Abstract: An engine lubricant, especially an SAE OW engine lubricant is described. The engine lubricant has at least 15 wt % of at least one monoester and not more than 15 wt % of additives, wherein said at least one monoester, or mixture of said monoesters if more than one is present, has a kinematic viscosity at 100° C. of not more than 3.3, a viscosity index of at least 130 and a Noack evaporation loss of not more than 15 wt %. The monoester is preferably the reaction product of a monohydric alcohol and a monocarboxylic acid wherein said monohydric alcohol is at least one saturated branched-chain aliphatic monohydric alcohol having between 16 and 36, carbon atoms and wherein said monocarboxylic acid is at least one saturated straight-chain aliphatic monocarboxylic acid having between 5 and 10, preferably 5 and 7, carbon atoms. In preferred lubricants, the monoester, or mixtures of monoesters, have a pour point of not more than ?30° C. and a non-polarity index of at least 80.

Abstract: An engine lubricant, especially an SAE OW engine lubricant is described. The engine lubricant has at least 15 wt % of at least one monoester and not more than 15 wt % of additives, wherein said at least one monoester, or mixture of said monoesters if more than one is present, has a kinematic viscosity at 100° C. of not more than 3.3, a viscosity index of at least 130 and a Noack evaporation loss of not more than 15 wt %. The monoester is preferably the reaction product of a monohydric alcohol and a monocarboxylic acid wherein said monohydric alcohol is at least one saturated branched-chain aliphatic monohydric alcohol having between 16 and 36, carbon atoms and wherein said monocarboxylic acid is at least one saturated straight-chain aliphatic monocarboxylic acid having between 5 and 10, preferably 5 and 7, carbon atoms. In preferred lubricants, the monoester, or mixtures of monoesters, have a pour point of not more than ?30° C. and a non-polarity index of at least 80.