Conventional Oils Can t Take It Petroleum-based motor oils start out as crude oil that must be pumped from deep within the earth. Crude oil is a mixture of thousands of different organic compounds that can be separated through refining processes into products ranging from jet fuel to asphalt. In the same manner, petroleum motor oil is also a mixture of various compounds. However, the refining process has no way of separating compounds that have desirable properties from ones that do not. There is also no way of removing 100 percent of impurities such as waxes, asphalt and sulfur.
High temperatures cause petroleum oil to oxidize and break down.
This leads to the formation of sludge, lacquer, varnish and corrosive by-products. Lighter fractions of the petroleum evaporate, leaving a thicker oil behind. This thick oil is less protective and can become more solid than liquid when exposed to cold temperatures. They also offer protection over a wider temperature range. This increases engine performance, reduces emissions, and extends the engine's service life.