For more articles please use the navigation menu. That generally will include basestocks and additives. Without focusing on performance characteristics, the most significant difference from one oil to another is how quickly breakdown occurs. Although there are many factors that contribute to the breakdown of an oil, heat is one of the most important. Depletion and decreased effectiveness of oil additives is also important, but that will be discussed later.
Petroleum oil begins to break-down almost immediately.
A high quality synthetic, on the other hand, can last for many thousands of miles without any significant reduction in performance or protection characteristics. Synthetics designed from the right combination of basestocks and additives can last indefinitely with the right filtration system. As alluded to above, the first major difference between petroleum and synthetic oil is heat tolerance. Flash point is the temperature at which an oil gives off vapors that can be ignited with a flame held over the oil. The lower the flash point the greater tendency for the oil to suffer vaporization loss at high temperatures and to burn off on hot cylinder walls and pistons.