Additive and fuel compositions containing detergent and fluidizer and method thereof

A fuel additive composition, comprising:

• (a) a Mannich reaction product of a hydrocarbyl-substituted phenol wherein the hydrocarbyl substituent has a number average molecular weight of from 500 to 3000, an aldehyde, and an amine;
• wherein the amine comprises a secondary monoamine;
• and
• (b) a polyetheramine represented by the formula R[OCH2CH(R1)]nA wherein R is a hydrocarbyl group;
• R1 is selected from the group consisting of hydrogen, hydrocarbyl groups of 1 to 16 carbon atoms, and mixtures thereof;
• n is a number from 2 to about 50;
• A is —OCH2CH2CH2NR2R2 wherein each R2 is independently hydrogen or hydrocarbyl;
• and
• the weight ratio on an actives basis of component (a) to component (b) is from 1:5.5 to 1:9.5.