Gear Oils

Performance characteristics

Selecting the right performance level increases protection for all gear components against wear.

• GL-1 - gear oils without additives for manual transmissions and operating under mild conditions.
• GL-2 - gear oils without additives for manual transmissions and operating under moderate conditions.
• GL-3 - gear oils with a small amount of additives for manual transmissions and operating under moderate conditions.
• GL-4 - high-additive oils for gears operating under moderate to severe conditions or axles with hypoid gears operating under moderate speeds and loads.
• GL-5 - high-additive oils for gears and axles with hypoid gears operating under highly variable conditions. Not suitable for manual gearboxes.
• GL-6 - oils for hypoid gears operating under extreme conditions. Rarely used. Not suitable for manual gearboxes.

Automatic transmissions have highly specific requirements, so performance characteristics of transmission fluids are generally determined by vehicle manufacturers.

Mineral or synthetic

Mineral oils are made from petroleum products; synthetic oils are made from artificially produced chemical compounds. There are two basic types of synthetic gear oils:

• Polyalphaolefins (PAO) - artificial polymeric mineral oils, can be mixed with other mineral oils.
• Polyalkylene glycols (PAG) - cannot be mixed with mineral or PAO oils. Not particularly common in personal vehicles.

Gear oil change intervals are there for a reason

Make sure to follow the car/oil manufacturer’s instructions and change the gear oil as often as they recommend. If you do not have the car manual, contact the car manufacturer or an authorised distributor.