Ethanol-diesel fuel composition and methods thereof

A fuel composition, comprising:

• (a) a diesel fuel;
• (b) ethanol;
• and
• (c) a surfactant comprising
• (1) a hydrocarbylphenol or derivative thereof that is a Mannich base or an alkoxylated Mannich base;
• (2) a reaction product of a hydrocarbyl-substituted polycarboxylic acid or anhydride and an alcohol, an amine, an amino alcohol, an epoxide, or a mixture thereof;
• or
• (3) a mixture thereof
• wherein the hydrocarbyl substituent of components (c)(1) and (c)(2) contains 4 to 20 carbon atoms;
• the ethanol comprises anhydrous ethanol containing up to about 0.1% by weight water, fuel grade ethanol containing up to 0.1% by weight water, or mixtures thereof;
• the diesel fuel is present at 50 to 99% by weight;
• the ethanol is present at 0.5 to 25% by weight;
• and the surfactant is present at 0.1 to 8% by weight and has a HLB value ranging from −30 to 20.