Southwest Research Institute ® San Antonio, Texas



## Technologies For MD/HD GHG & Fuel Efficiency Thomas Reinhart Dec. 10, 2014

# Agenda 1. Project Outline 2. Project Status 3. Preliminary Results 4. Preliminary Observations

2 2014

# NHTSA Project Outline

• Engine and vehicle technology simulations
• Engines:

– 15 liter long haul diesel (with 12.5 liter 5 - cylinder variant)

– 6.7 liter medium duty diesel (with 8.9 liter 8 - cylinder variant)

– 6.7 liter pickup truck diesel (with 4.5 liter 4 - cylinder variant)

– 6.2 liter V

- 8 gasoline

– 3.5 liter V

- 6 turbocharged DI gasoline

3

# Project Outline

• Vehicles:

– Class 8 tractor - trailer

– Class 6 delivery truck (box truck)

– Class 6 roll - on tow truck

– Class 2b / 3 pickup

4 2014

# Drive Cycles Used

• Class 2b / 3 (Pickup Truck)

– FTP - City, FTP - Highway (light duty certification cycles)

– US06 (Aggressive light duty certification cycle)

– SC03 (Urban cycle used for light duty A/C testing)

– WHVC (World Harmonized Vehicle Cycle, a truck cycle with urban, suburban, and highway segments)
 Not representative of 2b/3 operation, but used for comparison with MD truck results

– 65 MPH cruise
 Used for comparison with MD truck results


### • Note: A/C use was simulated on all cycles, with 

### all vehicles 5 2014

# Drive Cycles Used

• Class 6 (F - 650 and T - 270):

– CARB truck urban cycle, 55 MPH cruise, 65 MPH cruise
 Cycles used for Phase 1 GHG regulatory compliance

– WHVC (World Harmonized Vehicle Cycle, a truck cycle with urban, suburban, and highway segments)
 Used for comparison with other truck results

– CILCC (Combined International Local & Commuter Cycle)
 Delivery cycle designed with gentle accelerations and decelerations, with 6% idle time

– Parcel delivery cycle
 Represents a delivery truck operating in an urban / suburban environment, with 50% idle time 6 2014

# Drive Cycles Used

• Class 8 (T

- 700 tractor - trailer)

– CARB truck urban cycle, 55 MPH cruise, 65 MPH cruise
 Cycles used for Phase 1 GHG regulatory compliance

– WHVC (World Harmonized Vehicle Cycle, a truck cycle with urban, suburban, and highway segments)
 Used for comparison with other truck results

– NESCCAF (Northeast States Center for a Clean Air Future)
 Cycle designed to simulate a long haul duty cycle  Includes a brief urban/suburban segment and a long cruise  Includes +/

- 1% and +/

- 3% grades, 64 – 67 MPH cruise 7 2014

# Drive Cycles Used

• Note that the drive cycles selected were used for research purposes

– These cycles may not be used in the Phase 2 regulations

8 2014

# Project Status

• All simulation of individual engine technologies is complete

– 64 engine technologies evaluated

– 64 fuel maps created

• All simulation of individual vehicle technologies is complete

– 28 vehicle technology combinations evaluated

– 2,118 vehicle simulation runs completed

• Simulation of engine and vehicle technology combinations is now complete

– 32 engine technology combinations evaluated

– Several thousand vehicle simulation runs completed 9 2014

# A Note On FMEP (Engine Friction)

• In our study, we assumed that FMEP could be reduced by addressing any engine component needed for engine operation
• Examples:

– Piston / ring / liner friction

– Bearing friction

– Valve train and gear train friction

– Variable speed / displacement oil and water pumps
 On/off control of piston cooling nozzles

– Reduced power demand fuel pump

– Reduced viscosity engine oil, friction modifiers in oil
• Accessories required by the vehicle are addressed separately (A/C, power steering, air compressor, etc.) 10 2014

