Mobilube HD Extra 80W-140

High Performance Commercial Gear Lubricants

Mobilube™ HD Extra MG 75W is a high performance commercial gear lubricant formulated from select base oils and an advanced additive system. This lubricant is engineered for performance in heavy-duty commercial manual transmissions, axles, and final drives where severe service with shock loading is expected. It provides an excellent chemical and thermal stability at elevated bulk oil temperatures, good performance at low temperatures, and good rust protection resulting from water contamination and wet conditions. It will provide excellent performance in applications where API GL-6 (Mobilube HD Extra 80W-140) or GL-6/GL-5 (Mobilube Extra MG 75W) lubricants are required. API GL-6 denotes lubricants intended for gears with very high pinion offset where protection from gear scoring in excess of that provided by GL-5 lubricants is required. API GL-6 is no longer active as the original test equipment and procedures are obsolete.


Equipment lubricant recommendations

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

Data sheets

Features and Benefits

Today's heavy equipment applications place higher performance demands on drive train lubricants. Higher speeds, higher torque, and heavier loads require improved formulations to maximize equipment life and optimize operating costs. Longer service intervals place additional demands on the gear lubricant. Mobilube HD Extra gear lubricants are engineered to meet these challenges. The key benefits include:



Advantages and Potential Benefits

Excellent thermal stability and resistance to high temperature oxidation

Extended gear and bearing life due to minimal deposits and longer seal life

Good protection against low speed/high torque wear and against high speed scoring

Increased load carrying capability and reduced operating costs

Excellent rust, staining, and corrosion protection

Reduced wear and longer component life

Effective low temperature lubrication

Reduced wear and ease of start-up

Wide multipurpose capability

Reduced number of gear lubricants to simplify inventory and minimize misapplication

Good resistance to foaming

Maintains film strength for effective lubrication

Compatible with typical automotive seals and gaskets

Minimum leakage and reduced contamination



     •  Heavy-duty manual transmissions, axles, and final drives requiring API GL-6 (inactive) or GL-5 level performance

     •  On-highway light and heavy-duty trucks, busses, vans, and cars

     •  Off-highway industries including: construction, mining, quarrying, and agriculture

     •  Other heavy-duty industrial and automotive applications involving hypoid and other gears operating under conditions where high speed/shock load, high speed/low torque, and/or low speed/high torque conditions prevail

     •  Mobilube HD Extra gear lubricants are intended for top-off, and refill of enclosed commercial gearing in manual or semiautomatic transmissions where gear lubricants are recommended including drive axles and final drives

     •  Not recommended for applications requiring API GL-4 Level performance

     •  Not intended for transmissions for which engine oil or automatic transmission fluids are recommended


Specifications and Approvals

This product is recommended for use in applications requiring:

MG 75W






Properties and Specifications


MG 75W



Density @ 15 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


Viscosity Index, ASTM D2270



Health and Safety

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