What is hypoid gear oil?

Hypoid oil is an automotive oil used to lubricate gears in engines that have a hypoid design. Hypoid oil provides advanced protection to the gears, which are meshed at 90 degree angles in a hypoid engine, causing high pressure and increased strain.

Hypoid oil is similar to gearbox oil used in transmissions and machinery, but has additives mixed in to reduce wear caused by the extreme temperatures and pressure of the hypoid design. The hypoid design is more efficient and produces less noise than previous gear designs and is the standard vehicle transmission design in almost all vehicles, as of 2015.