Mobil GEO 15W-40

Premium Natural Gas Engine Oil

Mobil GEO 15W-40 is a premium fleet engine oil specifically formulated to provide reliable protection for trucks and buses using Compressed Natural Gas (CNG) or Liquefied Natural Gas (LNG). Mobil GEO 15W-40 is formulated from high quality base stocks and a balanced additive system. This advanced medium ash formulation provides excellent oxidation, nitration, and thermal stability to minimize combustion chamber ash deposits. Mobil GEO 15W-40 lubricates with less varnish, sludge, and carbon build-up under the most severe operating conditions.



Features and Benefits

Modern high output, high speed, lean-burn diesel type engines using natural gas fuels place severe demands on engine lubricants. Mobil GEO 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



Recommended by ExxonMobil for use in:

     •  Spark ignited CNG and LNG-fueled lean-burn engines

     •  Dual fuel engines using diesel fuel for start-up and 15% diesel pilot fuel with CNG/LNG

     •  On-highway light and heavy-duty trucks and busses


Specifications and Approvals

This product meets or exceeds the requirements of:

Cummins CES 20074


Properties and Specifications



SAE 15W-40

Ash, Sulfated, mass%, ASTM D874


Density @ 15.6 C, g/ml, ASTM D4052


Flash Point, Cleveland Open Cup, °C, ASTM D92


Kinematic Viscosity @ 100 C, mm2/s, ASTM D445


Kinematic Viscosity @ 40 C, mm2/s, ASTM D445


Pour Point, °C, ASTM D97


Total Base Number, mgKOH/g, ASTM D2896


Viscosity Index, ASTM D2270



Health and safety

Health and Safety recommendations for this product can be found on the Material Safety Data Sheet (MSDS) @