Silkolene Pro S is simply one of the best quality engine oils there is! It's an ester based fully synthetic motor oil created to meet the most demanding use. Silkolene Pro S is available in 3 different viscosity grades - Pro S 5W/30, Pro S 5w/40 (this product) and Pro S 10W/50. Silkolene Pro S 10W/50 is particularly recommended for use in warmer ambient temperatures. 5w/40 is particularly suitable for Mitsubishi EVO models, Subaru Impreza WRX / STi, Nissan 200SX and other high performance vehicles. Silkolene Pro S is suitable for use in all modern cars and is particularly recommended for high performance engines. The full synthetic base fluid ensures that the products are thermally stable and extremely resistant to oxidation, even when stressed to the extremes of endurance. The excellent overall performance profile ensures optimum protection even in the most demanding turbo-charged power units in modern performance cars. The discerning motorist may be confident that the products excel in all areas of performance and ensure maximum protection under all operating conditions. Standards:API SJ, SL, CF ACEA A3, B3 BMW & Mercedes Silkolene Pro S 5w/40 is also known as: Silkolene Pro Race 5w-40 oil Silkolene ester synthetic 5w-40 oil Silkolene Pro S competition engine oil