| abstract |
A method, composition and filter for reducing the presence of sludge or varnish precursors in a lubricating oil circulating within an internal combustion engine. The lubricating oil containing sludge or varnish precursors is contacted with discrete particles of an oil insoluble, oil wettable compound having an antioxidant functional group and/or a dispersant functional group, which are capable of complexing with sludge or varnish precursors. Preferably the compounds comprise a crosslinked amine having ethylene amine functionality. |