Slick 50 Synthetic Engine Treatment (15 oz) Meets GF5 requirements which helps reduce emissions and maximize fuel economy Creates an enhanced protective layer of lubrication to minimize heat produced by friction Forms a continuous, self-regenerating shield between engine parts to prevent metal to metal wear and enhance oil durability Helps fight ethanol, rust and water build up in the crankcase,caused by cylinder wash and blow-by, which can cause rust,white sludge and even ice build up in frozen conditions Helps unleash maximum horsepower and ultimate performance