Motor oil is made from crude oil and is used to lubricate, clean, and cool engines. Types of motor oil include conventional, synthetic, diesel, bio-based, hybrid (blends of conventional and synthetic), and recycled oils. Motor oil varies in weight and viscosity, as well as additives that some manufacturers add to the oil during the refining process. A numerical code system created by the Society of Automotive Engineers (SAE) grades motor oils according to viscosity--the higher the number between 0 and 60, the more viscous (thicker) the oil is. Most consumer motor oils are graded by two numbers, with the first number indicating cold weather (Winter or "W") performance.
SAE 10W-40
This oil has a weight of SAE 10W-40, meaning it has an SAE viscosity rating of 10 in cold temperatures and a rating of 40 at normal operating temperature. Always check your vehicle's owner's manual to verify that this is the correct weight of motor oil for your vehicle.
Conventional Motor Oil
This oil is a conventional motor oil, meaning it is refined from crude oil or petroleum products. Conventional motor oils may or may not have additives included after refining. Conventional motor oils are more versatile than synthetic or hybrid motor oils, because they are suitable for use with nearly all types of modern vehicle engines, from cars and trucks to motorcycles, ATVs, farm equipment, and more.
Racing Oil
Racing oils are designed for track cars and other types of high-compression vehicles intended for motorsports competition. They contain particular additives for increased engine horsepower and reduced friction on metal parts, and provide special protection for engines with high compression or higher horsepower. Racing oils usually include fewer detergents than regular conventional motor oils.
Please note that many, if not all, oils labelled as racing oils are not street legal, and it is not recommended to put racing oil in a conventional passenger vehicle. Make sure to double-check the product label as well as the specifications of your vehicle to ensure proper usage.
