Unlike conventional oil, which is distilled from crude oil, synthetic oil is built in the laboratory. Formulators start with individual molecules, typically ethylene, and build the lubricant from the ground up. This allows formulators to use only pure, uniform molecules beneficial for lubrication. As a result, synthetic oil provides benefits conventional motor oil simply can't match, including increased wear protection, improved engine cleanliness and maximum fuel economy. While synthetic oil offers benefits for all vehicles, it's especially beneficial for modern vehicles that use technologies like turbochargers, direct fuel injection and variable-valve timing to improve fuel economy and reduce emissions. These technologies increase heat and contaminants, which can lead to engine, turbo and fuel-injector deposits that reduce performance and shorten life. For best engine protection and performance, use synthetic oil and a high-quality oil filter in combination with good fuel additives.
Automakers are increasingly using lower-viscosity oil and transmission fluid to improve fuel economy. While viscosity is defined as "resistance to flow," it's helpful to think of it as the oil's thickness. The lower the motor oil's viscosity, the more readily it flows. For example, a 0W-20 motor oil will flow faster than a 10W-40 motor oil. Oil viscosity has a direct influence on lubricating-film thickness and wear protection. Your engine is designed to use a motor oil of a specific viscosity; using an oil that's too thin can reduce wear protection, while using an oil that's too thick can increase chemical breakdown (oxidation) and reduce fuel economy. It's important to use the correct oil viscosity for your engine. To find the right viscosity of AMSOIL motor oil for your vehicle, use our product lookup.
Motor oil isn't "one-size-fits-all." Different vehicles and equipment require different motor oil types. For example, there is gasoline motor oil, European motor oil designed for the unique needs of European vehicles, diesel oil, racing oil and natural gas engine oil. Gasoline motor oil is made specifically for gas-powered engines, which are increasingly requiring lighter-viscosity oils formulated to maximize fuel economy. European motor oil is available in a wide range of viscosities and formulations designed to meet strict European automaker specifications. Diesel oil, meanwhile, is usually available in a higher viscosity, such as 15W-40, designed to deliver extra wear protection for powerful diesel engines. Racing oil is formulated to withstand the intense environment common to high-horsepower, high-torque racing engines. Since racing oil is changed so frequently, it doesn't contain the same level of detergency additives as gasoline motor oil. Natural gas engine oil is designed to combat issues specific to natural-gas engines, like valve recession and port blockage due to carbon deposits. Make sure to select the right type of motor oil for your engine.