Described herein are associative polymers capable of controlling one or more physical and/or chemical properties of non-polar compositions and related compositions, methods and systems.

The present disclosure relates to fuel additive packages, fuels, and methods of achieving emission particulate reductions in gasoline direct injection (GDI) engines using select Mannich detergents (e.g., reaction products of a hydrocarbyl-substituted hydroxyaromatic compound, an aldehyde, and an amine). In one approach or embodiment, the select Mannich detergents herein for emissions particulate reductions include one or more of the following characteristics: (i) certain molar ratios of the hydroxyaromatic compound, the amine, and the aldehyde; (ii) select oligomer structures; and/or (iii) certain isomeric forms of polyisobutylene substituents on the hydroxyaromatic compound.

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.

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.