Gas Engine Oil

Mobil Pegasus™ 805 is premium performance gas engine oil engineered to meet the rigorous demands of today’s high output four-cycle engines designed to reduce emissions and improve fuel-efficiency. These gas engines generally operate under high load and high temperature conditions. Mobil Pegasus 805 is made from high quality base stocks and an advanced technology additive system that provides exceptional oxidation stability, nitration resistance and thermal stability. Its detergent and dispersant system controls the formation of carbon deposits, lacquer and sludge resulting in cleaner engines, longer oil life and reduced filter costs.

Mobil Pegasus 805 is also designed to provide exceptional protection against piston scuffing, scoring and ring and liner wear. It exhibits excellent resistance to foaming, good demulsibility and protection against corrosion. It is formulated with very low levels of zinc and phosphorus making it compatible with engines equipped with catalytic converters.

Features and Benefits

Mobil Pegasus 805 is designed to provide optimum engine life and low maintenance costs. It meets a wide range of OEM requirements making it an excellent choice where high-speed four-cycle engines from various OEMs are used. Its unique innovative technology allows for control of valve train component wear and reduces the potential for scuffing, scoring and accelerated piston and ring wear. The end result is lower costs of operating and maintaining your gas engines.

Features Advantages and Potential Benefits
Exceptional Oxidation and Nitration Resistance Cleaner engines

Longer oil and filter service

Improved engine performance

Outstanding Anti-wear and Anti-scuff protection Reduced scoring, scuffing and wear of pistons and liners

High level of protection in fully loaded engines

Reduced maintenance costs

Advanced Technology Additive System Excellent protection of valve train components

Reduced levels of combustion chamber ash

Improved spark plug life

Very Effective Corrosion Protection Protects internal engine components from water, coolant and acidic materials

Neutralizes acids formed from combustion or oil degradation

Excellent Detergent / Dispersancy Performance Protects valve train components

Reduces ash and carbon deposits in combustion chambers

Improves spark plug life and performance

Reduces filter replacement costs


• Caterpillar, Superior, Waukesha and other turbocharged, naturallyspirated, medium to high speed four-cycle engines requiring a low ash oil

• Engines experiencing valve face and seat wear

• Lean-burn and stoichiometric four-cycle engines

• Engines equipped with catalytic converters

• Applications using alternate fuels containing low levels of sulfur or chlorine

• In field gathering operations where sour gas (low levels of H2S) is used as fuel

Specifications and Approvals

This product has the following approvals:
Caterpillar Energy Solutions TR 2105, Lube Oils for Gas Engines (CG132, CG170, CG260)
INNIO JENBACHER TI 1000-1109 (Class A fuel gas, Series 2, 3, 4 & 6)
INNIO JENBACHER TI 1000-1109 (Class B fuel gas, Series 4 & 6)
GE Waukesha Engine 12V/18V 220 GL Applications Using Pipeline Quality Gas
GE Waukesha Engine Cogeneration Applications Using Pipeline Quality Gas
MAN Energy Solutions Augsburg (Heritage MAN B&W) 4 Stroke medium speed engines for LNG operation
MTU MTU Gas Engines S4000 L61, L62, L63, L64 using natural gas
MTU Onsite Energy Series 400 Gas Engines
MWM GmbH TR 0199-99-2105


This product meets or exceeds the requirements of:

Properties and Specifications

Grade SAE 40
Ash, Sulfated, mass%, ASTM D874 0.5
Flash Point, Cleveland Open Cup, °C, ASTM D92 262
Kinematic Viscosity @ 100 C, mm2/s, ASTM D445 13.5
Kinematic Viscosity @ 40 C, mm2/s, ASTM D445 130
Pour Point, °C, ASTM D97 -12
Specific Gravity, 15.6 C/15.6 C, ASTM D4052 0.89
Total Base Number, mgKOH/g, ASTM D2896 6.2
Viscosity Index, ASTM D2270 99
Foam, Sequence I, Tendency, ml, ASTM D892 0
Foam, Sequence I, Stability, ml, ASTM D892 0

Health and safety

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



It cannot be guaranteed that the product information given above is up to date. For the latest version of the Product Data Sheet we refer to the product library of ExxonMobil.