Dexos Approved Oil Lists [Dexos 1, Dexos 2, Dexos 3, Dexos D, Dexos R]

GM’s Dexos specifications are proprietary standards that exceed conventional industry benchmarks like API and ILSAC. Understanding the differences between them matters because using the wrong spec can affect your warranty and engine longevity.

Dexos 1 is the core standard for GM gasoline engines built after 2011, requiring synthetic or synthetic blend oils. Gen 1 (2010, now obsolete) established the baseline. Gen 2 (2015, obsolete) added critical Low-Speed Pre-Ignition (LSPI) protection for turbocharged engines. Gen 3 (2021, current) is the highest gasoline standard, available in 0W-20 and 5W-30, with stricter requirements for oxidation resistance, sludge control, turbo protection, and fuel economy retention.

Dexos 2 was developed for light-duty diesel and European gasoline engines, including the U.S.-spec C8 Corvette. It emphasized soot control and required 3.5 mPa·s HTHS viscosity in 5W-30 and 5W-40 grades. 

Dexos D (2019) replaced Dexos 2 for modern Duramax diesels like the 3.0-liter LM2, focusing on 0W-20 viscosity for fuel economy. Keep in mind that Dexos 2 oils are not suitable for Duramax diesels.

Dexos R is the premium standard for high-performance engines in the Corvette, Camaro ZL1, and Cadillac V-Series, using thicker 0W-40 and 5W-50 grades for extreme conditions. 

Some vehicle owners may mistakenly say Dexos 3. When they do, they’re probably referring to Gen 3, the third generation of Dexos 1.

Dexos 1 Gen 3 Approved Oil List

Dexos 1 Gen 3: 5W30 Approved Oil List

Dexos 1 Gen 3: 5W20 Approved Oil List

Dexos 1 Gen 3: 0W20 Approved Oil List

Dexos 1 Gen 3: 0W30 Approved Oil List

Dexos 2 Approved Oil List

Dexos 2 5W40 Approved Oil List

Dexos 2 5W30 Approved Oil List

Dexos 2 0W40 Approved Oil List

Dexos D Approved Oil List

Dexos R Approved Oil List

What Is Dexos Oil

GM’s Dexos specifications are proprietary standards that go beyond conventional API and ILSAC benchmarks, with each one engineered for specific engine types and driving conditions. 

Dexos 1 is GM’s core specification for gasoline engines, and it’s evolved through three generations to meet increasingly demanding requirements.

Using substandard oil can damage your engine. Only licensed Dexos® products meet GM’s specifications and rigorous testing. Unlicensed oils lack certification and quality control, risking performance issues and potential engine damage not covered by warranty.

Genuine Dexos® products are easy to identify with the Dexos® icon on the front label and an 11-digit license number on the back. Avoid oils without these markings to ensure compatibility with GM vehicles.

Dexos 1

GM engineered Dexos D for light diesel engines, making it ideal for 0W-20 viscosity oil in models from 2020 onwards. It meets high standards and enhances efficiency, effectively replacing Dexos 2 for diesel engines. Note: Dexos 1 has been updated to Dexos 1 Gen 3.

Dexos 1 is GM’s core specification for gasoline engines, and it’s evolved through three generations to meet increasingly demanding requirements.

Dexos 1 Gen 1 (now obsolete) established the baseline with synthetic or synthetic blend formulations, better antioxidant technology, and improved viscometric properties. It reduced friction and enhanced aeration control compared to standard synthetic oils. The spec was originally developed around 0W-20, though 5W-30 was also available.

Dexos 1 Gen 2 (also obsolete) brought a critical addition: Low-Speed Pre-Ignition (LSPI) prevention. LSPI is a destructive phenomenon in smaller turbocharged engines where fuel ignites prematurely at low RPMs under high load. Gen 2 also improved oxidation resistance, deposit control, and included aeration resistance testing for Variable Valve Timing (VVT) systems. It remained backward compatible with Gen 1.

Dexos 1 Gen 3 (current standard) demands stricter standards across the board: tighter oxidation resistance, improved sludge control, higher turbocharger protection, better fuel economy retention, and enhanced chain wear resistance. 

