Red Line 75W90 is the most popular gear oil in the range, with thousands of applications for passenger cars and racing vehicles. It contains additional friction modifiers for suitablity 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 tranaxles, since the extreme slipperiness may cause synchronizer mesh issues that lead to shifting problems.