Technologies for MD & HD GHG

Tom Reinhart

Slide Notes

Slide 12: 

Optimized Turbocompound: downsized power turbine to optimize performance at cruise, at the 

expense of excessive backpressure and reduced performance at rated.

Electric Turbocompound: power turbine drives an electrical generator, which in turn drives a motor tied 

to the crank. Makes turbine speed and engine speed independent, which tends to allow for more 

efficient power turbine operation.

No EGR: EGR system removed. Fixed geometry turbocharger. Very high engine-out NOx. Combustion 

not adjusted to reflect elimination of EGR, so actual performance is likely to be around 1% better than 

predicted.

No Turbocompound: TCPD system and its resulting backpressure removed. Fixed geometry 

turbocharger. EGR drops off at low RPM, resulting in very high engine-out NOx. 

No EGR, no Turbocompound: both systems removed, but combustion not adjusted. Very high engineout NOx.

Asymmetric Turbo: Represents 2014 production DD15 design. No Turbocompound. Uses a fixed 

geometry (with wastegate) dual entry turbo. One entry is very small, which imposes a backpressure on 

the front 3 cylinders to drive EGR flow. The rear 3 cylinders are free to run with a positive delta p, which 

reduces the pumping work required to drive EGR.

Low back pressure: exhaust aftertreatment system backpressure reduced 45%

Low intake restriction: intake system restriction reduced 50% 

Zero Charge Air Cooler restriction: CAC restriction eliminated.

Low FMEP: engine friction reduced by 10% at high speed and load, increasing to 35% at low speed, light 

load

5% Turbo Efficiency: Compressor and turbine efficiencies both increased by 5% (not 5 points: for 

example 50% to 52.5%)

No EGR, No TCPD, 5% Turbo Efficiency: tech combo with high engine-out NOx

Downspeed A: cruise RPM @ 65 MPH decreased from 1368 RPM to 1209 RPM, with an increase in the 

torque curve to maintain vehicle performance
Downspeed B: cruise RPM @ 65 MPH decreased from 1368 RPM to 1051 RPM, with a large increase in 

torque curve to retain vehicle performance

5 Cylinder Torque: downsized version of the engine with increased BMEP to maintain the original torque 

curve

5 Cylinder BMEP: downsized version of the engine with constant BMEP (reduced power and torque)

Water Bottoming Cycle: water-based waste heat recovery system

R245 Bottoming Cycle: refrigerant based waste heat recovery system with no recuperator
Slide 13:

A/C – 40%: Air conditioner power demand reduced from 1.5 kW to 900 watts, a 600 watt reduction. Can 

represent any accessory power demand reduction.

Cd – 25%: Aero drag coefficient reduced 25%

Crr – 30%: Tire rolling resistance reduced 30%

Weight – 6.5%: Vehicle empty weight reduced 6.5% (2,200 pounds or 1,000 kg)

Weight – 13%: Vehicle empty weight reduced 13% (4,400 pounds or 2,000 kg)

Chassis Friction – 20%: Chassis friction (axles, driveline, wheel bearings) reduced 20%

6X2 Axles: Tandem drive axles replaced with a single drive axle and a tag (undriven) axle

Vmax: Simulates road speed governor (vehicle speed control) setting reduction

18-speed AMT: replaces standard 10-speed AMT

10-speed manual: replaces standard 10-speed AMT. Assumption is that with the manual, upshift speeds 

are increased by 200 RPM, and downshift speeds are increased by 100 RPM compared to the AMT. 
Slide 15:

In our analysis, we always keep the payload constant when changing empty vehicle weight. Since 

vehicle fuel consumption is relatively insensitive to small percentage changes in vehicle weight, the fuel 

consumption impact is small. However, if the vehicle is being operated at the maximum legal weight 

(grossed-out), then a vehicle weight reduction can be taken advantage of by a payload increase. In this 

situation, fuel consumption remains constant, but freight efficiency is improved, because more tons of 

freight get moved for a given fuel consumption.

The Phase 1 regulations treat a weight reduction as follows: 2/3 of the reduction is taken to reduce the 

test weight of the truck (providing a slight fuel consumption benefit), and 1/3 of the weight reduction 

goes to increased payload (which improves freight efficiency without changing fuel consumption). This 

1/3 to 2/3 split recognizes the fact that about 1/3 of trucks gross out, while the majority of trucks cube 

out.

