Lucas Oil Products Synthetic 0W-5 Pro Stock Oil is a 100% Synthetic, ULTRA-light viscosity, RACING MOTOR OIL. Developed for high RPM naturally aspirated gasoline engines, it is excellent for gapless or extra light tension rings. Provides maximum horsepower gains in Pro Stock, Pro Stock Bike and Competition Eliminator, while providing excellent protection and reducing friction at high RPM?s. An excellent qualifiying oil for NASCAR, NHRA, IHRA or any race engine designed to run lighter viscosity motor oils. Our exclusive Anti-Wear and Anti-Scuff Extreme Pressure additive package protects the valve train, bearings and cylinder walls. Designed to run at operating temperatures up to 190?F, although it will provide protection up to 250?F. Not intended for passenger car use.