# Heavy Duty Long - Haul

• This category uses one base engine, the DD15

• This category uses one base vehicle, the 

### Kenworth T

- 700 aerodynamic tractor with a standard (non - aero) 53 foot box van trailer

11

# Long Haul Engine Technologies

12 2014

# Tractor - Trailer Technologies

13

## Some Preliminary HD Observations

• Engine friction reduction provides significant benefits, particularly on lightly loaded cycles
• Both downspeeding and downsizing show 1.5% to 4% benefit

– Hard to combine both, because of BMEP limits
• R245 BC provides about 3% (for reference, water based BC provides about 5 %)

– Note transient performance issues – long haul only technology
• Large Cd and Crr reductions provide large benefits
• Turbocompound didn’t work out well here. Other, smaller engines have shown better results 14 2014

## Some Preliminary HD Observations

• Increasing the number of gear ratios doesn’t help much

– Engine has good BSFC over a wide enough range to work well with the 10 - speed
• It takes big weight reductions to provide a significant fuel savings / GHG benefit (See notes)
• Road speed governors provide a big benefit, if the drive cycle has a large portion of high speed operation

– Note productivity issue
• Simulating a manual transmissions is tricky, and needs to be supported by field tests

– Fuel penalty for manual indicated by 55 MPH cycle and WHVC involve running a gear down, which causes a large penalty 15 2014

# 2019 Baseline DD15

• Uses asymmetric turbo – similar to 2014 production



## • Assume a 1% improvement from shorter combustion duration

– This can represent any incremental improvement


## • Complies with 2017 GHG requirement

– With zero margin

16 2014

# HD Engine Technology Combos

17

# HD Engine Technology Combos

18 Note: P3 Performance is relative to P2

# HD Vehicle Technology Combos

19

## Some Preliminary HD Combo Observations

• Friction reduction and downspeeding perform on the 2019 baseline similar to the original baseline

• The refrigerant - based WHR system benefits significantly from a recuperator, but the other working fluids show a smaller benefit

• Methanol, ethanol, and water working fluids give similar WHR performance

• Throwing the kitchen sink at the turbocompound engine still does not result in performance better than asymmetric turbo packages on this particular engine

– Note that turbocompound has shown a benefit on other engines 20 2014

## Some Preliminary HD Combo Observations

• Vehicle Combo Package 4 pushes into SuperTruck territory

– Combines vehicle and engine technology packages, similar to SuperTruck

– ~33% fuel savings on long haul cycles = ~50% MPG improvement

– Note that SuperTrucks have ~50% Cd reduction, vs. 25% in this study, so SuperTrucks perform even better

• Larger fuel savings are available from vehicle power demand reductions than from engine efficiency improvements

– Maximum engine potential fuel savings in this study is ~10%

21 2014

# Medium Duty Vocational

• This category uses 3 engines:

– The medium - duty ISB diesel

– A 6.2 liter port - injected V - 8

– A 3.5 liter turbocharged V - 6


### • This category uses 2 trucks:

– Ford F - 650 roll - on tow truck

– Kenworth T

- 270 delivery truck

22

# MD Diesel Technologies

23

# Boosted V

- 6 Technologies for MD

24

# V - 8 Technologies for MD

25

# MD Engine Comparison

26

# T - 270 Vehicle Technologies

27 2014

# F - 650 Vehicle Technologies

28

## Technology Sensitivity to Payload, CARB Cycle

29 2014

## Technology Sensitivity to Payload, 65 MPH Cruise

30 2014

## Some Preliminary MD Observations

• Reduced FMEP helps the diesel

– Up to 8% on low speed, light load cycles

– About 2% on high speed, high load cycles (see notes) 

### • The diesel and V

- 6 gas can provide significant benefits over the V

- 8 gas engine

– V - 6 benefit is up to 10% on lightly loaded cycles only  Reduced pumping work and friction  No V - 6 benefit at high loads

