. Each trailer 

sold in this scenario met or exceeded the standard, as shown at the bottom of Table 4. In a primary 

compliance scenario, the trailer manufacturer does not receive any benefit from over-compliant trailers 

(i.e., those sold to Customers 3 and 4). 

Under the primary compliance approach, no customers could purchase under-compliant trailers. 

In this case, Customer 1 wanted to minimize aerodynamic technologies, but was willing to order a very 

basic tail device (Bin III) on its trailers. To make up for the lower aero performance, Customer 1 

ordered tires with the lowest rolling resistance, an ATI system, and the largest weight-reduction 

package. Similarly, Customer 2 reluctantly ordered trailers with modest aerodynamics (Bin III), but 

chose to install lighter-weight component packages, including single wide tires, on its trailers in order to 

avoid ATI and the highest performing tires. Customers 3 and 4 met chose to purchase trailers with 

higher-performing aerodynamic packages and tires. Customer 3 installed ATI systems, Bin VI

aerodynamics, and level 2 tires on all of its trailers. Customer 4 opted for some weight reduction 

packages in order to avoid the use of ATI systems. 

Table 4: Example Technology Adoption Rates for Four Customers in a MY 2021 Flexible Primary Compliance 

Scenario

Long Dry Van Cust 1 Cust 2 Cust 3 Cust 4

0.0 Aero Bin I 

0.1 Aero Bin II 

0.3 Aero Bin III 100% 100%

0.5 Aero Bin IV

0.7 Aero Bin V 100%

1.0 Aero Bin VI 100%

1.4 Aero Bin VII

1.8 Aero Bin VIII

Average Delta CdA 0.3 0.3 1.0 0.7

6.00 Baseline 0% 0% 0% 0%

5.10 TRRL 1 100%

4.70 TRRL 2 100% 100% 100%

Average CRR 4.7 5.1 4.7 4.7

1.50 Adopt ATI 100% 100%

ATI 1.5% 0.0% 1.5% 0.0%

0 None

168 WR Package 1 100%

556 WR Package 2 100%

910 WR Package 3 100%

1315 WR Package 4 100% 100% 100%

Weight Reduction 1315 2781 0 1483

Customer CO2 (g/ton-mi) = 81 81 78 80

Customer Order (trailers) = 30 10 40 20
Example Trailer Compliance Scenarios / Docket EPA-HQ-OAR-2014-0827

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Prior to the model year, a manufacturer adopting a similar compliance strategy as shown in Table 

4 may wish to consider and keep track of which combination of technologies would result in compliant 

trailers when deciding the technology packages to offer to its customers. The trailer manufacturer would

not need to analyze its sales throughout the year as long as each of the trailers sold continued to meet the 

standards. At the end of the year, this trailer manufacturer would submit a production report to the 

agencies that includes the production volumes and performance of the trailers sold. A detailed 

description of the reporting and recordkeeping requirements is available in 40 CFR 1037.250. 

Example 2: MY 2021 Simplified Primary Compliance Scenario

The simplified primary compliance example is shown in Table 5. In this example, the trailer 

manufacturer established a base set of technologies for all of its trailers to ensure that every trailer was

compliant. Every trailer sold includes at least Bin V aerodynamic technologies, Level 1 rolling 

resistance tires, and an ATI system. The trailer manufacturer in this scenario would not restrict the 

purchase of additional technologies, as demonstrated by Customers 3 and 4 choosing to purchase trailers 

with higher-performing aerodynamic technologies and light-weight components, respectively. 

Table 5: Example Technology Adoption Rates for Four Customers in a MY 2021 Simplified Primary 

Compliance Scenario

Long Dry Van Cust 1 Cust 2 Cust 3 Cust 4

0.0 Aero Bin I 

0.1 Aero Bin II 

0.3 Aero Bin III 

0.5 Aero Bin IV

0.7 Aero Bin V 100% 100% 100%

1.0 Aero Bin VI 100%

1.4 Aero Bin VII

1.8 Aero Bin VIII

Average Delta CdA 0.7 0.7 1.0 0.7

6.00 Baseline 0% 0% 0% 0%

5.10 TRRL 1 100% 100% 100% 100%

4.70 TRRL 2

Average CRR 5.1 5.1 5.1 5.1

1.50 Adopt ATI 100% 100% 100% 100%

ATI 1.5% 1.5% 1.5% 1.5%

0 None

168 WR Package 1

556 WR Package 2

910 WR Package 3

1315 WR Package 4 100%

Weight Reduction 0 0 0 1315

Customer CO2 (g/ton-mi) = 81 81 79 79

Customer Order (trailers) = 30 10 40 20
Example Trailer Compliance Scenarios / Docket EPA-HQ-OAR-2014-0827

