Bel-Ray EXS Synthetic Ester 10W40 4T Engine Oil 4 Liter 99161-B4LW &nbsp;Synthetic ester infused with Extreme Pressure (anti-wear additives) &nbsp;Lowers engine temperatures and increases horsepower &nbsp;Longest change intervals &nbsp;For air-cooled / liquid-cooled 4T engines with wet clutches API SM, JASO MA2