Mobil Pegasus 505

Gas Engine Oil

Mobil Pegasus™ 505 Series are natural gas engine oils formulated exclusively from specially selected base stocks of high stability. These lubricants provide the excellent performance and economy for a wide variety of engine types, service severity and fuel qualities.


Mobil Pegasus 505 and 505 SAE 30 utilize advanced technology to provide excellent detergency/dispersency protection characteristics along with high-temperature anti-scuff and anti-scoring protection. These oils contain ashless and metallic detergents and are fortified with oxidation inhibitors and antiwear agents. Their use helps minimise carbon and ash deposits.


Mobil Pegasus 505 Series oils combat corrosive wear in cylinders and bearings by neutralising acids. They will also minimize wear of rings, liners and bearings and will help curtail wear in valve seats of turbocharged, four-cycle gas engines. These oils provide good engine cleanliness and filter life.


Features and Benefits

Mobil Pegasus 505 Series gas engine oils provide clean engines, low wear rates and improved engine performance. The result is the potential for reduced maintenance costs and improved production capacity. Its good chemical and oxidation stability allows for extended drain intervals and filter cost reduction.



Advantages and Potential Benefits

Outstanding Anti-wear and Anti-scuff Properties

Lower wear of engine components

Reduced scuffing of liners of highly loaded gas engines

Provides excellent break-in protection of high BMEP engines

Good Oxidation and Bulk Oil Stability

Cleaner engines

Good oil life

Reduced filter costs

Good resistance to oxidation and nitration

Resists coking and formation of undercrown deposits

Low Ash Formulation

Protects valve seats and faces on four-cycle engines

Controls combustion chamber ash formation and improves spark plug performance

Less power loss from detonation caused by combustion chamber deposits

Good Corrosion Resistance

Protects bearings and internal components

High Quality Basestocks

Reduced port blockage, with longer intervals between cleaning



     •  Crankcases and power cylinders of spark-ignited two- and four-cycl gas engines

     •  Highly loaded 4-cycle engines requiring anti-scuff protection

     •  Reciprocating compressor cylinders compressing natural gas

     •  High output naturally aspirated or turbocharged engines

     •  Recommended for engines requiring 0.5% sulfated ash

     •  Has been successfully used in:


                 Dresser Rand

                 Fairbanks- Morse





Properties and Specifications



SAE 40

Ash, Sulfated, mass%, ASTM D874


Density 15 C, kg/L, CALCULATED


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) @