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While this simplified compliance scenario reduces the number of options the manufacturer has to 

offer its customers, it maintains a degree of flexibility by not requiring the use of a single make or model 

of any technology. Several vendors and technology models are available today that meet these 

qualifications, and the trailer manufacturer would be able to allow its customers some choice of specific 

technologies to apply. Specifically, many of the aerodynamic technologies currently verified by 

SmartWay are expected to perform at Bin V levels, so manufacturers would have many options in terms 

of device design and manufacturer. Similarly, Baseline tires are those that meet the SmartWay threshold 

for verification, and thus there would be many such tire options. The agencies are also aware of at least 

four ATI systems from three manufacturers that manufacturers could choose. 

The reduced flexibility of this simplified compliance scenario provides the trailer manufacturer 

with the lowest compliance burden of the options evaluated in this memo. The manufacturer would only 

need to evaluate technology packages that meet the baseline performance criteria and ensure every 

trailer sold included a minimum of that base technology package. Any additional technologies added to 

a trailer would result in over-compliance and would not benefit the manufacturer in this scenario. The 

manufacturers would still need to submit an end-of-year production report to summarize the year’s sales 

and confirm that a baseline performance package was installed on each trailer sold. 

Example 3: MY 2027 Primary Compliance Scenario

The proposed trailer program would be fully phased-in by MY 2027. The CO2 standard for long 

box dry vans is 77 g/ton-mi in MY 2027, and the trailers sold by the trailer manufacturer would have to 

include higher performing technologies to comply. In this set of primary compliance examples, all 

trailers sold will have to meet the standard. As seen in Table 6, the trailer manufacturer could not design 

a compliant trailer with less than Bin V aerodynamics. Equation 1 indicates that aerodynamic 

improvements to long dry vans are more than three times as effective at reducing CO2 compared to the 

other technologies. Consequently, none of the other technology options were effective enough to make 

up for a lack of aerodynamic improvement in the fully phased-in program.

Customer 1 was initially reluctant to include aero on its trailer, but was given a great deal on a 

Bin V aerodynamic package for its order. It completed its compliant trailers order with TRRL 2 tires 

and ATI systems, and several weight reduction packages. Customer 2 was reluctant to order any 

technologies for its trailers, but settled on slightly more aero and weight reduction to avoid both ATI and 

the higher level of tires. Customers 3’s order from MY 2021 was very close to compliant with the MY 

2027 standard, and the customer opted to order trailers with more advanced aero, which exceeded the 

standard. Customer 4 chose Bin VI aero and an additional weight reduction package in order to 

continue to avoid purchasing ATI systems. 

As noted previously, trailer manufacturers that produce over-compliant trailers do not receive 

any benefit from in them in a primary compliance strategy. However, some trailer manufacturers may 

consider the relatively few recordkeeping and reporting requirements to be an acceptable compromise. 

Similar to Example 2, a manufacturer may choose a minimum set of technologies to its customers to 

ensure compliance in MY 2027. The process is similar to the previous example and an additional 

example is not shown for this standard.
Example Trailer Compliance Scenarios / Docket EPA-HQ-OAR-2014-0827

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Table 6: Example Technology Adoption Rates for Four Customers in a MY 2027 Primary Compliance Scenario

Long Dry Van Cust 1 Cust 2 Cust 3 Cust 4

0.0 Aero Bin I 

0.1 Aero Bin II 

0.3 Aero Bin III 

0.5 Aero Bin IV

0.7 Aero Bin V 100%

1.0 Aero Bin VI 100% 100%

1.4 Aero Bin VII 100%

1.8 Aero Bin VIII

Average Delta CdA 0.7 1.0 1.4 1.0

6.00 Baseline 0% 0% 0% 0%

5.10 TRRL 1 100%

4.70 TRRL 2 100% 100% 100%

Average CRR 4.7 5.1 4.7 4.7

1.50 Adopt ATI 100% 100%

ATI 1.5% 0.0% 1.5% 0.0%

0 None

168 WR Package 1 100%

556 WR Package 2 100% 100%

910 WR Package 3 100% 100% 100%

1315 WR Package 4 100% 100% 100%

Weight Reduction 2781 2781 0 2393

Customer CO2 (g/ton-mi) = 77 77 76 77

Customer Order (trailers) = 30 10 40 20

Summary of the Primary Compliance Approach

If a trailer manufacturer opted to use the primary compliance approach, it could offer any 

number of combinations to its customers, as long as each combination met the standard. Trailer 

manufacturers could allow customers to choose from any combination of compliant trailers (e.g., 

