1975-02-01

Lubricant Viscosity Effects on Passenger Car Fuel Economy 750675

As part of General Motors effort to improve fuel economy, the effects of engine and power train lubricant viscosities were investigated in passenger car tests using either high- or low- viscosity lubricants in the engine, automatic transmission, and rear axle. Fuel economy was determined in both constant speed and various driving cycle tests with the car fully warmed-up. In addition, fuel economy was determined in cold-start driving cycle tests.
Using low-viscosity lubricants instead of high-viscosity lubricants improved warmed-up fuel economy by as much as 5%, depending upon the differences in lubricant viscosity and type of driving. Cold-start fuel economy with low-viscosity lubricants was 5% greater than that with high-viscosity lubricants. With such improvements, it is concluded that significant customer fuel economy gains can be obtained by using the lowest viscosity engine and power train lubricants recommended for service. To determine if currently recommended engine oil, automatic transmission fluid, and rear axle lubricant viscosities can be reduced, extensive performance and durability testing will be required.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Members save up to 16% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:
TECHNICAL PAPER

Automotive Fuel Savings Through Selected Lubricants

750377

View Details

TECHNICAL PAPER

Engine and Transmission Lubricant Viscosity Effects on Low Temperature Cranking and Starting

690768

View Details

JOURNAL ARTICLE

Understanding MTF Additive Effects on Synchroniser Friction

2011-01-2121

View Details

X