The primary function of engine oil is to minimize metal-to-metal contact reducing friction and wear. With friction comes heat, which causes more wear and distorts moving engine parts. The oil in your engine maintains a thin, lubricating film on all metal parts that lets them glide over each other safely and efficiently, minimizing friction. Valvolinetm engine oils exceed the latest performance standards of leading engine manufacturers.
There are a lot of myths around engine oil, to clear up some of those myths and read more about what you can and cannot expect from engine oil and some do's and dont't, please : click here: myths and facts