Modern high output, high speed, lean-burn diesel type engines using natural gas fuels place severe demands on engine lubricants. Mobil Gas Engine Oil 15W-40 is formulated to strict standards to deliver reliable engine performance in modern diesel type engines using natural gas as the primary fuel. The key benefits include: High thermal and oxidation stability helps control sludge build-up and deposits Reserve TBN neutralizes oxy acids and nitrates to reduce deposits Shear stability reduces oil consumption and provides bearing wear and cylinder liner scuff protection Effective detergency/dispersancy keeps engines cleaner Low levels of Zinc and Phosphorous help extend catalytic converter life