Mobil Pegasus 605 Ultra 40

Mobil Pegasus™ 605 Ultra 40

Gas Engine Oil

Mobil Pegasus 605 Ultra 40 is formulated primarily to lubricate modern medium-speed and high-speed four-cycle engines operating on landfill and biomass gas. Operations can rely on this outstanding lubricant to help provide:

  • Very long oil life (up to 1,000 hours between drain intervals)
  • Wear, deposit and varnish control
  • Enhanced spark plug performance
  • runtime

    Enhanced engine availability due to very long oil drain intervals and long filter life

  • oil drop

    Exceptional engine cleanliness despite the contaminants common to landfill and biomass gasses

  • gears

    Minimized component wear and scuffing on liners

  • power and energy savings

    Minimized power loss from detonation

Equipment lubricant recommendations

Our Mobil Serv℠ Product Selector tool will help you identify lubricant(s) for your specific equipment.

Data sheets

Product information

Features and Benefits

•  Exceptional oxidation stability, nitration resistance and thermal stability that help extend oil life, clean engines, reduce filter costs and resist deposit formation

•  Very good anti-wear characteristics help to reduce wear of engine components, reduce scuffing of liners in highly loaded gas engines and provide break-in protection

•  Extraordinary detergent-dispersant system provides protection of upper cylinder and valve train components, clean engines and long filter life

•  Optimized TBN and reserve alkalinity help protect valve seats and faces on four-cycle engines, improve spark plug performance, and reduce power loss from detonation



     •  Engines operating on fuel containing corrosive materials such as THCl (Total Organic Halides as Chloride) such as landfill or biomass gas

     •  Gas engines operating on fuel that contains moderate levels of hydrogen sulfide (H2S)

     •  Spark ignited four-cycle gas engines with very low lube oil consumption

     •  Medium and high speed four-cycle engines equipped with catalytic converters requiring a low ash gas engine oil

     •  Reciprocating compressors operating on natural gas that contains sulphur or chlorine compounds


Specifications and Approvals

This product has the following approvals:

INNIO Waukesha Engine Landfill Gas Applications

MWM TR 0199-99-2105, Lube Oils for Gas Engines

INNIO Jenbacher TI 1000-1109 (Class B fuel gas, Type 2 & 3)

INNIO Jenbacher TI 1000-1109 (Class B fuel gas, Type 4A, 4B & 4C)

INNIO Jenbacher TI 1000-1109 (Class B fuel gas, Type 6 up to version E)

INNIO Jenbacher TI 1000-1109 (Class C fuel gas, Type 2 & 3)

INNIO Jenbacher TI 1000-1109 (Class C fuel gas, Type 4A & 4B)

INNIO Jenbacher TI 1000-1109 (Class C fuel gas, Type 6 up to version E)

Caterpillar Energy Solutions TR 2105, Lube Oils for Gas Engines (CG132, CG170, CG260)

MAN M 3271-4

INNIO Jenbacher TI 1000-1109 (CAT (catalyst) approved)

INNIO Jenbacher TI 1000-1109 (Class C fuel gas, Type 4A, 4B & 4C) 

Rolls-Royce Solutions Augsburg (former MTU Onsite Energy) Gas Engine Series 400 - all engines operated with SCR catalyst and cleaned biogas (from digestion or sewage gas) and cleaned landfill gas 

MAN M 3271-5 
MTU Gas Engines Series 4000 L62FB and L32FB using biogas with a reduced power output of 83kW/cyl. electr.


This product meets or exceeds the requirements of:



Properties and Specifications




SAE 40

Ash, Sulfated, mass%, ASTM D874


Density @ 15.6 C, kg/l, ASTM D1298


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


Viscosity Index, ASTM D2270


Base Number - Xylene/Acetic Acid, mg KOH/g, ASTM D2896 (*)


(*) use of other ASTM approved solvents may yield different results

Health and safety

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

  • Corrosion protection
  • Enhanced wear protection
  • Oxidation resistance
  • Wide temperatures
  • Gas engine oils - by OEM

Technical resources