Tundra Full Syn is a full synthetic, ester-based 2-stroke engine oil specifically formulated for snowmobiles operating in cold climate extremes. Outstanding performance in DFI engines. Ultra clean burning, smokeless formulation utilizes surface-active esters and anti-wear additives to ensure optimal anti-scuff protection. Advanced, low-ash additive system prevents piston ring and exhaust power valve sticking, keeping your engine running clean and free of corrosion and deposits.