Heavy-Duty
Engine Lubricant
Fuel Economy Assessment


Contact Information

Larry Eckhardt
Manager
Fleet & Field Evaluations
(210) 522-2980
leckhardt@swri.org

image: Additional trucks and test laps can be added to a program to improve repeatability and confidence of final results.

Additional trucks and test laps can be added to a program to improve repeatability and confidence of final results.

 

image: Automotive engines are run on specialized test stands equipped with computer control and computer data acquisition.

Automotive engines are run on specialized test stands equipped with computer control and computer data acquisition.

Using test methods currently available to the industry and two commercially available heavy-duty engine oils, Southwest Research Institute (SwRI) investigated lubricant-related fuel economy.

Fuel Economy Test Procedures

The SAE J1321 on-highway fuel economy test procedures were used in a fleet of four heavy-duty trucks. Fuel economy benefit was defined relative to CEC RL 191, the baseline candidate reference oil for the European light-duty gasoline engine fuel economy test procedure, CEC L-54-T-96 (Mercedes M111).

Fuel economy improvement values were computed from the on-highway test results. Testing the same two lubricants in stationary engine dynamometer tests using the Mercedes M111 and the ASTM Sequence VIB test procedures also served as a crosscheck.

Fuel Economy Test Results

  • Automotive engines are run on specialized test stands equipped with computer control and computer data acquisition.
  • SAE J1321, CEC M111, and ASTM Sequence VIB test procedures all ranked Lubricant A and Lubricant B in the same order for fuel economy performance.
  • The CEC M111 fuel economy test procedure may be useful for heavy-duty engine applications, primarily because of the SAE 15W-40 baseline reference oil.
  • The ASTM Sequence VIB test procedure may be useful for heavy-duty application if it is conducted in tandem with a heavy-duty lubricant of known fuel economy performance.
  • A strong linear correlation (R2 = 0.96) was found to exist between the Mercedes M111 (19 hr) and the Sequence VIB (96 hr) fuel economy results.

 

image: SAE J1321 Fuel Economy Improvement

SAE J1321 Fuel Economy Improvement

 

image: Linear relationship between Sequence VIB (96 hr) and M111 (19 hr) fuel economy

Linear relationship between Sequence VIB (96 hr) and M111 (19 hr) fuel economy


Related Terminology

fuel economy test procedure  •  engine lubricant  •  SAE J1321 test procedure  •  on-highway fuel economy  •  fuel economy improvement  •  Mercedes M111  •  ASTM Sequence VIB  •  CEC M111  •  heavy-duty engine

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Southwest Research Institute® (SwRI®), headquartered in San Antonio, Texas, is a multidisciplinary, independent, nonprofit, applied engineering and physical sciences research and development organization with 11 technical divisions.
07/05/12