Mobil Rarus™ 400 Series air compressor oils

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Product information

   Mobil Rarus™ 400 Series performance profile 1.753 MB/pdf
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Features and Benefits

The use of the Mobil Rarus 400 Series oils can result in cleaner compressors and lower deposits compared to conventional mineral oils, resulting in longer running periods between maintenance intervals. Their excellent oxidation and thermal stability safely allow extended life capability while controlling sludge and deposit formation. They possess outstanding anti-wear and corrosion protection, which enhances equipment life and performance.
Advantages and Potential Benefits
Low Ash and Carbon Formation Improved valve performanceReduced deposits in discharge linesReduced potential for fires and explosions in discharge systemsImproved compressor performance
Outstanding Oxidation and Thermal Stability Longer oil lifeImproved filter lifeLower maintenance costs
High Load-carrying ability Reduced wear of rings, cylinders, bearings and gears
Excellent Water Separability Less carryover to downstream equipmentReduced sludge formation in crankcases and discharge linesReduced blockage of coalescersLess potential for emulsion formation
Effective Rust and Corrosion Protection Improved protection of valves and reduced wear of rings and cylinders


The Mobil Rarus 400 Series oils are recommended for single and multistage air compressors. They are particularly effective for continuous high temperature operation. The maximum compressed air temperature, according to DIN 51506, is 220 °C. They are suitable for reciprocating and rotary type machines with the lower viscosity grades mainly used in rotary compressors. Rarus 400 Series oils are recommended for units with a history of excess oil degradation, poor valve performance or deposit formation. They are compatible with all metals used in compressor construction and with mineral-oil compatible elastomers used in seals, O-rings and gaskets.

Mobil Rarus 400 Series oils are not intended or recommended for use in air compressors for breathing applications.

The following types of compressors have shown excellent performance with the Mobil Rarus 400 Series oils:

  • Reciprocating air compressor crankcases and cylinders
  • Rotary screw compressors
  • Rotary vane compressors
  • Axial and centrifugal compressors
  • Compressor systems with critical gears and bearings
  • Compressors used in stationary and mobile applications

Specifications and Approvals

Mobil Rarus 400 Series meets or exceeds the requirements of:
DIN 51506 VD-L (1985-09) X X X X X

Typical Properties

Mobil Rarus 400 Series
ISO Viscosity Grade 32 46 68 100 150
Viscosity, ASTM D 445

cSt @ 40º C 32 46 68 104.6 147.3
cSt @ 100º C 5.4 6.9 8.9 11.6 14.7
Viscosity Index, ASTM D 2270 105 105 105 100 100
Sulfated Ash, wt%, ASTM D 874 ‹0.01 ‹0.01 ‹0.01 ‹0.01 ‹0.01
Copper Strip Corrosion, ASTM D130, 3 h @ 100º C 1B 1B 1A 1B 1A
FZG Load Support, DIN 51354, Fail Stage 12 11 12 11 11
Rust Characteristics; ASTM D665 B; ASTM D665 A Pass Pass Pass Pass Pass
Foam Seq I, ASTM D 892 10/0 20/0 0/0 30/0 430/20
Flash Point, ºC, ASTM D 92 236 238 251 264 269
Density @ 15º C, ASTM D 1298 0.866 0.873 0.877 0.879 0.866
  • Cruise and Ferry
  • Specialized Shipping
  • Deep Sea Shipping Industry
  • Inland and Coastal
  • Offshore Supply Vessels
  • Short Sea Shipping
  • Extended Life
  • Synthetic
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