Specially formulated for spark-ignited CNG- and LNG-fueled truck and bus engines, Mobil Delvac CNG/LNG 15W-40 is a high-performance, heavy-duty engine oil with excellent thermal stability and oxidation control. Mobil Delvac CNG/LNG 15W-40 offers exceptional wear protection as well as highly effective detergency and dispersancy properties for a clean running engine in the demanding applications using Compressed Natural Gas (CNG) and Liquefied Natural Gas (LNG). This product provides extended drain interval capability for spark-ignited CNG-/LNG-fueled stoichiometric and lean-burn engines, and is compatible with Exhaust Gas Recirculation (EGR) systems, three-way catalysts and other emissions reduction systems. The optimized ash level helps prevent spark plug fouling and excessive valve recession. Mobil Delvac CNG/LNG 15W-40 meets or exceeds the requirements of Cummins CES 20085 and Isuzu CNG Engine Oil, and is approved by Detroit Fluids Specification 93K216.