The main purpose of putting motor oil into a an engine is to lubricate the parts inside. Inside of a car's engine there are many moving parts that, without lubrication, would rub against one another, creating extreme levels of friction and wear. Motor oil acts as a lubricant between these parts within the internal combustion engine of an automobile, effectively reducing wear, friction, and heat production. Without motor oil, a car's engine would wear out quickly, become extremely inefficient, and ultimately fail.
There are three major categories of motor oil, each with its own advantages and disadvantages. Conventional motor oil is derived from crude oil, and is constituted entirely of petroleum products. Synthetic motor oil, however, is derived from a synthetic base like synthetic esters or other man-made chemicals, many of which are also created using petroleum products. Synthetic blend motor oil is made up of a blend of both synthetic and conventional motor oil.
Most experts agree that synthetic motor oil is the best option. While synthetic motor oil is more expensive than conventional motor oil or synthetic blend motor oil, it also provides better lubrication, has a much longer life within the engine (doesn't need to be changed as often), helps increase engine efficiency and performance, and performs better at extreme temperatures. For those who cannot afford true synthetic motor oil, synthetic blends are another good option. Those who use conventional motor oil will spend less on motor oil, but may end up paying more in vehicle maintenance and may need to change their oil more often, thus negating the cheapness of the conventional motor oil.
