Description Red Line MT90 is a 75W90 GL-4 gear oil that satisfies the gear oil viscosity requirements of 75W90, 80W90, 90 and motor oil viscosities of SAE 40, 10W40, and 15W40. Red Line MT90 offers high performance gear protection and longer synchro life. It offers quicker shifts and provides a perfect synchronized coefficient of friction, eliminating notchy shifting, even when cold. MT90 can be used in GL-1, GL-3, and GL-4 applications, as well as where most special synchromesh fluids are specified. It’s safe for brass synchros because it lacks the reactive sulphurs found in most GL-5 oils that cause damage. About Red Line Gear Oil for Manual Transmissions Excellent gear and synchro protection, balanced slipperiness for easier shifting in cold climates Excellent for high-mile and low-mile transmissions Compatible with petroleums and other synthetics
