Lucas HD gear oil:

Gear oils have needed improving for years, especially in the high performance industry. The Lucas 80W-90 & 85W-140 enjoys the technology Lucas developed in making the "Lucas Heavy Duty Oil Stabilizer", the number one supplemental oil in the heavy duty industry. This gear oil formula is fortified with special anti-wear agents and lubricity agents to control wear and drag as well as special additives to control heat. These features are not found in ordinary gear oils. This gear oil is both excellent for race cars and any heavy-duty application where plain gear oils just aren't good enough.

Lucas synthetic gear oil:

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 race cars and any heavy-duty application where plain gear oils just aren't good enough.