Power

& Mobility

8/9/2018

Improving Military Ground Vehicle Fuel Efficiency

through the Identification of More Fuel Efficient

Gear Oils (FEGOs) – Development of a Stationary

Axle Efficiency Test Stand and Test ProcedureAllen S. Comfort

Adam BrandtSteven Thrush

DISTRIBUTION STATEMENT A. Approved for public release; distribution unlimited.

Power &

Mobility

8/9/2018 DISTRIBUTION STATEMENT A. Approved for public release; distribution unlimited.

Running Out of Fuel Is No Fun

Power &

Mobility

8/9/2018 DISTRIBUTION STATEMENT A. Approved for public release; distribution unlimited.

How Can We Reduce Fuel Usage?

• Design more efficient engines and powertrains

• Recover waste energy (e.g., regenerative braking)

• Improve aerodynamics

• Reduce weight of vehicles

• Use low rolling resistance tires

• …

How about changing your oil?

The only way to reduce fuel usage of legacy vehicles without expensive retrofitting!

Past project:

Fuel efficient engine oil: 1.5 – 4%Fuel efficient transmission fluid: 0.5 – 1%

Fuel efficient gear oil (FEGO): 1.0 – 2.0%

Synthetic Multi-Purpose Lubricant (SMPL)

Power &

MobilityAxle Efficiency Losses

8/9/2018 DISTRIBUTION STATEMENT A. Approved for public release; distribution unlimited.

Power &

Mobility

8/9/2018 DISTRIBUTION STATEMENT A. Approved for public release; distribution unlimited.

Gear Oil Nomenclature

Example:

75W - 90

Winter Grade: Acts

like a 75 grade in cold temperatures

Summer Grade: Acts

like a 90 grade in hot

temperatures

Current military standard gear oils:• 75W-90

• 80W-90• 85W-140

Power &

Mobility

8/9/2018 DISTRIBUTION STATEMENT A. Approved for public release; distribution unlimited.

Vehicle Fuel Consumption Testing

SAE J1321 Fuel Consumption Test Procedure - Type II

Power &

Mobility

8/9/2018 DISTRIBUTION STATEMENT A. Approved for public release; distribution unlimited.

Axle Efficiency – Test Stand Concept

• Lower qualification test costs

• Modular

• Excellent repeatability

• High precision and discrimination

Power &

Mobility

8/9/2018 DISTRIBUTION STATEMENT A. Approved for public release; distribution unlimited.

Completed Axle Efficiency Test Stand

Temperature Control• Two possible

procedures

1. Allow the axle to obtain its own steady-state temperature

2. Control the temperature to a set valuea. Based on vehicle data a

temperature of 175°F was chosen

Power &

Mobility

8/9/2018 DISTRIBUTION STATEMENT A. Approved for public release; distribution unlimited.

Efficiency Test Development -MTV Drive Cycle Replication

Approximate Vehicle Velocity

Pinion Input Speed (rpm)

Pinion Input

Torque

Pinion Input

Power

88.5 km/h(55 mph)

3207

141 Nm(104 lbft)

47 kW(64 hp)

56 km/h(35 mph)

2033

91 Nm(67 lbft)

19 kW(26 hp)

48 km/h(30 mph)

1723

89 Nm(66 lbft)

16 kW(22 hp)

40 km/h(25 mph)

1469

73 Nm(54 lbft)

11 kW(15 hp)

32 km/h(20 mph)

1157

61 Nm(45 lbft)

7 kW(10 hp)

24 km/h(15 mph)

86561 Nm

(45 lbft)

6 kW(7 hp)

16 km/h(10 mph)

68476 Nm

(56 lbft)

5 kW(7 hp)

8 km/h(5 mph)

294108 Nm

(80 lbft)

3 kW(5 hp) *Gear Oil Temperature: 175°F

90.00

90.50

91.00

91.50

92.00

92.50

93.00

93.50

94.00

94.50

95.00

Trans_05r Trans_10r Trans_15r Trans_20r Trans_25r Trans_30r Trans_35r Trans_55r

Eff

icie

ncy

, [%

]

Step

Average Efficiency, per Test Run

75W140 R1

75W140 R2

75W140 R3

75W140 R4

75W140 R5

80W90 R1

80W90 R2

80W90 R3

80W90 R4

80W90 R5

75W90 R4

75W90 R5

75W90 R6

75W90 R7

75W90 R8

%𝐸𝑓𝑓𝑖𝑐𝑖𝑒𝑛𝑐𝑦 =𝑃𝑜𝑤𝑒𝑟𝑂𝑢𝑡𝑃𝑜𝑤𝑒𝑟𝐼𝑛

∗ 100

Power &

Mobility

8/9/2018 DISTRIBUTION STATEMENT A. Approved for public release; distribution unlimited.

Efficiency Test Development -Efficiency Mapping

MTV Axle Efficiency Map – 80W-90 MTV Axle Efficiency Map – 75W-90 MTV Axle Efficiency Map – 75W-140

Power &

Mobility

8/9/2018 DISTRIBUTION STATEMENT A. Approved for public release; distribution unlimited.

