Manual transmissions may use one of many different lubricants that vary in both chemical formulation and viscosity. The correct fluid for a particular manual transmission depends on the OEM recommended fluid and lubrication specification. Please see our manual transmission lubricant cross-reference chart for specific applications. Our products include Max ATF®, a synthetic automatic transmission fluid; Synchromax, a performance transmission fluid for manual gearboxes; and Racing ATF fluid, a high-performing lubricant for the track.
For assistance in selecting the best fluid for a transmission, please contact the Royal Purple Automotive Technical Department at 888-382-6300.
Max ATF provides unmatched wear protection and oxidation stability, and will also typically reduce transmission operating temperatures, especially in severe duty application.
Royal Purple Max ATF is an excellent, functional replacement for these fluids; however, it is not a warranty compliant replacement fluid because of the slight difference in viscosity. Consumers that wish to maintain strict OEM warranty compliance should use an OEM licensed/approved automatic transmission fluid. Applications for which strict warranty compliance is no longer a concern may use Max ATF as a performance upgrade replacement transmission fluid.
No, at this time we do not recommend Max ATF for use in CVTs.
For manual transmissions and transfer cases specifying the use of an ATF, we recommend either Royal Purple Max ATF or, for greater performance and protection, Royal Purple Synchromax.
No. All viscosities of Max-Gear are formulated with the limited-slip friction modifiers necessary for use in clutch or cone differentials. No additional additives are necessary.
Yes. Royal Purple Max gear oils can safely be used in any automotive axle, whether limited-slip, locker, spool, or open. In applications where the additive is not needed, it does not affect performance at all.
Yes. API GL-4 and GL-5 service category gear oils are, by definition, hypoid gear oils. Royal Purple Max Gear oils are recommended for use in GL-4 and GL-5 gear service.
Yes. Max-Gear possesses both API GL-5 and GL-4 certification. Max-Gear is formulated with Royal Purple’s proprietary Synerlec® additive technology to provide the exceptional film strength necessary for GL-5 applications, yet it is noncorrosive to soft yellow metals (brass, bronze, etc.) commonly used in manual transmissions that specify a GL-4 rated lubricant.