Redline MT-85 GL-4 is popular for owners with manual-transmission cars, as it does not contain the reactive sulfurs found in most GL-5 oils that cause damage, so it's safe for most manual transmission synchros. Other synthetic gear oils are often too slippery for proper synchro engagement, but MT-85 has the appropriate coefficient of friction, so it offers excellent gear and synchro protection, plus balanced slipperiness for easier shifting.
It also matches the required specs for BMW open/non-limited slip differentials made from 7/2011 production date. BMW switched from a GL-5 to a GL-4 oil specification at this date. Open diffs are found in nearly all non-M models so this would apply to all non-M2/M3/M4/M5/M6 models. This is an alternative to BMW 75W85 fluid part #83222295532 (and about 1/4 of the cost!).
- Matches required specs for 7/2011-later BMW non-M differentials
- Offers quicker shifts, perfect synchronizer coefficient of friction
- Eliminates notchy shifting
- High-performance gear protection and longer synchro life
- Recommended for GL-1, GL-3, and GL-4 applications as well as where most special synchromesh fluids are specified