Heat transfer fluids corresponding to mixtures of at least one hydrogen bond donor and at least one hydrogen bond acceptor are provided. The heat transfer fluids can have an unexpectedly high heat capacity relative to the expected heat capacity based on the heat capacities of the at least one hydrogen bond donor and the at least one hydrogen bond acceptor. In some aspects, the heat transfer fluids can also have a sufficiently high electrical resistivity to be suitable for use in environments such as heat management systems in electric vehicles.

A lubricant formulation contains: (a) greater than 50 weight-percent hydrocarbon base oil; (b) 5 weight-percent or more and less than 50 weight-percent of one or a combination of more than one oil soluble polyalkylene glycol selected from a group consisting of monol, diol and triol initiated 1,2-butylene oxide homopolymers and monol initiated copolymers of 1,2-butylene oxide and propylene oxide; (c) 0.1 weight-percent or more and 5 weight-percent or less of sulfurized olefin; and (d) 0.1 weight-percent or more and 2 weight-percent or less of phosphate ester; where weight-percent is relative to total lubricant formulation weight.

Disclosed is the use of a lubricating composition including at least one base oil and at least one polyalkylene glycol (PAG) produced by polymerisation or copolymerisation of alkylene oxides including between 3 and 8 carbon atoms, at least one of which being a butylene oxide, for preventing or reducing pre-ignition in an engine, preferably in a vehicle engine.

Disclosed is the use of a lubricating composition including at least one base oil and at least one polyalkylene glycol (PAG) produced by polymerisation or copolymerisation of alkylene oxides including between 3 and 8 carbon atoms, at least one of which being a butylene oxide, for preventing or reducing pre-ignition in an engine, preferably in a vehicle engine.

An additive package for an internal combustion engine crankcase lubricating oil composition, which additive package comprises or is made by admixing: (A) 5-99.4 mass % based on the mass of the additive package, of a diluent oil of lubricating viscosity; and (B) the following additives: (B1) 0.1-10 mass % of a polymeric friction modifier, on an active matter basis, based on the mass of the additive package, which polymeric friction modifier is the reaction product of (a) a functionalised polyolefin, (b) a polyether, (c) a polyol, and (d) a monocarboxylic acid chain terminating group (B2) 0.5 to 10 mass % on an active matter basis, based on the mass of the additive package of one or more ashless organic friction modifiers that include a polar terminal group covalently bonded to a monomeric oleophilic hydrocarbon chain.

An additive package for an internal combustion engine crankcase lubricating oil composition, which additive package comprises or is made by admixing: (A) 5-99.4 mass % based on the mass of the additive package, of a diluent oil of lubricating viscosity; and (B) the following additives: (B1) 0.1-10 mass % of a polymeric friction modifier, on an active matter basis, based on the mass of the additive package, which polymeric friction modifier is the reaction product of (a) a functionalised polyolefin, (b) a polyether, (c) a polyol, and (d) a monocarboxylic acid chain terminating group (B2) 0.5 to 10 mass % on an active matter basis, based on the mass of the additive package of one or more ashless organic friction modifiers that include a polar terminal group covalently bonded to a monomeric oleophilic hydrocarbon chain.

The use of a polyalkylene glycol of formula HO-(A-O).sub.p(CH.sub.2CH.sub.2O).sub.m-(A-O).sub.qH wherein A is a C.sub.3- to C.sub.20-alkylene group or a mixture of such alkylene groups, m is a number of from 2 to 100 and p and q are each numbers of from 1 to 100, as an additive in a fuel.

The use of a polyalkylene glycol of formula HO-(A-O).sub.p(CH.sub.2CH.sub.2O).sub.m-(A-O).sub.qH wherein A is a C.sub.3- to C.sub.20-alkylene group or a mixture of such alkylene groups, m is a number of from 2 to 100 and p and q are each numbers of from 1 to 100, as an additive in a fuel.

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.

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.