Citgo Citgard 700 15W40 Heavy Duty Engine Oil is a synthetic blend product that meets or exceeds the API CK-4 heavy duty requirements. This product is made to be used for engines using ultra low sulfur diesel fuel. It provides advanced soot control, exceptional oxidation and thermal protection for operating at extreme temperatures. It is recommended for use in heavy duty commercial trucks, agricultural equipment, construction equipment and other diesel fueled engine applications. It also has state of the art wear control technology for reduced wear.