L-605-P-FS Motor Oil CK4 is the most current formulated heavy duty motor oil for all-season use in highway commercial diesel engines, including EGR equipped engine emission controlled systems. The product is manufactured from selected premium quality base stocks with additive technology to provide engine protection for current EPA exhaust particulate emissions standards using Ultra-Low Sulfur Diesel (ULSD). It meets performance requirements for all naturally aspirated, turbocharged and supercharged, diesel engines as well as all four-cycle gasoline engines. The product reflects test improvements in reducing aeration, better oxidation stability, enhanced soot control, and advanced wear protection.