What is the GM recommended oil?
GM's current guidance is to use engine oil that meets the Dexos specification; for most gasoline engines built since roughly 2011, that means Dexos1 Gen 2 oil, with the viscosity (commonly 0W-20 or 5W-30) specified in the owner’s manual. For older GM vehicles, Dexos1 Gen 1 or conventional oils meeting GM specs may apply. Always check your vehicle’s manual or with a GM dealer to confirm the exact requirement.
What Dexos means for GM engines
Dexos is GM’s engine oil specification designed to improve engine protection and emissions performance. Oils that meet Dexos1 Gen 2 have passed GM-specific testing and are aligned with warranty requirements when used as directed in the owner's manual. Using non-Dexos oil can affect warranty eligibility and engine wear protection.
Dexos versions and where they apply
To understand which Dexos version applies to your GM engine, here is a quick guide to the main generations in common use.
- Dexos1 Gen 2 — the current Dexos specification for most gasoline engines in GM vehicles built from about 2011 onward. Oils labeled Dexos1 Gen 2 are designed to meet GM's needs for modern engines and are typically paired with 0W-20 or 5W-30 viscosities, depending on the model and climate.
- Dexos1 Gen 1 — the earlier Dexos standard used by older GM gasoline engines; if your vehicle predates the Gen 2 rollout, look for Dexos1 Gen 1 compliance or a GM-specified viscosity.
- Dexos2 — a specification used for diesel engines and some European-market GM vehicles; ensure your engine requires Dexos2 and that the oil carries that certification.
In practice, always consult the owner's manual or a GM dealer to confirm the exact Dexos version and viscosity specified for your model and driving conditions.
Common GM viscosity recommendations for Dexos oils
Aside from the Dexos certification, the viscosity grade is the other key variable. The exact grade your engine requires is printed on or near the oil fill cap and in the owner's manual. Here are the two most common choices you’ll encounter in modern GM vehicles.
- 0W-20 — Widely recommended for many newer GM gasoline engines for improved fuel economy and cold-start performance.
- 5W-30 — Used by some engines or climates where additional high-temperature protection is needed.
Always verify the specific grade for your vehicle, as incorrect viscosity can affect performance and warranty coverage.
How to buy the right GM-approved oil
To ensure you purchase the correct GM-approved oil, follow these steps:
- Check your owner's manual for the exact Dexos specification (Gen 1, Gen 2, or Dexos2) and the advised viscosity.
- Look for Dexos branding on the oil container; choose a product that explicitly lists the required Dexos specification.
- If in doubt, ask a GM service advisor or dealership to confirm the correct oil for your specific model and engine.
Using oils that meet GM’s Dexos specification helps protect warranties and ensures your engine receives the appropriate protection and performance.
Summary
GM recommends using Dexos-certified engine oil to meet GM’s testing and warranty standards. For most modern GM gasoline engines, Dexos1 Gen 2 is the standard, typically paired with a viscosity of 0W-20 or 5W-30 as specified by the vehicle’s manual. Older GM engines may use Dexos1 Gen 1 or conventional oils that meet GM specifications, and diesel or some European models may require Dexos2. Always consult the owner’s manual or a GM dealership to confirm the exact Dexos version and viscosity for your vehicle.
