dexos is General Motors’ own engine oil specification, and only oils licensed by GM carry it. Most GM gasoline engines call for dexos1 Gen 3. GM says licensed oils are easy to identify: look for the dexos icon on the front label and an 11-character dexos license number on the back. Without both, GM says the oil “is not an authentic, licensed dexos product and is not recommended for use in GM vehicles” (GM, About dexos).
Need the exact grade for your GM vehicle? Look up your vehicle.
Which GM vehicles need dexos?
The owner’s manual names it alongside the viscosity. Two examples:
| Vehicle | Manual requirement |
|---|---|
| 2023 Chevrolet Silverado 1500, 5.3L and 6.2L V8 | Full synthetic oil meeting dexos1, SAE 0W-20 |
| 2024 Chevrolet Colorado, 2.7L turbo | Full synthetic oil meeting dexos1, SAE 5W-30 (SAE 0W-30 below −29 °C / −20 °F) |
Sources: 2023 Silverado 1500 manual, p. 340; 2024 Colorado manual, p. 254. Spec page: Colorado 2.7L.
GM’s manual puts it simply: oils approved by GM as meeting the dexos1 specification “are marked with the dexos1 approved logo,” and owners shouldn’t add anything to the oil, because recommended dexos1 oils “are all that is needed” (Silverado manual, p. 340).
dexos1 Gen 3, dexosR, dexos2 and dexosD
GM’s licensing site explains how the versions relate (GM dexos licensed brands):
| Specification | What GM says |
|---|---|
| dexos1 Gen 3 | Exceeds dexos1 Gen 2 and is backward compatible. Vehicles that used dexos1 or dexos1 Gen 2 “will use a GM dexos 1 Gen 3 or GM dexos R licensed engine oil” of the appropriate viscosity at their next oil change (dexos1 Gen 3 list) |
| dexosR | Meets or exceeds dexos2 and dexos1 Gen 2 and Gen 3, and is backward compatible for gasoline engines (dexosR list) |
| dexos2 | “Replaced by GM dexosD for light-duty diesel engines and GM dexosR for gasoline engines” (dexos2 list) |
| dexosD | For light-duty diesels; meets or exceeds dexos2 and is backward compatible (dexosD list) |
So if your older GM manual says “dexos1,” a current dexos1 Gen 3 oil in the same viscosity is what GM directs you to use.
Which viscosities is dexos1 Gen 3 sold in?
We counted GM’s licensed dexos1 Gen 3 list on October 1, 2026: 1,575 licensed products, of which 815 are 5W-30, 681 are 0W-20, 73 are 5W-20 and 6 are 0W-30 (GM dexos1 Gen 3 list). In other words, dexos1 is a quality standard, not a viscosity; you still need the grade your manual names.
How to check a bottle
- Front label: the dexos icon.
- Back label: an 11-character dexos license number.
- Viscosity: matches your manual (for example, 0W-20 for the Silverado V8s above).
- Optional: search GM’s licensed-brands list for the product name and license number.
“Meets dexos requirements” wording without the icon and license number doesn’t make it a licensed oil. See OEM approved vs. meets requirements.
Frequently asked questions
What is dexos oil?
An engine oil licensed by General Motors to its dexos specification. Licensed oils carry the dexos icon and a license number; GM says unlicensed oils aren’t approved or recommended for GM vehicles.
Is dexos1 Gen 3 backward compatible?
Yes. GM says dexos1 Gen 3 exceeds Gen 2 and is backward compatible, so vehicles that used dexos1 or dexos1 Gen 2 use Gen 3 (or dexosR) of the appropriate viscosity at their next oil change.
Do I have to use dexos oil in my GM vehicle?
Use what your owner’s manual specifies. GM warns that unlicensed oils “could cause engine damage that may not be covered under warranty.”
Is dexos oil synthetic?
GM’s manuals for the vehicles above require full synthetic oil meeting dexos1.
Sources
- General Motors, About GM dexos: licensing, dexos icon and 11-digit license number, unlicensed-oil warning. Accessed October 1, 2026.
- General Motors, dexos1 Gen 3 licensed brands: backward-compatibility note; product counts by viscosity tallied on October 1, 2026.
- General Motors, dexosR, dexos2 and dexosD licensed-brand pages: specification relationships. Accessed October 1, 2026.
- Chevrolet, 2023 Silverado 1500 Owner’s Manual, p. 340: full synthetic dexos1, SAE 0W-20 for the V8s, dexos1 approved logo, no additives. Accessed October 1, 2026.
- Chevrolet, 2024 Colorado Owner’s Manual, p. 254: full synthetic dexos1, SAE 5W-30, 0W-30 in extreme cold. Accessed October 1, 2026.
