Engine power and efficiency erodes over time when piston rings stop sealing due to wear and deposits. For maximum power from your engine, the combustion chamber must seal completely during the compression and combustion strokes. Piston deposits and wear cause loss of compression and loss of horsepower. Amsoil prevents piston deposits 93% more than required by industry standards. It also offers 75% more protection against horsepower loss than required by industry standards. Read More about maintaining your engine’s horsepower here.