Examples 1 and 3) or establish a minimum set of technologies for every trailer sold to ensure 

compliance (e.g., Example 2). In the compliance scenarios described so far, each customer ordered a 

single set of trailer technologies. Of course, customers may wish to purchase multiple combinations of 

trailer technologies in a single order, and this can easily be accomplished using the primary compliance 

approach. The certification application and end-of-year reporting requirements for a trailer 

manufacturer would not change significantly by offering a greater number of compliant trailer options. 
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Averaging Compliance Scenarios 

In the following scenarios, the trailer manufacturer chose to use the proposed averaging 

provisions. This compliance approach allows the manufacturer to offer its customers the largest range 

of technology options for their trailers. These examples will show that the four customers’ technology 

preferences that were outlined previously in Table 3 could be better reflected in an averaging scenario; 

the customers that wanted fewer (or no) technologies could be accommodated. However, it will also be 

shown that a trailer manufacturer adopting an averaging scenario would have additional reporting and 

recordkeeping requirements, and would likely need to consider both the performance level and 

production volume of their trailers sold throughout the model year to ensure end-of-year compliance. 

Example 4: MY 2021 Averaging Compliance Scenario

During the certification application process, a manufacturer that wishes to use the averaging 

provisions would identify trailer “subfamilies” that have similar performance. The technology packages

used in each subfamily would have unique target performance values, or Family Emission Limits

(FELs). In the primary (non-averaging) compliance strategy, subfamilies are not necessary, since every 

trailer produced would meet the standards. In an averaging compliance strategy, as described next, a 

production-weighted average of the FELs is used to determine compliance. 

Table 7 illustrates the technology choices of the four customers in this averaging scenario. 

Similar to the primary compliance example, Customer 3 was willing to order trailers that include several 

of the more advanced technologies (i.e., Bin VI aerodynamics, tires with the lowest rolling resistance, 

ATI systems). Since Customer 3 has the largest order, the trailer manufacturer encouraged it include 

weight-reducing component substitutions, which resulted in additional CO2 reductions for the trailer 

manufacturer. The same 81 gCO2/ton-mi standard applies in this scenario, and Customer 3’s order

resulted in CO2 reductions well below what was needed for the manufacturer to comply with the 

standard. Because of this over-compliance for part if its production, the manufacturer could offer 

trailers with fewer technologies to its other customers. 

Customer 1 was reluctant to order trailers with aerodynamic technologies, but was willing to 

order them with lower rolling resistance tires, ATI systems, and two weight reduction options. The 

absence of aerodynamics on these trailers still led to an under-compliant FEL at 83 g/ton-mi that the 

manufacturer would need to offset with sales of over-complying trailers to other customers. Customer 2 

preferred not to adopt any of the technologies and the FEL for its order was 88 g/ton-mi, representative 

of the zero-technology baseline for long-box dry vans. Customer 4, which did not want to order ATI 

systems, was still willing to order trailers with some significantly-effective aerodynamics, the lowest 

rolling resistance tires, and some light-weight components, which resulted in a compliant FEL of 81

g/ton-mi. 
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Table 7: Example Technology Adoption Rates for Four Customers in a MY 2021 Averaging Scenario with Four 

Subfamilies

Long Dry Van Cust 1 Cust 2 Cust 3 Cust 4

0.0 Aero Bin I 100% 100%

0.1 Aero Bin II 

0.3 Aero Bin III 

0.5 Aero Bin IV

0.7 Aero Bin V 100%

1.0 Aero Bin VI 100%

1.4 Aero Bin VII

1.8 Aero Bin VIII

Average Delta CdA 0.0 0.0 1.0 0.7

6.00 Baseline 0% 100% 0% 0%

5.10 TRRL 1

4.70 TRRL 2 100% 100% 100%

Average CRR 4.7 6.0 4.7 4.7

1.50 Adopt ATI 100% 100%

ATI 1.5% 0.0% 1.5% 0.0%

0 None 100%

168 WR Package 1

556 WR Package 2

910 WR Package 3

1315 WR Package 4 100% 100%

Weight Reduction 1315 0 1315 0

Customer CO2 (g/ton-mi) = 83 88 77 81

Customer Order (trailers) = 30 10 40 20

In this scenario, the manufacturer has calculated a CO2 value for each customer’s order. Since 

each order results in a unique CO2 value, each trailer order becomes a subfamily within the long dry van 

family, and the CO2 results become the FELs for the subfamilies. The manufacturer would calculate a 

production-weighted average of all its FELs as follows: 30% x 83g/ton-mi + 10% x 88g/ton-mi + 40% x 

77g/ton-mi + 20% x 81g/ton-mi to arrive at the overall compliance level of 81g/ton-mi. Since this level 

matched the standard in this example, the manufacturer would be in compliance with the standard for 

that model year. 