In the field, it is common for carriers who routinely run at gross (tankers, bulk haulers, steel haulers, 

etc.) to pay extra for weight reduction features such as aluminum wheels. In some cases, carriers who 

run at gross will accept a downsized engine (and the durability penalty of a smaller engine) in exchange 

for the opportunity to carry more payload. 
Slide 18:

2012 Base: compares original DD15 with 2019 baseline

P1: 2019 baseline + friction reduction of 10% at high speed/load, increasing to 35% at low speed, light 

load

P2: 2019 baseline + Downspeed B (1051 RMP @ 65 MPH) + 50% of P1 friction reduction

P3: P2 + water based WHR system, no recuperator

P3a: P2 + R245 based WHR system, no recuperator

P3b: P2 + R245 based WHR system, with recuperator

P3c: P2 + Methanol based WHR system, no recuperator

P3d: P2 + Methanol based WHR system, with recuperator

P3e: P2 + Ethanol based WHR system, no recuperator

P3f: P2 + Ethanol based WHR system, with recuperator

P4: No EGR, standard fixed geometry turbo (not asymmetric) + full friction reduction (10% to 35%). High 

engine-out NOx.

P5: Turbocompound with fixed geometry turbo (like 2012 engine) + reduced intake, CAC, and exhaust 

restrictions + partial friction reduction (5% - 17.5%) + Downspeed B (1051 RPM @ 65 MPH) + 1%

combustion improvement (like 2019 baseline) 

Slide 19:

P1 includes a 3% (1000 pound) weight reduction

P2 includes a 6% (2000 pound) weight reduction 

P4 uses engine combo P2 for CARB and WHVC cycles, and engine combo P3b (R245 + recuperator) for 55 

MPH, 65 MPH, and NESCCAF cycles (Assume that WHR does not contribute on transient cycles) 
Slide 23:

Low Back Pres. = Reduced exhaust back pressure by 50% from 24 to 12 kPa.

Low FMEP = Assumed reduction in FMEP of 10% at high speed and load, increasing to 35% at low speed 

and light load.

No EGR = EGR system removed, and combustion duration shortened to reflect the loss of EGR.

5% Turbo Eff = Both turbine and compressor efficiency maps are scaled up by 5% (not 5 points). For 

example 50% efficiency goes to 52.5% efficiency. 

Slide 24:

VVA/VVL = Full authority variable valve lift, duration, and timing

Cyl Deact. = 3 cylinders deactivated at light loads to reduce pumping losses

Lean GDI = stratified lean combustion at low BMEP, lean at moderate BMEP

Stoich EGR = engine retains stoichiometric combustion, but adds cooled EGR to increase effective 

Octane value of air/fuel mixture, and to reduce pumping work.

EGR + Dwnspd = Combination of stoichiometric EGR and downspeeding from a rated speed of 6,000 

RPM to 4,500 RPM. The torque curve is increased to maintain vehicle performance.

Low FMEP = FMEP reduced by 10% across the speed / load range

5% Turbo Eff = Both turbine and compressor efficiency maps are scaled up by 5% (not 5 points). For 

example 50% efficiency goes to 52.5% efficiency. 

Slide 25:

GDI = Conversion from port fuel injection to GDI. Includes increased compression ratio and higher fuel 

pump parasitic power.

Lean GDI = stratified lean combustion at low BMEP, lean combustion at moderate BMEP

VVA/VVL = Full authority variable valve lift, duration, and timing

Cyl Deact. = 4 cylinders deactivated at light loads to reduce pumping losses

Stoich EGR = engine retains stoichiometric combustion, but adds cooled EGR to increase effective 

Octane value of air/fuel mixture, and to reduce pumping work.

Low FMEP = FMEP reduced by 10% across the speed / load range
Slide 26:

The Parcel cycle has significant idle time (50% of total time), which penalizes the diesel with its tighter 

torque converter.

CILCC cycle involves very gentle accelerations and decelerations, which favors the V-6 engine with its 

lower friction and pumping work due to small displacement. 

Slide 27:

A/C -40% = Air conditioner power demand reduced from 1,500 watts to 900 watts. Can represent any 

accessory power demand reduction.

