A method of improving the low temperature properties of a middle distillate fuel composition comprising: (a) a nitrogen-containing dispersant; and (b) one or more low temperature property enhancers which are not fumarate vinyl ester copolymers and which are selected from (x) wax antisettling additives; (y) middle distillate flow improvers and mixtures thereof; the method comprising adding to the fuel an additive (c) which is a copolymer comprising units of formula (A): and units of formula (B): wherein R is an alkyl group and each of R.sup.1 and R.sup.2 is an alkyl group.

##STR00001##

Use of a liquid fuel composition in an internal combustion engine, the internal combustion engine containing a lubricating composition for lubricating said internal combustion engine, wherein the liquid fuel composition comprises at least one nitrogen-containing detergent additive, for the purpose of reducing engine wear caused by the presence of soot in the lubricating composition.

Use of a liquid fuel composition in an internal combustion engine, the internal combustion engine containing a lubricating composition for lubricating said internal combustion engine, wherein the liquid fuel composition comprises at least one nitrogen-containing detergent additive, for the purpose of reducing engine wear caused by the presence of soot in the lubricating composition.

The present technology is related to amide or ester containing quaternary ammonium salts having a hydrocarbyl substituent of number average molecular weight ranging from 300 to 750, and the use of such quaternary ammonium salts in fuel compositions to improve the water shedding performance of the fuel composition.

The present disclosure provides a pour point dispersant composition comprising an alkoxylated alkyl amine polyester. The pour point depressant composition may optionally be combined with a solvent and added to a hydrocarbon composition to improve the cold-flow properties of the hydrocarbon composition.

The present disclosure provides a pour point dispersant composition comprising an alkoxylated alkyl amine polyester. The pour point depressant composition may optionally be combined with a solvent and added to a hydrocarbon composition to improve the cold-flow properties of the hydrocarbon composition.

A fuel additive composition includes: (a) one or more copolymers including:

at least one unit of formula (I) below:

##STR00001##

with u=0 or 1, E=—O— or —N(Z)—, or —O—CO—, or —CO—O— or —NH—CO— or —CO—NH—, with Z representing H or a C.sub.1-C.sub.6 alkyl group, G represents a group chosen from a C.sub.1-C.sub.34 alkyl, an aromatic nucleus, an aralkyl including at least one aromatic nucleus and at least one C.sub.1-C.sub.34 alkyl group, and —at least one unit of formula (II) below:

##STR00002##

in which R.sub.1″ is chosen from a hydrogen atom and a methyl group, Q is chosen from an oxygen atom and a group —NR′— with R′ being chosen from a hydrogen atom and C.sub.1 to C.sub.12 hydrocarbon-based chains, R comprises a C.sub.1 to C.sub.34 hydrocarbon-based chain substituted with at least one quaternary ammonium group.

Amines and amine derivatives that improve the buffering range, and/or reduce the chelation and other negative interactions of the buffer and the system to be buffered. The reaction of amines or polyamines with various molecules to form polyamines with differing pKa's will extend the buffering range, derivatives that result in polyamines that have the same pKa yields a greater buffering capacity. Derivatives that result in zwitterionic buffers improve yield by allowing a greater range of stability.

The invention relates to quaternary ammonium amide and/or ester salts and their use as additives, including their use in fuels, such as diesel fuel. The invention particularly relates to the use of quaternary ammonium amide and/or ester salts as detergents in diesel fuels.

Ethylene-C.sub.3-C.sub.10 alpha olefin copolymers, dispersants and lubricating oils/fuel compositions incorporating dispersants, and related methods are generally described herein. The copolymer may comprise ethylene-derived units and C.sub.3-C.sub.10 alpha-olefin-derived units. The C.sub.3-C.sub.10 alpha-olefin-derived units may have a carbon number from three to ten. For example, the C.sub.3-C.sub.10 alpha-olefin-derived units may be propylene-derived units. The dispersants may be made from copolymers having low metal and/or fluorine contents.