Gear oils have needed improving for years, especially in the hi-performance industry. The Lucas L9 Racing Gear Oil provides excellent thermal stability and longevity throughout the entire drive train system. Recommended for use in both transmissions and differentials, Lucas specifically developed this formula with special anti-wear agents and lubricity agents to control wear and drag as well as special additives to control heat. This feature is not found in ordinary gear oils. This gear oil is both excellent for racecars and any heavy-duty application where plain gear oils just aren't good enough. With the use of our own gear box dyno and feedback from a major IRL Team, we have created these light weight friction free gear oils. They have already won in IRL, NASCAR, Pro Stock Car, Pro Stock Bikes and more. The new technology we developed for these gear oils will now be used in all Lucas Gear Oils. *L9 – Differentials & Transmissions *L10 – Transmissions *L11 – Quick Qualifier