The high temperatures on these parts would cause conventional oils to breakdown much faster than synthetic oil. Conventional base oils can handle up to 320°F operating temperatures, but synthetic base oils can handle up to 554°F operating temperatures. The improved thermal stability of synthetic oil provides increased oil longevity. These shear stable oils allow us to safely run lower viscosity oils that increase horsepower – without the danger of viscosity breakdown. Joe Gibbs Driven racing oils maintain their viscosity even after 500 miles of competition, so our parts stay cool and well lubricated. Available in quarts and cases of 12. Available only in the US and can only be shipped via UPS Ground.