| abstract |
The present invention relates to friction reducers for use in lubricating oil compositions comprising a particular group of amorphous polymers such as aromatics, esters, narrow mixtures of base oils and / or amorphous olefin copolymers. These compositions can provide the benefit of a substantial reduction in coefficient of friction and improved fuel economy when mixed with lubricating oils, without detrimental effects such as instability, undesirably high viscosity and deposits. Is possible. In one aspect of the invention, pentaerythritol ester and optionally triol ester are added to the lubricating oil composition to provide reduced friction and improved fuel economy. In a second embodiment of the present invention, similar results are obtained by adding a hydrocarbyl aromatic compound to a lubricating oil composition containing one or more Group II base oils and Group III base oils. In a third aspect, the present invention relates to a lubricating oil composition comprising an amorphous olefin copolymer and one or more of a Group II base oil and a Group III base oil. In one embodiment, the third aspect also includes one or more hydrocarbyl aromatic compounds and polyol esters as part of the composition. In a fourth embodiment, a moderate concentration of hydrocarbyl aromatic is used in a lubricating oil composition comprising a paraffinic base oil and preferably a boronated polyisobutenyl succinimide ashless dispersant. |