| abstract |
Fuel additives and fuel additive compositions are described comprising: (i) at least one fuel-soluble detergent/dispersant which is (a) a fuel-soluble salt, amide, imide, oxazoline and/or ester, or a mixture thereof, of a long chain aliphatic hydrocarbon-substituted dicarboxylic acid or its anhydride, (b) a long chain aliphatic hydrocarbon having a polyamine attached directly thereto, and/or (c) a Mannich condensation product formed by condensing a long chain aliphatic hydrocarbon-substituted phenol with an aldehyde, and an amine; wherein the long chain hydrocarbon group in (a), (b) and (c) is a polymer of at least one Cā to Cāā monoolefin, said polymer having a number average molecular weight of at least about 300; (ii) a fuel-soluble cyclopentadienyl complex of a transition metal; and (iii) a fuel-soluble liquid carrier or additive induction aid. These compositions in use enable surprising improvements in intake valve deposit control as well as other advantages. |