GM replaced their legacy fuel economy and LSPI tests with more demanding versions. Available in 0W-20 and 5W-30, Gen 3 oils are backward compatible with Gen 2 and addresses the specific challenges of modern turbocharged, direct-injection gasoline engines.

Dexos 2

Dexos 2 was developed for light-duty diesel engines and certain European-market gasoline engines. Dexos 2 requires a high-temperature, high-shear (HTHS) viscosity of at least 3.5 mPa·s. This matters because diesel combustion runs hotter than gasoline, and the oil needs to maintain its protective film under that extreme heat and pressure.

Soot control separates Dexos 2 from gasoline specs. Diesel combustion produces soot that contaminates the oil, turning it black almost immediately. Dexos 2 includes air entrainment (forming bubbles) and soot dispersion tests to ensure the oil can handle this. When soot content hits 2.5%, viscosity increase must stay under 6 mm²/s at 100°C. This requirement is needed to make sure that bearings and other critical components get proper lubrication in these conditions.

Emissions compatibility shaped the formulation. Dexos 2 uses Low SAP (Sulfated Ash, Phosphorus, and Sulfur) chemistry to protect Diesel Particulate Filters (DPFs) and extend catalyst life. Modern emission systems are expensive and sensitive. Certain chemical additives will clog or poison them, so Dexos 2 restricts those compounds.

Dexos 2’s enhanced oxidation resistance and wear protection allowed drain intervals of one year or 10,000 kilometers. You’d typically find Dexos 2 in 5W-30 and 5W-40 grades.

Dexos D

Dexos D replaced Dexos 2 specifically for light-duty diesel applications like the 3.0-liter Duramax. The primary focus remains diesel engines with exhaust treatment devices, maintaining Low SAP requirements for DPF protection. However, Dexos D emphasizes low viscosity, primarily the 0W-20 oil, to improve fuel economy.

Very important: Dexos 2 oils are not suitable for Duramax diesels requiring Dexos D. Some Dexos 2 oils that also meet ACEA C3 might eventually be considered acceptable equivalents until (at least until Dexos D 5W-30 becomes widely available). However, it’s still best to check your owner’s manual.

Dexos R

Dexos R is GM’s newest specification, uniquely engineered for high-performance and track use in vehicles like the Corvette and Camaro ZL1.

The primary use case is high-speed, high-load, and high-temperature conditions that come with aggressive driving. Think track days, canyon runs, and sustained high-RPM operation.

Dexon R’s thicker, more robust oils (0W-40 and 5W-50) protect engines under extreme mechanical stress that would shear down lighter oils.

Dexos R oils meet or exceed the performance of Dexos 2 and Dexos 1 Gen 2/Gen 3. This means vehicles requiring those older specs can use a Dexos R oil of the appropriate viscosity grade. However, this doesn’t work in reverse. Dexos R is a separate specification from Dexos 1 Gen 3, and you should not substitute Dexos 1 Gen 3 if your owner’s manual calls for Dexos R.

Dexos 1 Gen 3 vs Dexos 2 vs Dexos D vs Dexos R: What Are The Differences?

Here are the significant comparisons of the different Dexos generations to further understand the oil.

	Dexos 1 Gen 3	Dexos 2	Dexos D	Dexos R
Application	– Gasoline engines – Focuses on Asian and North American Region	– Diesel engines, and a few gasoline engines  in Euro – Focuses on European Region	– Light-duty diesel engines – Used for late model GM vehicles with diesel engines that require 0W-20 engine oil	– Gasoline engines – Meets or exceeds the performance of Dexos 1 Gen 2 and Gen 3 oils
Model Year	– Apply for 2011 model year vehicles	– Apply for 2010 model year vehicle	– Apply for 2020 model year diesel vehicles	– Backward compatible with vehicles using Dexos 2, Dexos 1 Gen 2, or Gen 3
Specifications	– Meets ILSAC GF-5 & API SN Service Classification	– Meets API SN and ACEA C2/A5/B5 Service Classification	– Meets API SN and ACEA C5	– Meets or exceeds the performance of Dexos 2 and Dexos 1 Gen 2 and Gen 3 oils

Application

GM specifically formulated Dexos 1 for gasoline engines in North America and Asia. Dexos 2 is designed for both diesel and gasoline engines in Europe, while Dexos D is ideal for light-duty diesel engines needing 0W-20 viscosity oil globally.

