These products contain the extreme pressure additives necessary for ultimate protection road cars and racing vehicles, as well as friction modifiers for proper limited-slip operation Fully-synthetic formulas created from polyolester base stocks, offer excellent lubrication under extreme conditions. High viscosity-index (VI) to provide relatively constant viscosity and film thickness with varying temperature change. Ester base stocks and friction modifiers provide additional slipperiness to lower operating temperatures by reducing the sliding friction in hypoid gears Details: Sold as 1 Quart Superior shear stability and reduced oxidation compared to other synthetics and conventional gear oils Exceed API GL-5 specifications Engineered to provide the highest degree of protection and improvement of differential efficiency for better mileage, longer drain intervals, and less wear Most popular Red Line gear oil, with thousands of applications for passenger cars, light trucks and racing vehicles Contains additional friction modifiers for suitability with clutch-type limited slip differentials - for most LSDs, no additional friction modifiers are required This product is not designed for use in most manual transmissions or trans axles in passenger vehicles, since the extreme slipperiness may cause synchronizer mesh issues that lead to shifting problems Recommended for API GL-5, GL-6, MT-1, MIL-L-2105E, SAE J2360 and Chrysler spec MS-9763 Suitable replacement for a differential calling for an 80W90 or SAE 90 gear oil