Lubricating Oil Properties Affecting Fuel Economy in Diesel Engines

This paper summarizes the study of the effects of oil formulation on fuel consumption using Japanese diesel engines and vehicles. Several test techniques are described for screening fuel-efficient diesel engine oils. A diesel engine oil formulated with the optimized combination of detergent-inhibitor package and friction modifier (borate), and multigraded to 10W-30, proved to exhibit the maximum fuel economy and to pass requirements for CD quality. The improvements demonstrated in dynamometer engine tests have been confirmed in extensive field testing.