Abstract: The present disclosure concerns engine lubricant compositions including at least one base oil, at least one viscosity index improver polymer and at least one polyalkylene glycol, obtained by polymerization or copolymerization of alkylene oxides comprising from 3 to 8 carbon atoms, including at least one butylene oxide, the quantity of polyalkylene glycol being from 1 to 28% by mass with respect to the total mass of lubricant composition. Using at least one polyalkylene glycol, obtained by polymerization or copolymerization of alkylene oxides including from 3 to 8 carbon atoms, further including at least one butylene oxide in a base oil improves engine cleanliness while not increasing, or indeed while decreasing, the consumption of petrol or diesel fuels by the engine.

Abstract: The present disclosure relates to a lubricant composition including at least one base oil and at least one organic compound. The lubricant composition thus makes it possible to reduce, or even to eliminate knock in a vehicle engine, preferably a motor vehicle engine.

Abstract: The present disclosure concerns engine lubricant compositions including at least one base oil, at least one viscosity index improver polymer and at least one polyalkylene glycol, obtained by polymerization or copolymerization of alkylene oxides comprising from 3 to 8 carbon atoms, including at least one butylene oxide, the quantity of polyalkylene glycol being from 1 to 28% by mass with respect to the total mass of lubricant composition. Using at least one polyalkylene glycol, obtained by polymerization or copolymerization of alkylene oxides including from 3 to 8 carbon atoms, further including at least one butylene oxide in a base oil improves engine cleanliness while not increasing, or indeed while decreasing, the consumption of petrol or diesel fuels by the engine.

Abstract: Lubricant compositions include: (a) one or more polyalkylene glycol base oils obtained by polymerization or copolymerization of alkylene oxides comprising from 3 to 8 carbon atoms, include at least one butylene oxide and (b) at least one detergent chosen from salicylates or phenates. The present disclosure also relates to: 1) use of a lubricant composition as engine oil, preferably as oil for the engines of petrol or diesel motor vehicles; 2) use of a group of additives for an engine lubricant comprising polyalkylene glycol bases obtained by polymerization or copolymerization of alkylene oxides comprising from 3 to 8 carbon atoms; and 3) use of at least one additive chosen from salicylates, phenates, dithiocarbamates, amine-based or phenol-based antioxidants, preferably from salicylates or phenates, for reducing the Noack volatility of the base oils of polyalkylene glycol type, obtained from alkylene oxides comprising from 3 to 8 carbon atoms.