S-4SR Snowmobile 4-cycle oil with NASCAR® proven technology is a 100% synthetic formula designed for high stressed 4-cycle racing engines in the most severe conditions. S-4SR is an MPZ® fortified formula that offers the ultimate in viscosity control, anti-friction, anti-wear and improved power output. It is formulated to reduce engine temperature and wear from high load conditions. A selective additive system and polymer chemistry also provides anti-oxidation, anti-foam, and anti-rust features to keep engines protected. S-4SR offers the best protection for engines running at high RPM, high temperatures and under extreme loads or endurance type conditions. S-4SR is recommended for use in air cooled or liquid cooled snowmobile 4-cycle engines commonly found in Arctic Cat®, Polaris®, Ski-Doo®, Yamaha® and other snowmobile applications.