– Diesel benefit is 20 – 25% on most cycles  Biggest benefit at high loads

– Diesel suffers from tighter torque converter match on cycles with significant idle time (Parcel cycle) 31 2014

## Some Preliminary MD Observations

• Lean burn looks attractive for gasoline engines, but there are aftertreatment issues

– High exhaust temps, sulfur poisoning


### • VVA/VVL provides 3% to 4% benefit for gasoline

• EGR provides 4% to 10% benefit for gasoline

– Best at high load, where enrichment is eliminated


### • An AMT provides 3% to 4% on most cycles, but up to 10% with significant idle

– Suggests benefit for idle neutral feature on automatic
32 2014

## Some Preliminary MD Observations

• Crr reduction provides 4% to 8% benefit, similar to the long haul truck



### • Weight reduction benefit is modest (1% to 2%) across all drive cycles

• Benefit of EGR and reduced tire rolling resistance goes up with increasing payload, while benefit of cylinder deactivation declines

33 2014

# 2019 Baseline MD Engines

• ISB Diesel

– Assumed 1% benefit from shorter combustion duration
 Could represent any incremental improvement

– Assumed partial FMEP reduction
 5% at high speed and load, increasing to 17.5% at low speed, light load

– Provides 2% to 5% improvement vs. 2013 baseline, to comply with 2017 requirements


### • Gasoline engines were carried over unchanged for 2019
34 2014

# MD Diesel Engine Tech. Combos

35 2.5T+Dwnspd No EGR+5T+FMEP No EGR+5G+.5F+Dwn F+2.5T 4Cyl+EGR

# MD V - 6 Technology Combos

36

VVA + EGR P1 + Dwnspd P1 + Lean P2 - VVA

# MD V - 8 Technology Combos

37 GDI+Deac+EGR+F P1 + VVA P1 – VVA + Phasers P1 - FMEP P1 - Deac

# T - 270 Truck Technology Combos

38

Package 1 Sweeps P3 Results Are vs. P2, and P5 is vs. P3

- 20Crr+8spd+Id N+AC - 800 Lb

# F - 650 Truck Technology Combos

39

P3 Results Are vs. P2, and P5 is vs. P3

Package 1 Sweeps - 20Crr+8spd+Id N+AC - 800 Lb

# Axle Ratio and Weight Sweeps

• Sweeps were performed on axle ratio and vehicle empty weight

– For all 3 2019 baseline engines (2 gasoline and 1 diesel)

– On both medium duty trucks and on the pickup truck


### • In the interest of time, these slides are hidden

– But you are welcome to review them at your leisure

40

# Effect of Axle Ratio Sweep, Diesel

41 Baseline

# Effect of Axle Ratio Sweep, V - 6

42 Baseline

# Effect of Axle Ratio Sweep, V - 8

43

# Effect of Empty Weight, T - 270

44

## Some Preliminary MD Combo Observations

• Downspeeding helps, except on cycles with significant idle time

– Higher torque converter load hurts at idle

– An idle neutral feature can fix this issue


### • Downsizing helps with lightly loaded drive 

### cycles, but hurts on highly loaded cycles
• There is significant overall potential for gasoline engine improvement (6% to 10%)
• Potential vehicle improvement is 5% to 10%

– Less than for long haul trucks 45 2014

## Some Preliminary MD Combo Observations

• The T - 270 is more sensitive to Cd than the F - 650

– Driven by frontal area differences


### • Other technologies have a very similar effect on both trucks
• Low speed drive cycles are insensitive to axle ratio

– High speed cycles can be very sensitive


### • The baseline axle ratios appear near optimal for the diesel and V

- 6

– The V - 8 could benefit from a one step taller axle 46 2014

## Some Preliminary MD Combo Observations

• Sensitivity to vehicle empty weight is rather small



### • The V - 6 is most sensitive to weight, while the V - 8 is least sensitive

47 2014

# Class 2b / 3 Pickup Truck

• This category uses 3 engines:

