Any internal combustion engine on a vehicle must be lubricated with compatible motor oil. Having a particular viscosity, this type of fluid protects and cools the various moving components of an engine block. Drivers could select several types of oil solutions based on several factors ranging from weather and driving habits to road surfaces and air quality. The Society of Automotive Engineers provides standard ratings on such important products that are widely available at auto service shops and auto stores. The appropriate interval for changing the motor oil in your vehicle is based on official recommendations from the manufacturer. Below is a brief overview of some common types of motor oils for engines in new and used vehicles.