Example 5: MY 2021 Averaging Compliance Scenario with Additional Subfamilies

To further illustrate averaging, we assume that some of the customers ordered the same number 

of trailers, but with multiple technologies. Table 8 provides one example of multiple technologies for 

the different customers. Customer 1 preferred that half of its order install level 2 tires with ATI and the 

other half install level 3 tires without ATI. Customer 2 continued to order trailers with no technologies. 

Customer 3 wanted a few of its trailers to have lower-performing aerodynamic technology. Customer 4 

preferred to split its order among three different aerodynamic technologies. 
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Table 8: Example Technology Adoption Rates for Four Customers in a MY 2021 Averaging Scenario with 

Additional Subfamilies

Long Dry Van Cust 1 Cust 2 Cust 3 Cust 4

0.0 Aero Bin I 100% 100%

1.0 Aero Bin II 

0.0 Aero Bin III 

0.0 Aero Bin IV 30%

0.0 Aero Bin V 10% 60%

0.0 Aero Bin VI 90% 10%

0.0 Aero Bin VII

0.3 Aero Bin VIII

Average Delta CdA 0.0 0.0 1.0 0.7

6.00 Baseline 0% 100% 0% 0%

5.10 TRRL 1 50%

4.70 TRRL 2 50% 100% 100%

Average CRR 4.9 6.0 4.7 4.7

1.50 Adopt ATI 50% 100%

ATI 0.8% 0.0% 1.5% 0.0%

0 None 100%

168 WR Package 1

556 WR Package 2

910 WR Package 3

1315 WR Package 4 100% 100%

Weight Reduction 1315 0 1315 0

Customer Order (trailers) = 30 10 40 20

Each unique trailer technology combination shown in Table 8 has the potential to result in 

different trailer performance. Table 9 shows the CO2 levels for the different trailer packages, along with 

the number of trailers with those technologies, in each customer’s order. Subfamilies are identified by 

CO2 level (i.e., FEL). The order from Customer 3, colored pink in Table 9, includes four trailers with a 

technology package that results in an FEL of 79 g/ton-mi. The technology package on a pair of trailers

in Customer 4’s order also resulted in an FEL of 79 g/ton-mi. These two trailer sets from different 

orders with different technologies could be combined into a single subfamily for compliance purposes. 

The remaining trailer orders resulted in unique FELs and would be considered separate subfamilies. 

Table 9: Example Compliance Results for MY 2021 Averaging Scenario with Additional Subfamilies

Cust 1 Cust 2 Cust 3 Cust 4

Customer CO2 (g/ton-mi) = 83 84 88 79 77 82 81 79

Customer Order (trailers) = 15 15 10 4 36 6 12 2

The manufacturer in this averaging scenario would have produced a total of seven subfamilies. 

Each subfamily results in a unique FEL, which is used to calculate manufacturer’s production-weighted 

average as follows: 15% x 83 g/ton-mi + 15% x 84 g/ton-mi + 10% x 88 g/ton-mi + 4% x 79 g/ton-mi + 

36% x 77 g/ton-mi + 6% x 82 g/ton-mi + 12% x 81 g/ton-mi + 2% x 79 g/ton-mi. The calculation 

results in an overall compliance value of 81 g/ton-mi, which is also in compliance with the standard for 
Example Trailer Compliance Scenarios / Docket EPA-HQ-OAR-2014-0827

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MY 2021. Compared to the averaging scenario presented in Example 3, the variety of technology 

packages in Example 4 results in more subfamilies, additional recordkeeping and a few more 

calculations. 

Example 6: MY 2027 Averaging Compliance Scenario

The proposed MY 2027 CO2 standard for long box dry vans is 77 g/ton-mi. As shown in , 

Customer 3 again ordered the most advanced technologies, including Bin VII aero the tires at the highest 

level, ATI, and two weight reduction packages. As a result, the manufacturer over-complied with the 

MY 2027 standard for this order with an FEL of 74 g/ton-mi. As in the MY 2021 averaging scenario, 

this would allow the manufacturer to offer lower-performing technology options to other customers. 

Customer 1 was willing to order the TRRL 2 tires, ATI, and significant weigh reduction, as it did 

in Example 3. However, this trailer manufacturer was able to offer this customer under-compliant 

trailers with Bin IV aero (instead of Bin V, which was needed in Example 3) for an FEL at 78 g/ton-mi. 

