The OTR Fully Synthetic SAE 50W Manual Transmission Oil delivers Expertise Built In as a reliable, replacement transmission lubricant. OTR transmission oil contains anti-wear additives as well as rust, oxidation and corrosion inhibitors that protect bearings and synchronizers, reduce component wear and promote longer transmission and lubricant life. This heavy duty transmission oil is suitable for use in applications calling for API MT-1 EP gear oil service classification and for use in transmissions and gear cases where API Service GL-1 through GL-4 is required. This heavy duty synthetic transmission oil provides excellent performance over a wide temperature range, including sub-zero service, promoting smoother, easier shifting. FleetPride is your First Click in Heavy Duty .