GM have had oil standards for engine oils and gear oils for some time, covering most cars sold under the Vauxhall and Opel brands plus - worldwide - Buick, Cadillac, Chevrolet, GM Daewoo, GMC, Holden, Hummer, Pontiac, Saturn and more recent Saab models. The most popular engine oil specifications are the GM LL-A-025 and LL-B-025 specifications plus the new dexos2™ specification. For gear oils, Dexron is GM's standard; oil manufacturers buy a licence to produce oil to the Dexron specification from GM. There is also a wide variety of different GM automatic transmission fluid specifications. Opie Oils sells oils manufactured to the GM oil specifications; Opie Oils is not a licensed GM dealer or repair...
Engine oils meeting the General Motors / Vauxhall / Opel engine oils specifications are listed here, available to buy online from Opie Oils for retail and trade purchase with delivery to your home, workplace or workshop.
Gear oil and automatic transmission fluids meeting the various GM gear oil and ATF specifications are listed below under their respective standard numbers. DEXRON® is GM's main ATF standard; oil manufacturers buy a licence to produce oil to the DEXRON®- specification from GM. DEXRON®-VI is the current and only official standard; earlier DEXRON® standards are no longer licensed by GM and therefore not regulated by them in any way.
Opie Oils sells oils manufactured to the GM ATF and gear oil specifications; Opie Oils is not a licensed GM dealer or repair centre.