Patent ID: 8425629

Claim:
A fuel composition comprising: a Mannich reaction product of a) a polyisobutylene alkylated hydroxyaromatic compound; b) formaldehyde or a reactive equivalent thereof; and c) a secondary monoamine component comprising dimethylamine; wherein the said polyisobutylene alkylated hydroxyaromatic compound is derived from a combination of a conventional polyisobutylene and a high vinylidene polyisobutylene; and wherein the said polyisobutylene alkylated hydroxyaromatic compound is derived by: i) combining the conventional polyisobutylene and the high vinylidene polyisobutylene prior to the alkylation of the hydroxyaromatic compound; or ii) combining a hydroxyaromatic compound alkylated with the conventional polyisobutylene and a hydroxyaromatic compound alkylated with the high vinylidene polyisobutylene; wherein the ratio of conventional polyisobutylene to high vinylidene polyisobutylene is from 25:75 to 40:60 on a weight basis; and wherein the Mannich reaction product is present in the fuel composition from 10 to 10,000 ppm.