ARB Air Locker differentials are constructed entirely from premium grade materials that meet or exceed automotive (SAE) and most military (MIL) and aerospace standards for resistance to commercially available lubricant grades and additives. As such, Air Lockers have no special requirements for lubricants above those which would be recommended according to the climate you live in and the nature of how you use your vehicle, and so the specifications below are provided only to assist in finding a suitable gear oil to suit. However, ARB does not suggest the use of oil that contains limited-slip additives as they can shorten the life of the Air Locker seals.
| Climate | Harshest Nature of Intended Vehicle Use | ||
| Light to Medium Domestic/Predominantly On Road | Recreational Enthusiast/Light Commercial | Heavy Recreational/Motorsport/Industrial | |
| Temperate | API GL-5 90 weight mineral based gear oil | API GL-5 90 to 140 weight synthetic or semi-synthetic EP gear oil. | API MT-1 or SAEJ2360 140 weight full synthetic. |
| Subtropical | API GL-5 90 weight mineral based gear oil | API GL-5 90 to 140 weight mineral, synthetic or semi-synthetic EP gear oil. | API MT-1 or SAEJ2360 140 to 250 weight full synthetic. |
| Tropical | API GL-5 140 weight mineral based gear oil | API GL-5 140 weight mineral, synthetic, or semi-synthetic EP gear oil. | API MT-1 or SAEJ2360 140 to 250 weight full synthetic. |