Vehicle owners have two basic choices in engine oils: synthetic and regular. Regardless of which oil is used, it must perform several functions in order to protect the vehicle's engine. First, it must provide lubrication between metallic surfaces. Next, the oil must be able to remove heat from the turning engine components. Lastly, it should have the ability and capacity to remove and collect harmful combustion by-products.
The viscosity of the oil also needs to be considered. The oil must be thin enough to arrive quickly at moving parts during the cold start up, but it must also be thick enough to sufficiently coat and cling to hot metallic parts.
Synthetic oil incorporates the same natural base components as traditional oils. However, the oil molecules have been changed so that they are uniform and consistent. This molecular consistency allows synthetic oils to perform well in temperatures greater than 400 degrees F, which is about twice that of regular oils. Traditional oils tend to break down under prolonged engine heat, and can lead to the formation of engine sludge if not regularly changed. Traditional oils contain contaminants and waxes, which prevent them from flowing freely at extremely low temperatures.
Synthetic oil is recommended for use in newer vehicles and performance vehicles, because of its small and consistent molecule size and its ability to flow freely in cold weather. Any kind of engine oil needs regular changing, though, due to the accumulation of combustion by-products, so most vehicles can use either type of oil without adverse effects. Excellent deals on name-brand oils can be found by watching for oil change deals at your local auto parts store. Additionally, you'll pay less per quart if you purchase oil in the 5-quart capacity container.