In this example, Customer 2 was able to order trailers with zero technologies for an FEL of 88 g/ton-mi. 

Customer 4 again wanted to avoid ATI systems, but was still willing to order some Bin VI 

aerodynamics, high-performing tires, and two large weight reduction packages, which resulted in a

compliant trailer order at an FEL of 77 g/ton-mile. 

Table 10: Example Technology Adoption Rates for Four Customers in a MY 2027 Averaging Scenario with Four 

Subfamilies

Long Dry Van Cust 1 Cust 2 Cust 3 Cust 4

0.0 Aero Bin I 0% 100%

0.1 Aero Bin II 

0.3 Aero Bin III 

0.5 Aero Bin IV 100%

0.7 Aero Bin V

1.0 Aero Bin VI 100%

1.4 Aero Bin VII 100%

1.8 Aero Bin VIII

Average Delta CdA 0.5 0.0 1.4 1.0

6.00 Baseline 0% 100% 0% 0%

5.10 TRRL 1

4.70 TRRL 2 100% 100% 100%

Average CRR 4.7 6.0 4.7 4.7

1.50 Adopt ATI 100% 100%

ATI 1.5% 0.0% 1.5% 0.0%

0 None

168 WR Package 1

556 WR Package 2

910 WR Package 3 100% 100% 100%

1315 WR Package 4 100% 100% 100%

Weight Reduction 2781 0 2225 2225

Customer CO2 (g/ton-mi) = 78 88 74 77

Customer Order (trailers) = 30 10 40 20
Example Trailer Compliance Scenarios / Docket EPA-HQ-OAR-2014-0827

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The production-weighted average for these four subfamilies came out to 77 g/ton-mi, which 

means the trailer manufacturer met the MY 2027 standard. As with the MY 2021 averaging examples, 

this example shows that averaging would allow the manufacturer to offer some trailers with fewer 

technologies. It can be seen that, in order for Customer 2 to order trailers with zero technologies, all of 

the other customers had to purchase higher performing trailer in order to make up for the undercompliance resulting from Customer 2’s order. This was possible due to the relatively small order from 

Customer 2. A manufacturer would have a difficult time complying if a customer with a larger order 

requested a minimum-technology package in MY 2027.

As shown previously in the MY 2021 averaging example, customers could order trailers with 

multiple levels of performance, but there would be fewer technology options capable of meeting the 

higher performance targets by MY 2027. We do not illustrate that example here. 

Summary of the Averaging Compliance Approach

In summary, these set of examples show how averaging can give a manufacturer the flexibility to 

meet its customers’ individual preferences. Specifically, 40 percent or more of the sales in these 

averaging examples did not meet the overall standard for this model year. In fact, 10 percent of this 

manufacturer’s sales had zero CO2-reducing technologies. This strategy could be valuable for trailer 

manufacturers that have customers willing to purchase sufficient numbers of trailers with higherperforming technologies that offset orders from customers that prefer fewer or lower-performing 

technologies. This flexibility would come with an increased compliance burden in terms of number of 

subfamilies and CO2 calculations, increased tracking of sales, and increased end-of-year reporting to the 

agencies, as well as the potential for more complex interactions with customers in sales negotiations.

All trailer manufacturers submit an end-of-year production report to EPA that summarizes their 

annual sales. Trailer manufacturers that adopt an averaging compliance approach would include a 

description of the subfamilies in their application for certification, and would submit a second end-ofyear report that describes their averaging strategy and the results for each of their subfamilies. These 

manufacturers would not need to ensure that every trailer produced throughout the year met the 

standard. However, they would benefit from keeping record throughout the year of the volume of sales 

and an estimate of the CO2 (and fuel consumption) level for each sale to ensure that under-complying 

trailer sales do not account for a majority of the overall sales for the year. Otherwise, a manufacturer 

could be in a situation where they have to make up for a large deficit at the end of the year in order to 

comply.

Final Notes

We are proposing to allow manufacturers the choice of the primary compliance program, or an 

averaging program. Every year, the trailer manufacturer would choose a compliance approach. 

Manufacturers may choose a single strategy throughout the program, or they change strategies at any 

time. Some manufacturers may wish to do averaging early to ease customers into technologies, and 

switch to the primary (non-averaging) approach in the later years when it may be more difficult to 

ensure compliance if trailers are sold with minimal technologies. Alternatively, a trailer manufacturer 

may find it easier to exclusively sell compliant trailers in the earlier years, when fewer technologies 

would be needed to meet the standard, and then convert to an averaging compliance program in the later 

years, when some customers would be reluctant to adopt the more advanced technologies.