Bel-Ray EXP Synthetic Ester Blend 4T Engine Oil Bel-Ray EXP Synthetic Ester Blend 4T Engine Oil is a 4-stroke motorcycle oil that combines the finest quality synthetic oils with select mineral base oils ensuring the highest level of protection for all 4-stroke motorcycles. Contains shear resistant VI improvers to resist viscosity breakdown. Suitable for air-cooled/liquid-cooled 4-stroke engines and wet clutches. Features: Synthetic ester blend with extreme pressure (anti-wear) additives deliver exceptional protection and horsepower Extends change intervals for air-cooled/liquid-cooled 4T engines with wet clutches Superior transmission and wet clutch performance API SN, certified Jaso MA2