Fuel additives and formulations for improving performance of gasoline direct injection engines

A method of reducing carbonaceous deposits in a gasoline engine, said method comprising adding an additive composition to a fuel that is gasoline, oxygenate, or mixtures thereof and operating the gasoline engine, wherein the additive composition comprises:

• a. an acylated detergent that is the reaction product of:
• i. a hydrocarbyl-substituted acylating agent wherein the hydrocarbyl-substituted acylating agent is a hydrocarbyl-substituted succinic acid and/or hydrocarbyl-substituted succinic anhydride;
• and
• ii. a nitrogen containing compound having at least one amino group that is quaternizable and at least one oxygen or nitrogen atom capable of reacting with said hydrocarbyl-substituted acylating agent,
• wherein acylated detergent is quaternized with a quaternizing agent comprising at least one dialkyl sulfate, alkyl halide, hydrocarbyl substituted carbonate, carboxylate, alkyl ester, hydrocarbyl epoxides, hydrocarbyl epoxides in combination with an acid, or mixtures thereof and wherein the acylated detergent is present in said additive composition at 5 wt % to 50 wt %, based on a total weight of said additive composition;
• b. 20 wt % to 80 wt % of a Mannich detergent that is the reaction product of a polyolefin, an aldehyde, and ammonia or an amine that may optionally be quaternizable;
• and
• c. 10 wt % to 60 wt % of a polyether and/or a polyetheramine,
• wherein the additive composition is present at 25 ppm to 2500 ppm on an actives basis, based on a total weight of the fuel.