Application of a Split Lubrication Gasoline Engine to the Screening and Understanding of Friction Modifier Behaviour
ISSN: 1946-3952, e-ISSN: 1946-3960
Published August 30, 2011 by SAE International in United States
Citation: Nattrass, S. and Davenport, A., "Application of a Split Lubrication Gasoline Engine to the Screening and Understanding of Friction Modifier Behaviour," SAE Int. J. Fuels Lubr. 5(1):511-522, 2012, https://doi.org/10.4271/2011-01-2134.
A series of viscous and surface friction modifier additives has been studied in a modified SI engine with separable valve train lubrication. From the results, it has been possible to classify the hydrodynamic or boundary lubrication nature of the observed effects for a series of lubricant additives. It is shown that the frictional benefit of a given additive depends not only on the engine operating condition but also on the engine components on which it is acting. For some additives a fuel economy benefit can switch to a disbenefit as operating regime changes and a different aspect of the additive properties becomes important. Such observations are rationalised in the context of conventional lubrication theory.