A copolymer obtained by copolymerization of at least: an apolar monomer (m.sub.a) with the following formula (I), where u=0 or I, w=0 or I, E=-0- or NH(Z), or OCO, or NHCO or CONH, wherein Z is H or an alkyl group, and G is a group selected among an alkyl, an aromatic ring and an arylalkyl; and a polar monomer (m.sub.b) selected among those of the following formula (II), wherein t=0 or I, Q is selected among the oxygen atom and the NR group, wherein R is selected among a hydrogen atom and hydrocarbon chains, and R is a hydrocarbon chain substituted by at least one quaternary ammonium group and optionally one or more hydroxyl groups. The invention also relates to the use of such a copolymer as a detergent additive in a liquid fuel of an internal combustion engine.

A composition including a pyrolysis oil and, as an additive, one or more of: (a) an aldehyde-alkylphenol copolymer and/or an aldehyde-alkylphenol-polyamine copolymer, wherein the alkylphenol of the copolymer comprises an alkyl group having at least 30 carbon atoms; and (b) the reaction product of an alcohol and/or amine with a copolymer of an alpha-olefin and an ethylenically unsaturated carboxylate compound, wherein the alpha-olefin and/or the alcohol and/or amine has at least 30 carbon atoms. A method of reducing the pour point of a composition including a pyrolysis oil and a use of the aforementioned additives for reducing the pour point of a composition comprising a pyrolysis oil, are also disclosed.

The present invention provides a lubricating oil composition including a viscosity index improver (A) containing a comb-shaped polymer and having an SSI (shear stability index) of 30 or less together with a base oil, wherein an HTHS viscosity (high temperature high shear viscosity) at 150 C. (T.sub.150) is 1.6 to 2.9 mPa.Math.s, and a ratio of a kinematic viscosity at 40 C. (V.sub.40) [mm.sup.2/s] to the HTHS viscosity at 150 C. (T.sub.150) [mPa.Math.s] (V.sub.40/T.sub.150) is 12.4 or less. The lubricating oil composition of the present invention is excellent in fuel consumption reducing properties in a low-temperature region assuming the time of starting an engine while making various properties, such as a viscosity, etc., in a high-temperature region assuming the time of high-speed operation of an engine favorable.

The present invention relates to a composition of additives comprising: at least one first compound selected from: (i) copolymers of ethylene and vinyl acetate having a molar mass Mn included in the range ranging from 10,000 to 60,000 g.Math.mol1, optionally grafted by at least one alkyl (meth)acrylate group, the alkyl chain of which is saturated and contains from 12 to 30 carbon atoms; and (ii) polymers comprising at least 90 mol % of units derived from alkyl. (meth)acrylate monomer, the alkyl chain of which is saturated and contains from 18 to 22 carbon atoms; and at least one second compound selected from the modified alkylphenol-aldehyde resins. The invention also relates to the use of this composition of additives for lowering the viscosity of a liquid petroleum product such as a crude oil and for reducing the deposition of paraffins.

A fuel composition comprising as an additive the reaction product of a polycarboxylic acid having no more than 5 carbon atoms per carboxylic acid group, or an anhydride thereof and an alcohol having at least 5 carbon atoms.