EPA-SwRI Update

• Testing Plan for Alternative Approach at SwRI

– Cummins ISB 300hp rating (24 points)

– Cummins ISB 200hp rating (24 points)

– Navistar N13 455hp rating (27 points)

– N13 engine with 365hp rating (27 points)

– Ford 6.8 liter gasoline engine (optional – depending on 

funding)

DRAFT & DELIBERATIVE 1
ISB Engine Platform

24 points Mapping Points

DRAFT & DELIBERATIVE 2

Config

Number

31001 31002 31003 31004 31005 31006 31007 31008

Cycles ARB, 55, 65 ARB, 55, 65 ARB, 55, 65 ARB, 55, 65 ARB, 55, 65 ARB, 55, 65 ARB, 55, 65 ARB, 55, 65

Mass (kg) 7,257 11,408 7,257 11,408 7,257 11,408 7,257 11,408

C dA 5.4 5.4 5.4 5.4 5.4 5.4 5.4 5.4

Tire C r r (kg/ton) 6.4 7.7 6.4 7.7 6.4 7.7 6.4 7.7

Tire Radius (m) 0.426 0.426 0.426 0.426 0.426 0.426 0.426 0.426

Rotating Inertia (kg) 454 454 454 454 454 454 454 454

Axle Gear Efficiency (%) 95.5 95.5 95.5 95.5 95.5 95.5 95.5 95.5

Accessory Power (W) 1300 1300 1300 1300 1300 1300 1300 1300

Engine speed @ 65 mph Speed A Speed A Speed B Speed B Speed C Speed C Max 1065 

test speed

Max 1065 

test speed

Trans 6-spd AT 6-spd AT 6-spd AT 6-spd AT 6-spd AT 6-spd AT 6-spd AT 6-spd AT

Top Gear Ratio 0.61 0.61 0.61 0.61 0.61 0.61 0.61 0.61

Axle ratio 4.16 4.16 5.07 5.07 5.98 5.98 6.62 6.62

Target engine speed @ 

65 mph

1653 1653 2014 2014 2375 2375 2630 2630

Actual engine speed @ 

65 mph

1653 1653 2014 2014 2375 2375 2630 2630
Six Additional Test Points

DRAFT & DELIBERATIVE 3

Config

Number

31009 31010 31011 31012 31013 31014

Cycles ARB, 55, 65 ARB, 55, 65 ARB, 55, 65 ARB, 55, 65 ARB, 55, 65 ARB, 55, 65

Mass (kg) 11,408 7,257 7,257 7,257 7,257 7,257

C dA 5.4 5.4 5.4 5.4 5.4 5.4

Tire C r r (kg/ton) 6.4 7.7 6.4 7.7 6.4 7.7

Tire Radius (m) 0.426 0.426 0.426 0.426 0.426 0.426

Rotating Inertia (kg) 454 454 454 454 454 454

Axle Gear Efficiency (%) 95.5 95.5 95.5 95.5 95.5 95.5

Accessory Power (W) 1300 1300 1300 1300 1300 1300

Trans 6-spd AT 6-spd AT 6-spd AT 6-spd AT 6-spd AT 6-spd AT

Top Gear Ratio 0.61 0.61 0.61 0.61 0.61 0.61

Axle ratio 5.57 4.63 3.70 3.70 3.42 3.42

Actual engine speed @ 

65 mph

2213 1840 1470 1470 1359 1359
Mapping Points for ARB Cycle

DRAFT & DELIBERATIVE 4

1

2

3

4

5

6

7

8

3.00

3.50

4.00

4.50

5.00

60.0 65.0 70.0 75.0 80.0 85.0

kW-hr

SN/SV

Interp/Extrap Points (Test Cell Data) Map Points (Test Cell Data)
Interpolation/Extrapolation (ARB)

DRAFT & DELIBERATIVE 5

Test Points Error

Config gfuel/kW-hri gfuel/kW-hri %

31001 278.56 278.56 0.00%

31002 254.63 254.63 0.00%

31003 286.69 286.69 0.00%

31004 254.15 254.15 0.00%

31005 297.42 297.42 0.00%

31006 265.18 265.18 0.00%

31007 301.34 301.34 0.00%

31008 268.59 268.59 0.00%

31009 267.15 264.31 -1.06%

31010 271.54 236.44 -12.93%

31011 269.57 263.45 -2.27%

31012 268.81 244.50 -9.04%

31013 265.09 236.70 -10.71%

31014 260.74 257.97 -1.06%

Test Cell Data
Regression Approach

• Model 1

– Global Regression as function of N/V and N/V*W

• Model 2

– Global Regression as function of N/V, N/V^2, and 

N/V*W

DRAFT & DELIBERATIVE 6
Regression Approach (ARB)

