The correct oil to use for a vehicle can be determined by referencing the vehicle's owner's manual, contacting a dealer or mechanic, checking a reference book at an auto parts store, or using an online utility. All of these methods are likely to result in the manufacturer's recommended oil, but there may be certain situations when a different oil should be used instead.
The most important characteristic of vehicle oil is the viscosity. Viscosity is an oil's resistance to flow, and it indicates how easily the oil flows through an engine at different temperatures. Different vehicles have different requirements for viscosity, and it is important that an oil is compatible with the engine it's used with.
In addition to viscosity, a driver must also choose between traditional oil, premium oil, fully synthetic oil or a synthetic oil blend. Each of these types has various pros and cons, such as its cleanliness, fuel efficiency and ability to adapt to different temperature ranges. The decision of what type of oil to select should be based on the driver's needs, the way that the vehicle is intended to be used, the age of the vehicle, and the number of miles on the vehicle.