A method of cleaning up internal diesel injector deposits in a severely fouled engine, the method including combusting in the engine a diesel fuel composition having (a) a quaternary ammonium salt additive; and (b) one or more further nitrogen-containing detergents; in which the quaternary ammonium salt additive includes the quaternised reaction product of a hydrocarbyl substituted succinic acid derived acylating agent and a compound able to react with said acylating agent and which includes a tertiary amine group; in which each molecule of the hydrocarbyl substituted succinic acid derived acylating agent includes on average at least 1.2 succinic acid moieties.

Concentrates containing specific functionalised diblock copolymers serve as effective additives for improving the cold flow behaviour of fuels and oils, the copolymers being derived from a terminally-unsaturated intermediate polymer obtained via a metallocene process involving hydrogen.

The present invention relates to novel uses of corrosion inhibitors in fuels and lubricants.

A diesel fuel composition including (a) a quaternary ammonium salt additive; and (b) one or more nitrogen-free detergents; wherein the quaternary ammonium salt additive includes the quaternised reaction product of a hydrocarbyl substituted succinic acid derived acylating agent and a compound able to react with said acylating agent and which includes a tertiary amine group; wherein each molecule of the hydrocarbyl substituted succinic acid derived acylating agent includes on average at least 1.2 succinic acid moieties.

The present invention relates to the use of an olefin-carboxylic acid copolymer, wherein the copolymer comprises at least one free carboxylic acid side group, or of a nitrogen compound quaternized with epoxide in the presence of an olefin-carboxylic acid copolymer, wherein the copolymer comprises at least one free carboxylic acid side group, as a fuel additive or lubricant additive; to processes for preparing additives of this kind, and to fuels and lubricants additized therewith; such as, more particularly, as a detergent additive; for reduction or prevention of deposits in the injection systems of direct injection diesel engines, especially in common rail injection systems, for reduction of the fuel consumption of direct injection diesel engines, especially of diesel engines with common rail injection systems, and for minimization of power loss in direct injection diesel engines, especially in diesel engines with common rail injection systems; and as an additive for gasoline fuels, especially for operation of DISI engines.

The present invention is a polymer having structural units, units of formula I, units of formula II and units of either formula IIIa or formula IIIb:

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The polymer improves the low-temperature properties of fuel oils from petroleum sources and especially from vegetable or animal sources.

The present invention relates to novel uses of corrosion inhibitors in fuels and lubricants.

The present invention relates to novel uses of corrosion inhibitors in fuels and lubricants.

A composition including a pyrolysis oil and, as an additive: (a) one or more nitrogen containing antioxidants is disclosed. An additive composition for a pyrolysis oil including is also disclosed, the additive composition including (a) one or more nitrogen containing antioxidants; and optionally: (b) a copolymer including maleic anhydride derived units and -olefin derived units; and/or (c) the reaction product of a carboxylic acid and a polyamine. Also disclosed is a method of improving including the oxidation stability of a composition including a pyrolysis oil, the method including adding to the composition (a) one or more nitrogen containing antioxidants, and a related use of said nitrogen containing antioxidants. Such methods and uses are also disclosed for the improvement in storage stability of compositions including a pyrolysis oil.

A method of cleaning up internal diesel injector deposits in a severely fouled engine, the method including combusting in the engine a diesel fuel composition having (a) a quaternary ammonium salt additive; and (b) one or more further nitrogen-containing detergents; in which the quaternary ammonium salt additive includes the quaternised reaction product of a hydrocarbyl substituted succinic acid derived acylating agent and a compound able to react with said acylating agent and which includes a tertiary amine group; in which each molecule of the hydrocarbyl substituted succinic acid derived acylating agent includes on average at least 1.2 succinic acid moieties.