CD – 15% = Aerodynamic drag coefficient reduced by 15%

Crr – 30% = Tire rolling resistance reduced by 30%

8-spd Auto = An 8-speed automatic transmission with somewhat higher mechanical efficiency replaces 

the baseline 5-speed automatic

6-spd AMT = A 6-speed AMT replaces the baseline 5-speed automatic. Benefit is great on the Parcel 

cycle, which involves a lot of idle time and torque converter load at idle. Benefit is also large on the 

CILCC cycle, which has very gradual accelerations. Note that AMT transmissions will have slower 

acceleration times and poor driveability compared to automatic transmissions, when the vehicle 

operates in transient conditions.

10-spd AMT = 10-speed AMT replaces the baseline 5-speed automatic. Slightly lower mechanical 

efficiency than the 6-speed AMT, but better than the automatics. Compare to 6-spd AMT to see the 

effect of number of gears.

Wght – 1100 lb. = Empty vehicle weight reduced by 1,100 pounds (500 kg)

Chassis Fr -30% = Axle, wheel bearing, and driveline friction reduced by 30% 
Slide 28:

A/C -40% = Air conditioner power demand reduced from 1,500 watts to 900 watts. Can represent any 

accessory power demand reduction.

CD – 10% = Aerodynamic drag coefficient reduced by 10%. There is less scope for Cd reduction on the F650 than on the T-270.

Crr – 30% = Tire rolling resistance reduced by 30%

8-spd Auto = An 8-speed automatic transmission with somewhat higher mechanical efficiency replaces 

the baseline 5-speed automatic

6-spd AMT = A 6-speed AMT replaces the baseline 5-speed automatic. Benefit is great on the Parcel 

cycle, which involves a lot of idle time and torque converter load at idle. The benefit is also large on the 

CILCC cycle, which has very gentle accelerations. Note that AMT transmissions will have slower 

acceleration times and poor driveability compared to automatic transmissions, when driving in transient 

conditions. The drivability issue with an AMT comes from the frequent power interruptions that are 

inherent in any single clutch automated manual transmission.

10-spd AMT = 10-speed AMT replaces the baseline 5-speed automatic. Slightly lower mechanical 

efficiency than the 6-speed AMT, but better than the automatics. Compare to 6-spd AMT to see the 

effect of number of gears.

Wght – 1100 lb. = Empty vehicle weight reduced by 1,100 pounds

Chassis Fr -30% = Axle, wheel bearing, and driveline friction reduced by 30% 

Slide 31:

The FMEP assumptions for the diesel engine are:

10% reduction at high speeds and loads, increasing to 35% reduction at low speed, light load. 

We defined engine friction (and thus FMEP) to include everything it takes to make the engine run. Thus, 

FMEP includes cylinder kit friction, valve train friction, bearing friction, water and oil pump power 

demand (and thus the effects of things like on/off piston cooling nozzles), and fuel pump power 

demand. Accessories required by the vehicle (such as the power steering pump, air conditioning 

compressor, air compressor, and cooling fan) are NOT included in FMEP. 
Slide 32:

Note that the current trend towards integrated exhaust manifolds (manifold included in the cylinder 

head casting) on light duty engines has the effect of allowing reduced enrichment at high load. This is 

because the water jacket cools the exhaust gas. This technology has not been evaluated in this project.

Note that vehicle acceleration and driving comfort suffer with an AMT, compared to an automatic. The 

trade-off is better efficiency. 

Slide 34:

The improvement of the diesel is a little higher than needed on low speed, light load drive cycles. 

However, on more highly loaded cycles, the total benefit is close to the 3% target for 2017. 

Slide 35:

P1 = 2019 Baseline + 2.5% improvement in turbo compressor and turbine efficiencies + Downspeed from 

2,500 RPM to 2,200 RPM. The downspeed engines (P1 and P3) suffer from a penalty on the Parcel cycle 

due to the tighter torque converter match that is required for a lower speed, higher torque engine. This 

results in higher idle fuel consumption.

P2 = EGR removed, 5% improvement in turbo compressor and turbine efficiencies, and the full FMEP 

reduction (10% at high speed/load, going to 35% at low speed/load). This is a high NOx option.

P3 = EGR removed, 5% improvement in turbo compressor and turbine efficiencies, the partial FMEP 

reduction (5% to 17.5%), and downspeed from 2,500 RPM to 2,200 RPM.

P4 = The 2019 baseline engine + 10% to 35% FMEP reduction (an increment of 5% to 17.5% over the 

2019 baseline) and a 2.5% improvement in turbo compressor and turbine efficiencies.

