AXCL GTi CNG Gas Engine Oil 15W-40 is high performance heavy-duty engine oil for Spark Ignited CNG fueled trucks and buses. It provides excellent performance in the challenging operating environments presented by CNG (Compressed Natural Gas) and offers extended drain interval capability. This product is formulated with premium quality paraffinic base stocks and additive components to provide outstanding lubrication of gaseous fueled engines. The ash content of the oil is minimized to reduce the formation of “hot-spots” that can lead to increased NOx levels and catalyst poisoning.