Patent ID: 7938867

Claim:
A process for increasing the efficiency of an exhaust after-treatment device of an internal combustion engine, comprising: operating the engine with a fuel composition comprising (a) a detergent/dispersant additive in a medium substantially free of to free of sulphur; and (b) a liquid fuel; wherein the contribution of component (a) to the total sulphur content of the fuel composition is less than about 20 ppm by weight, and the exhaust after-treatment device is suitable for reducing emissions of at least one member of the group consisting of particulate matter, NO x gases, and mixtures thereof to less than about 600 ppm by weight; and wherein the medium substantially free of to free of sulphur comprises an aliphatic hydrocarbon solvent having a flashpoint of about 120° C. or higher; and wherein the composition does not contain an emulsified fuel.