P5 = A 4-cylinder version with the pickup truck torque curve (3,000 RPM rated speed) and EGR across 

the full speed/load range to maintain NOx control. The higher rated speed partly makes up for the 

lower power and torque of the 4-cylinder version.
Slide 36:

P1 = Full authority variable valve lift, timing, and duration (VVA / VVL) + Stoichiometric EGR

P2 = P1 + Downspeed from 6,000 RPM to 4,500 RPM. The downspeed engines (P2 and P4) suffer from a 

penalty on the Parcel cycle due to the tighter torque converter match that is required for a lower speed, 

higher torque engine. This results in higher idle fuel consumption.

P3 = P1 + Lean Combustion from light to moderate load

P4 = Stoichiometric EGR + Downspeed from 6,000 RPM to 4,500 RPM (P2 minus VVA/VVL)

Note that downspeed engines suffer a fuel consumption penalty at idle due to the tighter torque 

converter match. This affects Parcel cycle performance. 

Slide 37:

P1 = GDI + Cylinder deactivation + Stoichiometric EGR + 10% FMEP reduction at all speeds and loads

P2 = P1 + full authority variable valve timing, lift, and duration (VVA / VVL)

P4 = GDI + 2 cam phasers (the base engine has one) + stoichiometric EGR + 10% FMEP reduction (P1 

with 2 cam phasers in place of cylinder deactivation)

P5 = P1 without the FMEP reduction

P7 = P1 without the cylinder deactivation

Note: there is no P3 or P6. It’s a long story... 
Slide 38:

Cd 5%, Cd 10%, Cd 15% = Package 1 sweep of aerodynamic drag coefficient

Crr 10%, Crr 20%, Crr 30% = Package 1 sweep of tire rolling resistance

20% Crr, 8- = Package 2, which has a 20% reduction in tire rolling resistance, and an 8-speed automatic 

with somewhat higher mechanical efficiency in place of the 5-speed baseline

Idle Neutral = Package 3. Adds an idle neutral feature on the 8-speed automatic to Package 2. P3 

results are compared to Package 2 rather than to the base engine, so only the effect of idle neutral is 

shown.

20% Crr, AMT = Package 4 with a 20% reduction in tire rolling resistance and a 6-speed AMT in place of 

the baseline 5-speed automatic. Note that the AMT will have slower acceleration times and poor driver 

comfort compared to automatic transmissions, when driven in transient operation.

Package 5 = 20% tire rolling resistance reduction + 8-speed automatic + idle neutral feature + 600 watt 

A/C power demand reduction + 800 lb. empty weight reduction. These results are shown compared to 

Package 3 (and thus are the incremental benefit of the A/C power reduction and the empty weight 

reduction). 

Slide 39:

Cd 5%, Cd 10%, Cd 15% = Package 1 sweep of aerodynamic drag coefficient

Crr 10%, Crr 20%, Crr 30% = Package 1 sweep of tire rolling resistance

20% Crr, 8- = Package 2, which includes a 20% reduction in tire rolling resistance, and an 8-speed 

automatic with somewhat higher mechanical efficiency in place of the 5-speed baseline

Idle Neutral = Package 3. Adds an idle neutral feature on the 8-speed automatic to Package 2. P3 

results are compared to Package 2 rather than to the base engine, so only the effect of idle neutral is 

shown.

20% Crr, AMT = Package 4 with a 20% reduction in tire rolling resistance and a 6-speed AMT in place of 

the baseline 5-speed automatic. Note that the AMT will have slower acceleration times and poor 

driveability compared to automatic transmissions in transient operation.

Package 5 = 20% tire rolling resistance reduction + 8-speed automatic + idle neutral feature + 600 watt 

A/C power demand reduction + 800 lb. empty weight reduction. These results are shown compared to 

Package 3 (and thus are the incremental benefit of the A/C power reduction and the empty weight 

reduction). 

Slide 41:

The 4.11 ratio causes a drop to 7th gear at 55 and 65 MPH. 
Slide 42:

The 7.50 axle ratio causes a drop to 7th gear at 65 MPH. The 6.89 axle ratio causes a drop to 7th gear at 

55 MPH. 

Slide 43:

The 6.17 axle ratio causes a drop to 7th gear for both 55 and 65 MPH. 

