UNDERSTANDING
GM DEXOS®
Dexos is General Motors' own engine oil quality standard — GM's private quality seal, similar to how BMW has Longlife-04 or Mercedes-Benz has MB 229.51. If your vehicle's owner manual specifies a dexos® oil, using a licensed dexos® product is the safest way to protect your engine warranty.
GM's Private Quality Seal
Dexos is not a marketing claim — it is a licensed quality standard backed by real engine tests conducted or overseen by General Motors. Only lubricant manufacturers who have passed GM's rigorous testing programme and paid for the licence can display the dexos® name and logo.
This matters because the engine oil market is full of products that claim to meet dexos® standards without ever having been tested or licensed. Using such an unlicensed product can void your GM manufacturer warranty and leave your engine unprotected.
Wolf Oil Corporation holds three simultaneous active GM dexos® licences — one of the few independent lubricant manufacturers in Europe to achieve this breadth of coverage.
Three Active dexos® Specifications
There are currently three active dexos® specifications relevant to European users. Understanding which one applies to your vehicle is the key to correct oil selection.
The latest GM petrol engine oil standard. In Europe, mostly relevant for North American-spec GM vehicles (Chevrolet, Cadillac, Buick) brought into Europe. Opel and Vauxhall petrol engines now follow the Opel OV 040 1547 specification instead. Broadly comparable to ACEA A5/B5 — a low-viscosity, fuel-economy-focused petrol oil.
GM's essential European specification covering both petrol and diesel engines — the standard for Opel, Vauxhall, Saab, and European Chevrolet from Model Year 2010 onwards. Built on ACEA C3. Fully supersedes GM-LL-A-025 and GM-LL-B-025. dexos2™ remains active and is the correct specification for most Opel engines. WOC MO-001 carries BOTH dexos2™ AND dexos®D — dual-approved.
GM's dedicated diesel specification — an additional approval on top of dexos2™. WOC MO-001 carries BOTH dexos2™ AND dexos®D, making it the dual-approved flagship for European Opel diesel engines. dexos®D is built on ACEA C5/C6 and adds an extra layer of diesel-specific certification for the most modern DPF and SCR aftertreatment systems.
Side-by-Side Comparison
For a European workshop or distributor, the choice is straightforward once you understand the three specs.
| Feature | dexos1™ Gen 3 | dexos2™ | dexos®D |
|---|---|---|---|
| Petrol engines | Yes | Yes | No |
| Diesel engines | No | Yes | Yes |
| ACEA base | A5/B5 | C3 | C5/C6 |
| Typical viscosity | 0W-20/5W-30 | 5W-30/5W-40 | 0W-20 |
| DPF/SCR protection | Standard | Good | Excellent |
| European relevance | Low | Essential | Additional (diesel) |
| Status | Active | Active | Active |
The Simple Rule for a European Workshop
The dexos® Evolution Timeline
From the first dexos1™ specification in 2011 to the current dexos®D and OV 040 1547 standards, the GM specification landscape has evolved significantly. Click any entry to expand details.
3 Active GM dexos® Licences
WOC is one of the few independent lubricant manufacturers to hold simultaneous licences across three dexos® specifications. This breadth of coverage means a single WOC partner can serve the entire GM vehicle parc — from the latest Opel diesel to North American GM gasoline engines.