Abstract: The present application relates to deposit control additive composition comprising of Mannich base and Polyisobutylene succinimide (PIBSI) having average molecular weight of about 800 as a synergistic component for hydrocarbon fuel, particularly diesel fuel along with other conventional additives such as fluidizer oil, dehazer, corrosion inhibitor, solvents, and optionally lubricity improver, antistatic agent and ignition accelerator to obtain diesel fuel composition. The application also relates to a process for the preparation of fuel composition by blending at an ambient temperature diesel fuel and deposit control additive formulation obtained by blending Mannich base, Polyisobutylene succinimide (PIBSI) fluidizer oil, dehazer, corrosion inhibitor, optionally lubricity improver, antistatic agent, ignition accelerator at a temperature ranging between 50° C. to 60° C. for a time period of up to 2 hours.

Abstract: The present application relates to deposit control additive composition comprising of Mannich base and Polyisobutylene amine (PIBA) having average molecular weight of 800 as a synergistic component of deposit control additive formulation. The application also relates to deposit control additive composition comprising further components such as fluidizer oil, dehazer, corrosion inhibitor and solvent to obtain deposit control additive formulation and mixed with gasoline fuel to obtain fuel composition. The application further relates to a process for the preparation of fuel composition by blending at an ambient temperature gasoline fuel and deposit control additive composition obtained by blending in a suitable container Mannich base, Polyisobutylene amine (PIBA), fluidizer oil, dehazer, corrosion inhibitor and solvent at a temperature ranging between 50° C. to 60° C. for a time period of up to 2 hours.

Abstract: An antioxidant composition effective for stabilizing gasoline and gasoline components contains from approximately 50-95% by weight of at least one Mannich base and from approximately 5-50% by weight of at least one amine. The Mannich base is derived from p-substituted phenols or from cashew nut shell liquid.