GB934375A - Improved fuel compositions - Google Patents

Abstract

A fuel composition for use in spark ignited internal combustion engines comprises (a) a hydrocarbon mixture having a research octane number of at least 90 and containing at least two hydrocarbon types selected from paraffins, naphthenes, olefins and aromatics, (b) an organometallic antiknock agent in an octane number improving amount which is at least 1 cc. per U.S. gallon of fuel if tetraethyl lead or not more than 2g. of manganese per U.S. gallon if methyl cyclopentadienyl manganese tricarbonyl and (c) a co-antiknock compound selected from <FORM:0934375/III/1> and <FORM:0934375/III/2> in an amount not less than 0,1% by volume and not more than 1% by wt. of carbonyl based on the fuel wherein n is 1 or 2, each R1 is a C1-C10 alkyl, aryl, cycloalkyl, alkylaryl, arylalkyl, or alkyl having 1-3 fluorine atoms on the terminal carbon, group, each R11 is hydrogen or an alkyl, aryl, arylalkyl, alkylaryl, cycloalkyl, cycloalkylalkyl or alkylcycloalkyl group, and R111 is a C1-C6 alkyl, aryl or cycloalkyl group. Other specified organo-metallic antiknock agents are tetra-n-propyl lead, cyclopentadienyl nickel nitrosyl, tris(acetylacetonate)-rion, -nickel or -cobalt, iron-, cobalt-or nickel-2-ethyl salicylate, bis(n-butyl salicyaldimine) nickel and vanadium acetylacetonate. Optional additives include dye, ethylene dibromide, ethylene dichloride, tricresyl phosphate, dimethyl xylyl phosphate, diphenyl cresyl phosphate, alkyl boronic acids, lower alkyl phosphates and phosphites, ditertiarybutyl-4-methyl phenol, N,N1-disalicylal-1,2-propanediamine, polymerized linoleic acids and N,C-disubstituted imidazolines. Antiknock additives may comprise mixtures of the organometallic and carbonyl compounds in a weight ratio of 1,2-2,2 parts of carbonyl per part by weight of tetraethyl lead or 60-110 parts of carbonyl per part of manganese in methyl cyclopentadienyl manganese tricarbonyl.