DRAFT & DELIBERATIVE 7

Model Predict Error Model Predict Error

Config gfuel/kW-hrigfuel/kW-hri % gfuel/kW-hri %

31001 278.56 280.08 0.54% 280.10 0.55%

31002 254.63 253.12 -0.59% 252.93 -0.67%

31003 286.69 283.73 -1.03% 283.58 -1.09%

31004 254.15 257.25 1.22% 256.95 1.10%

31005 297.42 298.26 0.29% 297.90 0.16%

31006 265.18 263.94 -0.47% 263.63 -0.58%

31007 301.34 301.37 0.01% 301.19 -0.05%

31008 268.59 268.53 -0.02% 268.52 -0.03%

31009 267.15 264.68 -0.93% 264.31 -1.06%

31010 271.54 276.41 1.79% 276.45 1.81%

31011 269.57 271.69 0.79% 272.30 1.01%

31012 268.81 270.59 0.66% 271.17 0.88%

31013 265.09 265.41 0.12% 266.51 0.53%

31014 260.74 267.42 2.56% 268.46 2.96%

Test Cell Data

MODEL 1 MODEL 2
Mapping Points for 55mph Cycle

DRAFT & DELIBERATIVE 8

14.50

15.00

15.50

16.00

16.50

17.00

17.50

18.00

0.0 10.0 20.0 30.0 40.0 50.0

kW-hr

SN/SV

Interp/Extrap Points (Test Cell Data) Map Points (Test Cell Data)
Interpolation/Extrapolation (55mph)

DRAFT & DELIBERATIVE 9

Test Points Error

Config gfuel/kW-hri

gfuel/kW-hri %

31001 217.12 217.12 0.00%

31002 214.50 214.50 0.00%

31003 224.30 224.30 0.00%

31004 218.83 218.83 0.00%

31005 235.57 235.57 0.00%

31006 228.19 228.19 0.00%

31007 251.81 251.81 0.00%

31008 240.08 240.08 0.00%

31009 224.93 226.69 0.78%

31010 217.60 220.07 1.14%

31011 217.91 217.12 -0.36%

31012 217.28 216.59 -0.32%

31013 218.94 217.12 -0.83%

31014 216.29 216.89 0.28%

Test Cell Data
Regression Approach (55mph)

DRAFT & DELIBERATIVE 10

Model Predict Error Model Predict Error

Config gfuel/kW-hrigfuel/kW-hri % gfuel/kW-hri %

31001 217.12 215.68 -0.66% 218.65 0.70%

31002 214.50 211.08 -1.59% 213.33 -0.55%

31003 224.30 227.42 1.39% 224.20 -0.04%

31004 218.83 220.65 0.83% 217.52 -0.60%

31005 235.57 239.01 1.46% 236.75 0.50%

31006 228.19 231.08 1.27% 228.93 0.32%

31007 251.81 247.16 -1.85% 249.87 -0.77%

31008 240.08 238.36 -0.72% 241.19 0.46%

31009 224.93 229.11 1.86% 225.60 0.30%

31010 217.60 220.32 1.25% 219.21 0.74%

31011 217.91 211.30 -3.03% 218.40 0.23%

31012 217.28 210.20 -3.26% 217.27 -0.01%

31013 218.94 207.77 -5.10% 219.19 0.12%

31014 216.29 206.99 -4.30% 218.37 0.97%

Test Cell Data

MODEL 1 MODEL 2
Mapping Points for 65mph Cycle

DRAFT & DELIBERATIVE 11

18.50

19.00

19.50

20.00

20.50

21.00

21.50

22.00

22.50

0.0 10.0 20.0 30.0 40.0 50.0

kW-hr

SN/SV

Interp/Extrap Points (Test Cell Data) Map Points (Test Cell Data)
Interpolation/Extrapolation (65mph)

DRAFT & DELIBERATIVE 12

Test Points Error

Config gfuel/kW-hri

gfuel/kW-hri %

31001 209.63 209.63 0.00%

31002 208.43 208.43 0.00%

31003 217.93 217.93 0.00%

31004 215.78 215.78 0.00%

31005 231.98 231.98 0.00%

31006 229.29 229.29 0.00%

31007 248.99 248.99 0.00%

31008 243.43 243.43 0.00%

31009 224.31 224.18 -0.06%

31010 211.22 213.61 1.13%

31011 209.02 209.63 0.29%

31012 209.17 209.40 0.11%

31013 211.26 209.63 -0.77%

31014 211.20 209.63 -0.75%

Test Cell Data
Regression Approach (65mph)

DRAFT & DELIBERATIVE 13

Model Predict Error Model Predict Error

Config gfuel/kW-hri gfuel/kW-hri % gfuel/kW-hri %

31001 209.63 207.47 -1.03% 210.22 0.28%

31002 208.43 205.33 -1.49% 208.12 -0.15%

31003 217.93 221.37 1.58% 217.87 -0.03%

31004 215.78 218.39 1.21% 214.96 -0.38%

31005 231.98 235.23 1.40% 232.90 0.40%

31006 229.29 231.72 1.06% 229.48 0.08%

31007 248.99 244.94 -1.63% 247.86 -0.45%

31008 243.43 241.06 -0.98% 244.08 0.26%

31009 224.31 226.90 1.16% 223.18 -0.50%

31010 211.22 214.04 1.34% 212.66 0.68%

31011 209.02 200.49 -4.08% 209.21 0.09%

31012 209.17 200.02 -4.37% 208.75 -0.20%

31013 211.26 196.46 -7.01% 209.73 -0.73%

31014 211.20 196.11 -7.14% 209.39 -0.86%

Test Cell Data

MODEL 1 MODEL 2