What is this stuff?

[Steubie]

There is so much I don't understand about coolant! Seems like things got pretty weird after about 1993!

So I have a 2021 Kia Rio which needed a little top off of coolant. I spent WAY too much time trying to figure out if it's an OAT, HOAT, PHOAT, or maybe even a POAT (if such a thing even exists). Then I started seeing a bunch of stuff starting with "G" (G05, G12, G12++, ect.) and my head began to ache.

So I went way out of my way to go to a Kia dealer, and even they weren't sure what might be in it, but appeared much more confident when I told them it was pink. They sold me the stuff you see in the pictures.

So, good people, I hope you can help me with two questions:
1) what kind of coolant is that, and
2) where can I find out about what exactly makes each type of coolant different, and how to correlate the chemical composition of the coolant to its name, such as G05 or PHOAT?

 

[Urshurak776]

Just curious, why would a 2021 need a top off of coolant? Leak?

Our 2014 Rio never needed a drop.

 

[Steubie]

Just curious, why would a 2021 need a top off of coolant? Leak?

Our 2014 Rio never needed a drop.

I'm guessing that maybe there was some air in the system after the factory fill. It was a bit below the full line on the overflow reservoir when I bought it, and dropped a bit after 5k miles. I added a about 8 fl ounces last September. Level hasn't fallen again yet, and I'm at 33,000 miles now.

 

[Hyundai Respecter]

It’s confusing to me too. I’m pretty sure my 2019 Soul has green coolant, before Kia went pink, and I’m positive the older 2011 Soul is green.

Not sure exactly what the difference is with green and pink coolant other than the color. They both use phosphates and are silicate free. This article might help you. It made it a little less confusing for me…

Gears Magazine - Cool It: What You Need to Know about Your Vehicle's Cooling System

A recent study found that up to 40% of all engine failures were a direct result of cooling system issues. As the vehicles we service continue to evolve, the coolants and systems designed to keep our transmissions and engines operating at the correct temperature are also changing. Many of the...

gearsmagazine.com

 

[Steubie]

It’s confusing to me too. I’m pretty sure my 2019 Soul has green coolant, before Kia went pink, and I’m positive the older 2011 Soul is green.

Not sure exactly what the difference is with green and pink coolant other than the color. They both use phosphates and are silicate free. This article might help you. It made it a little less confusing for me…

Gears Magazine - Cool It: What You Need to Know about Your Vehicle's Cooling System

A recent study found that up to 40% of all engine failures were a direct result of cooling system issues. As the vehicles we service continue to evolve, the coolants and systems designed to keep our transmissions and engines operating at the correct temperature are also changing. Many of the...

gearsmagazine.com

Thanks, good article, I read it while researching, but it leaves me with so many questions, like:

1) What is the connection between HOAT and the label G-05?
2) What about the different uses of silicone in the HOATs?
3) Why doesn't the "Asian Red" clearly state what it is, in terms of whether it is a P-HOAT or G-12 or whatever?
4) Is there a difference between the OAT and Dexcool?
5) Why are some coolants using phosphates, some silicates, and some seem to use neither?
6) How am I supposed to know which ones closely mimic the original fill, and what are the consequences of mixing different coolants?

Thanks!

 

[brianl703]

This coolant has 2EHA. Not many coolants contain 2EHA. 2EHA is used in Dexcool and "all makes, all models" coolants.

 

[Steubie]

Does anyone know if this is HOAT?

 

[BrandonV]

The pink Kia coolant should be P-HOAT. Try not to get too hung up on the color. It's a good guideline but is mostly irrelevant. Toyota, Nissan, Honda, Hyundai/Kia all use P-HOAT and you'll find it in blue/green & pink mostly.

 

[Steubie]

The pink Kia coolant should be P-HOAT. Try not to get too hung up on the color. It's a good guideline but is mostly irrelevant. Toyota, Nissan, Honda, Hyundai/Kia all use P-HOAT and you'll find it in blue/green & pink mostly.

I appreciate the advice about not getting hung up on color, but things would be so much easier if colors were standardized, or if the containers would let you know the composition of the coolant.

