abstract |
Lubricating composition for use in the crankcase of an engine comprising: (i) a base oil comprising at least one monoester or a mixture of monoesters, wherein said monoester or mixture of monoesters has a kinematic viscosity at 100° C. of not more than 4 mm 2 /s, a viscosity index of at least 130 and a Noack evaporation loss of not more than 20 wt %; and (ii) a polymeric viscosity index improvers selected from (a) one or more comb polymers; (b) a poly(meth)acrylate polymer having 1 to 70 mol % of one or more (meth)acrylate structural units represented by formula (1) below (1) wherein R 1 is a hydrogen atom or a methyl group, and R 2 is a straight chain or branched hydrocarbon group having not less than 16 carbon atoms; (c) styrene-diene hydrogenated copolymers; and (d) mixtures thereof. The lubricating composition of the present invention provides improved fuel economy properties. |