The Brad Penn® Penn Grade 1® High Performance Oils contain the higher level of anti-wear (ZDDP – zinc dialkyldithiophosphate) and enhanced film strength so critical to proper high performance engine protection. The Penn-Grade 1® oils “typical” 1,500 ppm Zinc (Zn) and 1340-1400 ppm Phosphorus (P) content provide the needed anti-wear protection to critical engine parts, such as piston/cylinder walls, roller cams under heavy valve spring pressure and especially those that employ a solid “flat tappet” type system. As important as the chemistry is to the Penn-Grade 1® oils, it is by no means the whole story. The unique base oil cut used to refine the Penn-Grade 1® High Performance Oils maintain a tremendous affinity to metal surfaces. This naturally occurring “metal wetting” characteristic enables the oil to stay put on your highly stressed engines and makes the Penn-Grade 1® High Performance Oil resist slinging for an extended period of time. Also, rest assured in knowing that the Penn-Grade 1® High Performance Oils are 100% Made in the USA.