Is there any suitable replacement for the OEM VW Audi G12? Yes there is.
G12 replacement or Audi replacement coolant other then G12 is out there. Below is more information on what and why.
First off always try to use the fully recommended coolant G12 can be found at every Audi VW dealer.
If you can’t get to a dealer what choice you do you have? Look into Pentosin coolants. They are recognized as a direct replacement for All Audis. But if not OEM or Pentosin what else.
Here are a couple suggestions that have been found to be in line with what G12 coolant seems to provide. You see lots of coolants saying that they are compatible but are they. What you will see often is them saying they meet or exceed the standards of the G12 coolant. But does that mean they will work and be ok in your car. Lots of people say no. To better understand why come coolants and mixes work and others don’t lets explain what coolant is and why getting the mix wrong can lead to damage.
All coolants have chemicals added to help in pulling heat away from the motor to (cool ie coolant) cool the motor and there are chemicals added to assure the fluid won’t freeze (antifreeze)So this is why we call it coolant or antifreeze. There are also other chemicals added to help in lubrication, corrosion inhibitors and others for buffers. There is also color added to help in recognition of leaks and to help in identification while helping give an idea on proper mixing. You can usually tell if the mix is too strong or too diluted by looking at the color consistency. As the years have moved on and the motors have become more and more complicated with higher requirements things needed to change. The older style of coolant (green stuff) had a shorter life then most people understood. Most of the time people would keep the coolant in way past its normal life. This was not only bad for the motor it was bad for some of the motor components. As the motors became more demanding the gaps between servicing the motor and the oil needed to change as well. People wanted longer distances between needing to service oil and coolant.
The way Audi solved these issues for the bigger requirement was with a different blend of chemicals using a new classification. The big requirements of the coolant come down to the classification of them and how that changes things. In comes Organic Acid Technology or OAT biased coolants for short. Organic Acid Technology = propylene glycol. The OAT name is also seen when referred to as Dex-cool. G12= Organic Acid Technology or OAT for short. Switching over to the new G12 or OAT style coolant has lots of advantages the OAT coolant has very similar corrosion protection as the older green coolant but its slower acting and is more stable resulting in it being slower acting and taking much longer to break down. This helps give it that extended life extended mile protection ability. It is made from a propylene glycol base which makes it less poisonous than the older coolant and being less toxic and poisonous it is much less harmful to the environment. Now if you spill your G12 OAT coolant you don’t have to worry about killing your neighbor’s dog. The OAT coolant is much safer for children and pets.
So the new OAT is longer lasting safer and has some added protection that older coolants didn’t. One of the things that older cars and coolant had issues with was the fact that older coolant wasn’t very helpful in preventing electrochemical degradation. electrochemical degradation or ECD is where the motion of coolant and water through your engine creates an electrical charge similar to a galvanic battery. This electrical charge degrades both rubber and metal parts in the cooling system from the inside out. ECD can be attributed as the cause of many premature coolant system failures. OAT coolants reduce the effects of ECD because the OAT coolants conduct less ECD then the older coolants.
Now that we know all that can’t we just poor any coolant into the car that says it meets all the requirements to be used in any car. There is a difference between performance requirements and chemical requirements. When you see most coolants they will say that they pass the ASTM D-3306 and ASTM D-4340 standards. What does that mean and is that all you need to know.
ASTM D-4340 = Test for new coolant. Aluminum Hot Surface Standard Test Method for Corrosion of Cast Aluminum Alloys in Engine Coolants Under Heat-Rejecting Conditions
ASTM D-3306= Automotive service interval. Standard Specification for Glycol Base Engine Coolant for Automobile and Light-Duty Service.
So these are two tests for performance but all these tests don’t say they meet the chemical requirements. Generally seeing these two tests and the OAT specification would help make for a better combination. We see OAT used more often in the name of DEX-COOL™. DEX-COOL™ came with wide panic after it was found some of the GM cars using DEX-COOL™ had head gasket issues. There was a lawsuit and reports say the over all formula has been changed and that most of the findings showed that the damage was only on cars that had constantly low coolant amounts. Where the cars were beyond the low limit for extended sections of time. Not all cars had issues either just some. Still DEX-COOL™= OAT
My list of what looks like usable coolants come from matching the requirements and looking at the MSDS that was available. Tracking down all the chemical data is hard as MSDS only show information on chemicals that appear to be hazardous. After gathering as much as I could from the MSDS I looked into cross referenced cars that also could use G12 coolants and what other coolants those cars were able to use.
The bigger issue here is in the mixing. If you want to flush out your cars coolant all the way almost any new long life so called universal coolant will work just make sure its formula contains no silicates, phosphates, borates, nitrates or amines. Using the long lasting coolant should have a good formula. We know that the main part of the Organic Acid Technology (OAT) minimizes corrosion inhibitor depletion. So other formulas doing the same should be fine.
So what can you use. The good part of this is that you can always use the G12+ and G13 fluids. The newer G13 fluids can be put in older cars (G12) but the older fluid (G12) can’t be used in the newer cars G13. So if you have access to newer coolant that can always be mixed in. So far from what I have seen these can be used and mixed with little or no issues. They can also be using 100% as a replacement for G12 and I know they can be because I use one of them as a replacement and I know several VW audi shops that have used it for mixing with peoples G12 for years with no issues.
If you find a coolant you know or think will work add it to the thread we can investigate and add it to the list if it works. Right now I have
HAVOLINE® EXTENDED LIFE ANTI-FREEZE/COOLANT DEX-COOL
STP® Extended Life Antifreeze/Coolant
Zerex DEX-COOL™ Antifreeze / Coolant