Can You Mix Dexron 2 and 3?

Oil specifications can be confusing, and it’s difficult to find all the information you need on an oil can or bottle label. Questions like these are pretty common, and with so many products out there, it’s understandable that people have doubts. After all, using the wrong hydraulic fluid can cause irreparable damage to your vehicle. From my experience as a repair shop owner, I clearly understand your concern, and I will share my professional experience and knowledge to help you answer this question.

So, can you mix Dexron 2 and 3? You can safely use Dexron 3 in transmissions designed to work with Dexron 2 because Dexron 3 has been designed to be backward compatible with earlier versions. However, using Dexron 2 in newer transmissions (1993 and up) is not recommended because it could damage your transmission.

It’s interesting to learn how as automatic transmission and power steering systems evolve, they require more efficient and stable fluids to ensure proper operation.

Knowing this will help you understand more about the difference between Dexron 2 and 3, and why you should be careful about what products you use on your vehicle.

What Are the Risks of Using Dexron 2 ATF on Transmissions Designed for Dexron 3?

Although it can be tempting to use Dexron 2 to top up your Dexron 3-rated ATF, it’s important to consider that Dexron 3-rated transmissions have many electronic components, and only the Dexron 2(E) was conceived to be used on modern transmissions, and it can still be harmful to your transmission’s electronic components.

Below you will find a list of the potential damage using Dexron 2 ATF can cause to modern vehicles.

  • Slippage and failure due to compatibility issues.
  • Overheating due to poor ATF performance.
  • Poor low-temperature performance.
  • Solenoid and other components damage.
  • Reduced transmission lifespan.
  • Ineffective corrosion protection.
  • Unstable operating temperatures, which can trigger TCM (Transmission Control Module) fault codes.
  • Reduced seals and other components’ lifespan.

Is it safe to use Dexron 3 ATF to top up a transmission that uses Dexron 2?

Yes, transmissions designed to use Dexron 2 ATF work perfectly well with Dexron 3 ATF, and it’s completely safe to top them up with Dexron 3 as they blend perfectly.

Just ensure to avoid overfilling and follow the manufacturer’s instructions to prevent damaging the transmission seals and other components.

If you have a pre-1993 GM and use it for long periods, in a cold weather zone, or sporty driving, it’s a good idea to upgrade to Dexron 3.

More information about Dexron 2 and 3

Dexron is just a commercial name General Motors assigned to the ATF compatible with their vehicles’ transmissions. Let’s see something more about these ATFs’ properties and history.

Dexron 2

Dexron 2

In 1973 General Motors developed Dexron 2 ATF for using it on their vehicles’ automatic transmissions. It was a long-lasting, high-quality product that met their transmissions’ requirements, ensuring smooth operation, proper lubrication, and cooling.

The early versions of the product caused some problems with transmission seals and weren’t very effective against corrosion. GM continued improving the product over time, increasing its performance and durability. The oil’s specifications were so effective that other automakers and transmission manufacturers adopted it for their own products.

As electronics were introduced and transmission became electro-mechanical, manufacturers needed more stable and reliable automatic transmission fluids.

The new technology demanded a new kind of transmission fluid capable of ensuring proper functioning under all weather and temperatures.

Besides, the fluid should be unharmful to the transmissions’ solenoids and electronic components exposed to it. This resulted in the introduction of the Dexron 2(E) in 1990.

Dexron 3

Dexron 3

In 1993 GM launched Dexron 3 ATF. It was a highly improved version of the Dexron 2(E), which promised better friction, high temperature, and oxidation protection, among other qualities. However, there was still much room for improvement, especially regarding long-term durability and rust prevention.

The product was improved until its last version, the Dexron 3(H), was released in 2003, solving most of the previous versions’ issues. This is the latest iteration of the Dexron 3 ATF.

Amazingly, all Dexron versions work exceptionally well on GM vehicles built from 1949 to 1966.

Alternatives to GM’s Dexron 2 and 3 Products

There are several alternatives available for GM’s Dexron 2 and 3 transmission fluids. Some well-known brands, such as Castrol, Mobil 1, Motul, and Valvoline, among others, offer multi-brand ATF fluids that meet and sometimes exceed GM’s performance standards.

GM’s Dexron 2 and 3 never were full synthetic oils, but these days you can find fully synthetic versions of this ATF, mostly the Dexron 3, which enhance gearboxes’ operation, improve shifting quality, and offer a great deal of tear and wear protection, ideal for high-performance use.

Which Automakers Recommend Using Dexron ATF?

Of course, GM brands (Buick, Cadillac, Chevrolet, GMC, Holden, Opel, Pontiac, and Vauxhall) use Dexron ATF, but other brands like Honda, Ford, Nissan, and Toyota use it as well. Ford’s Mercon ATF has very similar specs to the Dexron 3. However, it’s important to always check your vehicle’s user manual before choosing an ATF.

Can I use Dexron 2 or 3 as Power Steering Fluid?

Most power steerings use ATF as power steering fluid, and Dexron 2 or 3 is compatible with many vehicles. Sometimes you will find “Dexron” written on your power steering’s filler cap, and you can also see what ATF you can use on your vehicle’s user manual.

Dexron III works particularly great as a high-quality power steering fluid, providing consistent and reliable performance under the most extreme operating conditions. Besides, it has excellent wear protection properties, helping to maintain the longevity of the power steering components and preventing oxidation, deposits, and sludge formation.

Related articles:

Dexron III vs vI Transmission Fluids: Which One To Chose?

Is power steering fluid the same as transmission fluid?

does changing transmission fluid improve performance?

Who Worked on This?



I'm the guy responsible for ensuring that every blog post we publish is helpful for our reader.

Mahir Ahmed


I'm the guy responsible for ensuring honest, informative, accurate and helpful guide to the reader.

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