Ethanol Fuel (E10, E85)

E5 and E10 are common petrol grades; E85 contains up to 85 % ethanol and needs flex-fuel vehicles. Ethanol raises octane but contains less energy, so consumption rises slightly. Most cars built in recent decades are approved for E10; manufacturers publish compatibility lists.

Fuel trim corrects for the different air-fuel ratio of ethanol blends.

Ethanol absorbs water and can attack some older rubber and plastic parts. Check compatibility before using E10 in older vehicles or small engines.