Slide 46:

Gear bound configurations are common for on/off road applications like cement mixers and dump 

trucks. This means that maximum vehicle speed is limited by the engine governor. This is done to get a 

low enough axle ratio for maneuvering off-road in difficult conditions. Gear bound configurations have 

a very large fuel economy penalty when driven at high speed. 

Slide 49:

ALVW refers to running at a test weight that is 50% of the maximum in-bed payload, but with no trailer.

5% Turbo Eff = Both turbine and compressor efficiency maps are scaled up by 5% (not 5 points). For 

example 50% efficiency goes to 52.5% efficiency.

Low FMEP = Assumed reduction in FMEP of 10% at high speed and load, increasing to 35% at low speed 

and light load.

Low Back Pres. = Reduced exhaust back pressure by 50% from 24 to 12 kPa.

No EGR = EGR system removed, and combustion duration shortened to reflect the loss of EGR.

4-Cylinder = Downsized engine with the same BMEP as the original. Power and torque are reduced by 

33.3% 
Slide 50:

ALVW refers to running at a test weight that is 50% of the maximum in-bed payload, but with no trailer.

VVA/VVL = Full authority variable valve lift, duration, and timing

Cyl Deact. = 3 cylinders deactivated at light loads to reduce pumping losses

Lean GDI = stratified lean combustion at low BMEP, lean at moderate BMEP

Stoich EGR = engine retains stoichiometric combustion, but adds cooled EGR to increase effective 

Octane value of air/fuel mixture, and to reduce pumping work.

EGR + Dwnspd = Combination of stoichiometric EGR and downspeeding from a rated speed of 6,000 

RPM to 4,500 RPM. The torque curve is increased to maintain vehicle performance.

Low FMEP = FMEP reduced by 10% across the speed / load range

5% Turbo Eff = Both turbine and compressor efficiency maps are scaled up by 5% (not 5 points). For 

example 50% efficiency goes to 52.5% efficiency. 

Base ISB = Comparison of base 3.5 V-6 to the baseline ISB engine

Slide 51:

GDI = Conversion from port fuel injection to GDI. Includes increased compression ratio and higher fuel 

pump parasitic power.

Lean GDI = stratified lean combustion at low BMEP, lean combustion at moderate BMEP

VVA/VVL = Full authority variable valve lift, duration, and timing

Cyl Deact. = 4 cylinders deactivated at light loads to reduce pumping losses

Stoich EGR = engine retains stoichiometric combustion, but adds cooled EGR to increase effective 

Octane value of air/fuel mixture, and to reduce pumping work.

Low FMEP = FMEP reduced by 10% across the speed / load range

Base ISB compares the performance of the base V-8 to the base diesel.

Slide 52:

The V-6 looks really good here, but remember: except for the US06 cycle and the 65 MPH cycle, these 

cycles involve relatively light loads. The V-6’s advantage shrinks as average power demand increases. 

Compare this slide to the T-270 engine comparison. 
Slide 53:

A/C -40% = Air conditioner power demand reduced from 1,500 watts to 900 watts. Can represent any 

accessory power demand reduction.

CD – 10% = Aerodynamic drag coefficient reduced by 10%

Crr – 30% = Tire rolling resistance reduced by 30%

8-spd Auto = An 8-speed automatic transmission with somewhat higher mechanical efficiency replaces 

the baseline 5-speed automatic

Wght – 500 lb. = Empty vehicle weight reduced by 500 pounds

Chassis Fr -30% = Axle, wheel bearing, and driveline friction reduced by 30%

Slide 54:

ALVW = 50% of bed payload, no trailer

A/C -40% = Air conditioner power demand reduced from 1,500 watts to 900 watts. Can represent any 

accessory power demand reduction.

CD – 10% = Aerodynamic drag coefficient reduced by 10%. 

