High octane number ethanol-gasoline blends: Quantifying the potential benefits in the United States

► Higher ethanol blend levels are projected for US gasoline. ► Ethanol has greater Research Octane Number (RON) and heat of vaporization (HoV) than gasoline. ► Linear molar octane blending model is used to quantify RON potential from ethanol and blendstock. ► Cooling octane from fuel evaporation in DI engines is estimated. ► Future engine efficiency increases are enabled by increased knock resistance of such fuels.