We use Red Line Synthetic Oil in all of our BMW PRO3 and Spec Miata race cars, as well as our customers' race cars. Great all-weather viscosity grade for gasoline engines in cars and light trucks that are driven on the street on a daily basis. More power and economy while providing thicker bearing oil films at operating temperature than a petroleum 10W40. Best choice to replace a 5W30 or 10W30, petroleum-based or other-brand synthetic oil if maximum durability is preferred. Acceptable for engines that are occasionally operated in extreme cold weather.