Thermally stable, low traction coefficient lubricant

A lubricant composition comprising:

• a) a hydrocarbon lubricating base stock,
• b) a viscosity modifier composition comprising a ratio of between 90/10 to 40/60 wt % of polymer i)/ii) of:
• i) 0.1 to 20 wt. % of at least one olefin copolymer having a number average molecular weight (“Mn”) as measured by Gel Permeation Chromatography (“GPC”) with a polystyrene standard of about 1000 to about 10,000 wherein the olefin copolymer comprises an ethylene/propylene copolymer,
• ii) 0.1 to 10 wt. % of at least one grafted olefin copolymer having an Mn as measured by GPC with a polystyrene standard of about 1000 to about 10,000, comprising carboxylic acid functionality or a reactive equivalent thereof grafted onto a polymer backbone comprising an ethylene/propylene copolymer, wherein the carboxylic acid functionality or reactive equivalent thereof is further substituted with an amine.