A. Yes. Most leading diesel engine manufacturers typically recommend engine oils that are specifically designed and formulated for engines using CNG or LNG. Oils, referred to as "Fleet Oils" or oils designed to be used in diesel fueled engines are generally not recommended. One of the leading engine manufacturers has reported that "Valve Torching" can result from using the fleet oils in the lean burn conditions of CNG fuel engines. It is understood that stocking only one product is more desirable in mixed diesel and CNG fleets, but it is highly recommended that the equipment owner consult with the engine manufacturer and find out their engine oil recommendations before settling on the "One Oil" for both diesel and CNG engines.