– The light duty ISB diesel
 Higher power, torque, and RPM than the medium duty version

– A 6.2 liter port - injected V - 8

– A 3.5 liter turbocharged V - 6 

### • This category uses 1 truck:

– Ram 2500/3500

48

# Pickup Diesel Technologies

49

# 3.5 V - 6 Technologies in Pickup

50

# 6.2 V - 8 Technologies in Pickup

51

# Comparison of V

- 6 & Diesel to V

- 8

52

# Pickup Vehicle Technologies

53

# Pickup Vehicle Technologies

54

## Technology Payload Sensitivity, City Cycle

55

## Technology Payload Sensitivity, US06 Cycle

56

## Some Preliminary Pickup Observations

• For the diesel, friction reduction and the 4 - 

### cylinder option work better than in medium trucks

– Because of the low average load


### • Lean burn looks very good, but aftertreatment issues remain


### • EGR provides ~4% benefit for gas engines
• Downspeed helps the V - 6, and cylinder deactivation helps the V - 8

– More than in MD trucks, because of lower average load 57 2014

## Some Preliminary Pickup Observations

• On very lightly loaded cycles, the V - 6 can beat the diesel

– Low friction and pumping work, higher BMEP 

### • Accessory power reduction provides a bigger benefit than in MD

– lower average power demand


### • Vehicle technologies provide modest benefits
• When towing:

– EGR and Crr are important

– Cylinder deactivation loses benefit 58 2014

# 2019 Baseline Pickup Engines

• ISB Diesel

– Assumed 1% benefit from shorter combustion duration
 Could represent any incremental improvement

– Assumed partial FMEP reduction
 5% at high speed and load, increasing to 17.5% at low speed, light load

– Provides 2% to 5% improvement vs. 2013 baseline, to comply with 2017 requirements


### • Gasoline engines were carried over unchanged for 2019
59 2014

## Comparison of V

- 6 and Diesel To V - 8

60

# Pickup Diesel Tech. Combos

61 Dwnspd +.5T No EGR+FMEP+T No EGR+dwnspd+T 2019 + FMEP 4 - Cyl + FMEP

# Pickup V

- 6 Technology Combos

62 VVA + EGR P1 + Dwnspd P1 + Lean P2 - VVA

# Pickup V

- 8 Technology Combos

63 GDI+Deact+EGR+ FMEP P1 + VVA P1 – VVA + Phasers P1 - FMEP P1 - Deact

# Pickup Vehicle Tech. Combos

64

- 20Crr+8spd Idle Neutral - 20Crr, - 10Cd

P3 - 600LB - 40A/C

## Pickup Axle Ratio Sweep with Diesel

65

# Pickup Axle Ratio Sweep with V - 6

66

# Pickup Axle Ratio Sweep with V - 8

67

# Pickup Empty Weight Reduction

68

## Some Preliminary Pickup Combo Observations

• The 4 - cylinder provides a big benefit

– As long at heavy towing is not required


### • Gas engine improvements up to 10% (V - 6) or 12% (V - 8) appear possible

• Vehicle improvements up to 10% appear possible

69 2014

## Some Preliminary Pickup Combo Observations

• Taller axle ratios benefit fuel economy on most cycles

– Note that our baseline gas axle ratios are much shorter than those on the market. We went for 25,000 pound towing capacity, which is not currently offered with gas engines

– The pickup has more margin to use taller axles without running a gear down, except at GCW


### • As in the MD trucks, the V - 6 is most sensitive to vehicle weight reduction

70 2014

# Overall Observations

• Long haul trucks have the largest potential % fuel savings

– Given their high VMT, they can also support more investment in fuel saving technology
 Still, not all technologies will prove cost effective

– Savings of up to 33% appear feasible, although not necessarily all cost - effective


### • Medium trucks and pickups have a potential 

### for up to 20% fuel savings

– It will be a struggle to make some of these savings cost - effective 71 2014