| abstract |
Combustion chamber deposits and intake valve deposits in a spark ignition internal combustion engine which uses a liquid hydrocarbon or liquid hydrocarbon-oxygenate fuel, by using an unleaded fuel to which has been added an additive selected from the group consisting of low boiling alkyl pyridines, 4-vinylpyridine, DMF, N-formylpiperidine, sulfolane, polyolefin, polyether or polyether amine derivatives of DMF, amidene, or N-substituted-2 pyrrolidones, polyolefin in an amount of at least about 1,000 wppm and mixtures thereof. Functionalized polymer detergents can be used alone and added to the fuels in amounts in of about at least 3,000 wppm. |