| 主权项 |
1. A method for improving the performance of a direct fuel injected diesel engine comprising operating the engine on a fuel composition comprising a major amount of fuel and from about 5 to about 100 ppm by weight based on a total weight of the fuel composition of a quaternary ammonium salt, said salt having a thermogravimetric analysis (TGA) weight loss of greater than 50 wt. % at 350° C., wherein the quaternary ammonium salt comprises a compound of the formula wherein each of R1, R2, R3, and R4 is selected from a hydrocarbyl group containing from 1 to 25 carbon atoms, wherein at least one and not more than three of R1, R2, R3, and R4 is a hydrocarbyl group containing from 1 to 4 carbon atoms, at least one of R1, R2, R3, and R4 is a hydrocarbyl group containing from 8 to 25 carbon atoms, M− is derived from an acid selected from the group consisting of nitrous acid, acetic acid, propionic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, salicylic acid, 2-hydroxy-4-methylbenzoic acid, 2-hydroxy-4-ethylsalicylic acid, p-hydroxybenzoic acid, 3,5-di-tert-butyl-4-hydroxybenzoic acid, alkenyl succinic acids, 2-methylbutanedioic acid, 2-ethylpentanedioic acid, 2-n-dodecylbutanedioic acid, 2-n-dodecenylbutanedioic acid, 2,2-dimethylbutanedioic acid; 2,3-dimethylbutanedioic acid; 2,3,4-trimethylpentanedioic acid; 2,2,3-trimethylpentanedioic acid; and 2-ethyl-3-methylbutanedioic acid, 2-dodecylbut-2-enedioic acid; and 2-polyisobutylbut-2-enedioic acid, phthalic acid, isophthalic acid, terephthalic acid and substituted phthalic acids, 3-methylbenzene-1,2-dicarboxylic acid; 4-phenylbenzene-1,3-dicarboxylic acid; 2-(1-propenyl)benzene-1,4-dicarboxylic acid, 3,4-dimethylbenzene-1,2-dicarboxylic acid, and mixtures thereof. |