Efficiency Test Development -Proposed Federal Test Method (FTM)

Test StepApproximate Vehicle Speed

Pinion Input Speed (rpm)

Pinion Input

Torque

Pinion Input

Power

FTM_25_45040 km/h(25 mph)

1469610 Nm

(450 lbft)94 kW

(126 hp)

FTM_35_25056 km/h(35 mph)

2033338 Nm

(250 lbft)72 kW(97 hp)

FTM_25_32540 km/h(25 mph)

1469440 Nm

(325 lbft)68 kW(91 hp)

FTM_45_17572 km/h(45 mph)

2600237 Nm

(175 lbft)65 kW(87 hp)

FTM_15_40024 km/h(15 mph)

865542 Nm

(400 lbft)49 kW(66 hp)

FTM_55_10488 km/h(55 mph)

3207141 Nm

(104 lbft)47 kW(64 hp)

FTM_35_6756 km/h(35 mph)

203391 Nm

(67 lbft)19 kW(25 hp)

FTM_25_5440 km/h(25 mph)

146973 Nm(54 lbft)

11 kW(15 hp)

FTM_15_4524 km/h(15 mph)

86561 Nm

(45 lbft)6 kW(8 hp)

FTM_5_808 km/h(5 mph)

294108 Nm(80 lbft)

3 kW(4 hp)

1

3

2

4

5

9 8 7

6

10

1

2

3

4

5

6

7

8

9

10

Power &

Mobility

8/9/2018 DISTRIBUTION STATEMENT A. Approved for public release; distribution unlimited.

Efficiency Test Development -Proposed FTM Results 75W-90 versus 80W-90

90.00

90.50

91.00

91.50

92.00

92.50

93.00

93.50

94.00

94.50

95.00

95.50

96.00

96.50

97.00

97.50

98.00

Eff

icie

ncy

, [%

]

Step

Average Efficiency, per Test Run

80W90 R1

80W90 R2

80W90 R3

80W90 R4

80W90 R5

80W90 R6

75W90 R1

75W90 R2

75W90 R3

75W90 R4

75W90 R5

75W90 R6

MTV Efficiency Results - Proposed Final Test Points 75W-90

-1.50%

-1.30%

-1.10%

-0.90%

-0.70%

-0.50%

-0.30%

-0.10%

0.10%

0.30%

0.50%

0.70%

0.90%

1.10%

1.30%

1.50%

Eff

icie

ncy

Im

pro

ve

me

nt

Test Step

75W-90 Efficiency Improvement

Power &

Mobility

8/9/2018 DISTRIBUTION STATEMENT A. Approved for public release; distribution unlimited.

Efficiency Test Development -Proposed FTM Results 75W-140 versus 80W-90

90.00

90.50

91.00

91.50

92.00

92.50

93.00

93.50

94.00

94.50

95.00

95.50

96.00

96.50

97.00

97.50

98.00

Effi

cie

ncy

, [%

]

Step

Average Efficiency, per Test Run

80W90 R1

80W90 R2

80W90 R3

80W90 R4

80W90 R5

75W140 R1

75W140 R2

75W140 R3

75W140 R4

75W140 R5

-1.50%

-1.30%

-1.10%

-0.90%

-0.70%

-0.50%

-0.30%

-0.10%

0.10%

0.30%

0.50%

0.70%

0.90%

1.10%

1.30%

1.50%

Eff

icie

ncy

Im

pro

ve

me

nt

Test Step

75W-140 Efficiency Improvement

MTV Efficiency Results - Proposed Final Test Points 75W-140

Power &

Mobility

8/9/2018 DISTRIBUTION STATEMENT A. Approved for public release; distribution unlimited.

Efficiency Test Development -Proposed FTM Results for LTV

-1.50%

-1.30%

-1.10%

-0.90%

-0.70%

-0.50%

-0.30%

-0.10%

0.10%

0.30%

0.50%

0.70%

0.90%

1.10%

1.30%

1.50%

Eff

icie

ncy

Im

pro

ve

me

nt

Test Step

75W90 - Efficiency Improvement

-1.50%

-1.30%

-1.10%

-0.90%

-0.70%

-0.50%

-0.30%

-0.10%

0.10%

0.30%

0.50%

0.70%

0.90%

1.10%

1.30%

1.50%

Effi

cie

ncy

Imp

rove

me

nt

Test Step

75W140 - Efficiency Improvement

LTV Efficiency Results - 75W-90 LTV Efficiency Results - 75W-140

2040

57

11

16

23

16 26

3

8

= Quasi-Stribeck Number (rpm/torque)

Power &

Mobility

8/9/2018 DISTRIBUTION STATEMENT A. Approved for public release; distribution unlimited.

Efficiency Test Development -Temperature Control Revisited

MTV Axle Lubricant Temperature with

Fixed Cooling Rate – 80W-90 vs. 75W-90

MTV Axle Lubricant Efficiency with Fixed

Cooling Rate – 80W-90 vs. 75W-90

Power &

Mobility

8/9/2018 DISTRIBUTION STATEMENT A. Approved for public release; distribution unlimited.

Efficiency Test Development -Temperature Control Revisited

MTV Axle Lubricant Temperature with

Fixed Cooling Rate – 80W-90 vs. 75W-140

MTV Axle Lubricant Efficiency with Fixed

Cooling Rate – 80W-90 vs. 75W-140

Power &

Mobility

8/9/2018 DISTRIBUTION STATEMENT A. Approved for public release; distribution unlimited.

Summary and Conclusion

• An axle efficiency test stand was designed and built using axles from light and medium tactical vehicles

• The test stand was used to develop efficiency maps of a standard 80W-90, and fuel efficient 75W-90, and 75W-140 gear oils

• A test procedure was developed and the efficiency results correlated well with results from vehicle fuel consumption testing

• A fuel efficient 75W-90 provided efficiency benefits over the entire range of operating conditions tested compared to 80W-90

• Investigation of efficiency and temperature response under conditions of fixed cooling rate targets demonstrated that lower power operating points require a lower operating temperature for more realistic efficiency results (e.g., 140°F vs. 175°F)

• Final step to implementation as a Federal Test Method will be to finalize a method to distill the efficiency results down to a single number (or small set) that can be used for qualification