Oil soluble polyethers in automotive crankcase lubricants

The evaluation of oil soluble polyethers (OSPs) in fully and semi-synthetic automotive crankcase lubricants is described. Parameters including viscosity, additive compatibility, lubricity/wear performance, oxidative stability, and piston cleanliness are assessed. It is possible to formulate OSP-containing lubricants with lower VI improver treatment level, superior viscometric properties, and Noack volatilities to comparable lubricants without OSPs. Data from engine tests and field trials show that semi- and fully synthetic lubricants containing OSP possess all the performance advantages of ester-containing lubricants, with additional benefits in terms of engine and inlet system cleanliness. The results indicate that OSPs have excellent potential as synthetic lubricant base fluids.