Crr – 30% = Tire rolling resistance reduced by 30%

8-spd Auto = An 8-speed automatic transmission with somewhat higher mechanical efficiency replaces 

the baseline 5-speed automatic

Wght – 500 lb. = Empty vehicle weight reduced by 500 pounds

Chassis Fr -30% = Axle, wheel bearing, and driveline friction reduced by 30% 

Slide 55:

ALVW = 50% of bed payload, no trailer

GCW = Total vehicle weight of 25,000 pounds, with trailer, and with aero penalty for trailer

The 4-cylinder version and cylinder deactivation lose benefit as payload increases. EGR and rolling 

resistance reduction get better as payload increases. 
Slide 56:

ALVW = 50% of bed payload, no trailer

GCW = Total vehicle weight of 25,000 pounds, with trailer, and with aero penalty for trailer

The 4-cylinder version, Cd reduction, and cylinder deactivation lose benefit as payload increases. EGR 

and EGR + downspeed gain performance dramatically as payload increases, because they enable the 

engine to avoid enrichment. The 4-cylindere also shows an improved benefit at high payload, but this is 

because it falls far off the drive cycle (in other words, the vehicle does not drive as far or as fast with the 

4-cylinder, so this is a false economy). The benefit of rolling resistance reduction get better as payload 

increases. 

Slide 60:

The V-6 does nearly as well as the diesel on the lightly loaded FTP-City and WHVC cycles. 

Slide 61:

Because friction makes a big difference at part load, we overshot our 3% improvement target for the 

2019 baseline engine.

P1 = 2019 baseline + downspeed from 3,000 to 2,500 RPM (with increased torque to maintain 

performance) + 2.5% increase in turbo compressor and turbine efficiency

P2 = No EGR (with faster combustion) + full friction reduction (5% at high speed/load, 17.5% at low 

speed/light load compared to 2019 baseline) + 5% increase in turbo compressor and turbine efficiency. 

High NOx package.

P3 = No EGR (with faster combustion) + downspeed from 3,000 RPM to 2,500 RPM with torque increase 

+ 2019 baseline friction + 5% turbo compressor and turbine efficiency improvement

P4 = 2019 baseline + remaining friction reduction (5% at high speed/load up to 17.5% at low speed/load)

P5 = 4-cylinder with 1% combustion improvement + full friction reduction (10% at high speed/load up to 

35% at low speed/load)
Slide 62:

ALVW = 50% of bed payload, no trailer

P1 = Full authority variable valve lift, timing, and duration (VVA / VVL) + Stoichiometric EGR

P2 = P1 + Downspeed from 6,000 RPM to 4,500 RPM. The downspeed engines (P2 and P4) suffer from a 

penalty on the Parcel cycle due to the tighter torque converter match that is required for a lower speed, 

higher torque engine. This results in higher idle fuel consumption.

P3 = P1 + Lean Combustion from light to moderate load. Aftertreatment issues.

P4 = Stoichiometric EGR + Downspeed from 6,000 RPM to 4,500 RPM (P2 minus VVA/VVL)

ISB 2019 = Baseline 2019 ISB diesel

Note that downspeed engines suffer a fuel consumption penalty at idle due to the tighter torque 

converter match. This does not show up in the cycles here. 

Slide 63:

P1 = GDI + Cylinder deactivation + Stoichiometric EGR + 10% FMEP reduction at all speeds and loads

P2 = P1 + full authority variable valve timing, lift, and duration (VVA / VVL)

P4 = GDI + 2 cam phasers (the base engine has one) + stoichiometric EGR + 10% FMEP reduction (P1 

with 2 cam phasers in place of cylinder deactivation)

P5 = P1 without the FMEP reduction

P7 = P1 without the cylinder deactivation

ISB 2019 = Baseline 2019 ISB diesel

Note: there is no P3 or P6. It’s a long story... 
Slide 64:

P1 Cd 5%, Cd 10% = Package 1 sweep of aerodynamic drag coefficient

P1 Crr 10%, Crr 20%, Crr 30% = Package 1 sweep of tire rolling resistance

P2 ISB = Package 2, which includes a 20% reduction in tire rolling resistance, and an 8-speed automatic 

with somewhat higher mechanical efficiency in place of the 6-speed baseline

P3 vs. P2 = Package 3. Adds an idle neutral feature on the 8-speed automatic to Package 2. P3 results 

are compared to Package 2 rather than to the base engine, so only the effect of idle neutral is shown.

P4 = Package 4 with a 10% reduction in Cd and a 30% reduction in tire rolling resistance

P5 vs. P3 = P3 + 600 pound weight reduction + 40% A/C power demand reduction (600 watts). Results 

compared to P3. 

Slide 68:

For this analysis, the vehicle payload was held constant as empty weight was reduced. Thus, the test 

weights went down by 300, 600, and 900 pounds for each simulation.