Peak Performance for advanced friction protection. Provides resistance to thermal breakdown, protection against harmful deposits, and controls oxidation. Gives security in changing climates and temperatures. Resists oil thickening and consumption. Keep your engine performing at it's peak with Quaker State Peak Performance . Quaker State conventional product, Peak Performance protects against the harmful effects of friction and is backed by our 10 year/250,000 mile lubrication limited warranty, even for those who change their own oil. Quart.