Dexos 1 suits models from 2011 onwards, Dexos 2 is for 2010 model year engines, and Dexos D targets modern engines from 2020 onwards.

Specifications

Before releasing Dexos oils to the market, GM conducts numerous tests and certifications to ensure they meet all requirements and are safe for use both at home and on the road.

Dexos 1 meets ILSAC GF-5 & API SN Service Classification; Dexos 2 meets API SN and ACEA C2/A5/B5 Service Classification, while Dexos D meets API SN and ACEA C5 certifications.

Key Features

All Dexos oils share some common features, including being full synthetic or synthetic blend, longer change intervals compared to conventional counterparts, and outstanding temperature control. However, each type of Dexos oil also has unique characteristics that make it ideal for specific applications.

Frequently Asked Questions

Are Dexos 1 and Dexos 2 interchangeable?

No, Dexos 1 and Dexos 2 are not interchangeable. Dexos 1 is designed exclusively for gasoline engines with features like Low-Speed Pre-Ignition (LSPI) prevention, while Dexos 2 uses a low-SAPS formulation for diesel engines and emission-controlled systems like Diesel Particulate Filters (DPFs).

Why do the Dexos standards keep changing?

GM updates Dexos standards to address evolving engine technology like turbocharging and Gasoline Direct Injection (GDI), while meeting stricter fuel economy and emissions regulations. 

Which Dexos is for diesel?

Dexos D is the current standard for light-duty diesel engines like the Duramax 3.0 liter, replacing the phased-out Dexos 2 specification. Heavy-duty Duramax engines requiring API CJ-4 oil should use that specification instead of Dexos D.

What grades does Dexos R cover?

Dexos R covers 0W-40 and 5W-50 viscosity grades. This premium standard is designed for high-performance GM engines like those in the Corvette and Camaro.

What oil viscosity is Dexos D?

Dexos D is a 0W-20 specification. This low-viscosity diesel oil reduces fluid drag for improved fuel economy in modern light-duty diesel engines equipped with exhaust treatment devices.

When did Dexos standards change?

The timeline runs from 2010 (Dexos 1 Gen 1 and Dexos 2), 2015 (Gen 2 with LSPI protection), 2019-2020 (Dexos D for diesels), 2021 (Gen 3 for gasoline), to 2023 (Dexos R for high-performance). Newer standards like Gen 3 are backward compatible with previous generations, while Dexos R meets or exceeds all prior Dexos specifications when the correct viscosity is used.

• Dexos 1 Gen 3: Withstands high temperatures, keeping engines well-lubricated and running smoothly even in extreme heat.
• Dexos 2: Offers enhanced cleaning and wear protection, extending engine life for diesel and some gasoline engines in Europe.
• Dexos D: Provides low viscosity and friction, protecting against wear, improving fuel economy, and suited for light-duty diesel engines and 0W-20 GM vehicles.
• Dexos R: Outperforms Dexos 1 Gen 2 and Gen 3, offering exceptional protection and performance for gasoline engines, with reduced oil consumption and stable lubrication across temperatures.

Conclusion

If you own a General Motor vehicle, there’s only a few things you need to remember to keep your engine in tip-top shape. In terms of lubrication, at least. First, match the correct Dexos specification to your engine type (gasoline versus diesel, performance versus standard). Then, use the viscosity grade your owner’s manual calls for, and don’t mix specifications. 

A Dexos 1 Gen 3 oil won’t hurt a Gen 2 engine because of backward compatibility, but a Dexos 2 oil in a gasoline engine calling for Dexos 1 absolutely will cause problems. If you’re outside warranty and want to use a non-licensed oil that meets the specs, that’s your call. Be keep your maintenance records detailed and consider shorter change intervals as insurance against any formulation gaps.

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