Asked By Anonymous
SAE is the Society Of Automotive Engineers (USA). The SAE rating of an oil is a measure of its viscosity (eg 20W50).
API is the American Petroleum Institute. The API rating of an engine oil covers the performance rating of the oil (e.g. SM for petrol, CF for diesel).
ACEA is a European industry body up of European vehicle manufacturers. The ACEA rating of an engine oil of covers the performance rating of the oil (e.g. A3/B3, C3).