I see that you suggest it is P-HOAT, which makes sense, since that seems to be the composition of Zerex Asian (see link). However, other people who seem to know what they are talking about suggest that it is P-OAT, which also makes sense since that seems to be the composition of Peak Asian (see other link).

Clearly I don't want to mix the two different compositions. So how can I tell what is really in there?

 

[kschachn]

You noted that you already bought some OEM coolant, so what’s the issue here? I’m a little confused. Just use what you have.

 

[Steubie]

You noted that you already bought some OEM coolant, so what’s the issue here? i’m a little confused. Just use what you have.

Sorry to confuse you.

First, it seems natural to me to want to know what kind of coolant is in there so that over the lifetime of the vehicle I know what I am doing, beyond this little top-off.

Second, the coolant from the dealer contains 2-eha, which some on this forum are averse to using. If I were to want to switch coolants to something without 2-eha, I want to make sure the second fluid is not going to react strangely with any original left in the system.

Third, I have run into coolant compatibility issues with my other vehicles, and would like to know in a general way how to tell which coolant is which for all applications I am likely to encounter.

At this point, with some manufacturers switching between coolant types so often, I don't even feel like I could really trust the person behind the parts counter at the dealer or my local supply store to know what the OE is, or the appropriate aftermarket solution.

Maybe no one knows how to tell which coolant is which, and we all are helplessly at the mercy of a non-standardized mess.

That is what I am asking here, and the point of this post.

 

[BrandonV]

I appreciate the advice about not getting hung up on color, but things would be so much easier if colors were standardized, or if the containers would let you know the composition of the coolant.

I see that you suggest it is P-HOAT, which makes sense, since that seems to be the composition of Zerex Asian (see link). However, other people who seem to know what they are talking about suggest that it is P-OAT, which also makes sense since that seems to be the composition of Peak Asian (see other link).

Clearly I don't want to mix the two different compositions. So how can I tell what is really in there?

Terms get thrown around a lot w/ coolant.

IAT = mineral inhibitors only
OAT = organic additives only
HOAT = mineral inhibitors & organic additives

HOAT in Europe is frequently OAT w/ silicates & no phosphates. HOAT in Japan is frequently OAT w/ phosphates & no silicates/etc.

P-HOAT & P-OAT for the most part are the same thing. You can't have a P-OAT coolant without having mineral inhibitors (e.g. phosphates). The very nature of P-OAT makes it a HOAT coolant. You could mix any of the Asian coolants together without any issue.

Seriously... if you ever look at most Asian cars they will say to use the factory coolant only (no recommendations/etc.). As long as you're using the Kia coolant don't sweat it. If you ever decide to switch I'd just make sure the system is flushed out of the old stuff. I've seen Asian vehicles run on the "wrong" coolant for years to no ill effect. As long as the whole system is running just one coolant you'll be fine.

 

[Urshurak776]

Sorry to confuse you.

First, it seems natural to me to want to know what kind of coolant is in there so that over the lifetime of the vehicle I know what I am doing, beyond this little top-off.

Second, the coolant from the dealer contains 2-eha, which some on this forum are averse to using. If I were to want to switch coolants to something without 2-eha, I want to make sure the second fluid is not going to react strangely with any original left in the system.

Third, I have run into coolant compatibility issues with my other vehicles, and would like to know in a general way how to tell which coolant is which for all applications I am likely to encounter.

At this point, with some manufacturers switching between coolant types so often, I don't even feel like I could really trust the person behind the parts counter at the dealer or my local supply store to know what the OE is, or the appropriate aftermarket solution.

Maybe no one knows how to tell which coolant is which, and we all are helplessly at the mercy of a non-standardized mess.

That is what I am asking here, and the point of this post.

So, the KIA dealership / OEM coolant has 2-eha in it. Clearly that's not an issue then. 2-eha has never been an issue, to my knowledge, in any Hyundai / KIA vehicles.

My 2012 Santa Fe got a good distilled water flush and got refilled with O'Reilly universal. I'm sure it had 2-eha in it. About 40K later, had to change starter (2 coolant hoses run right in front of starter bolts, so I just bought new ones) and wound up draining it all again. Coolant was nice and clean. Went with the O'Reilly's universal again. Car ran great up to 168K, when it got totaled.

It's super easy to get coolant these days without 2-eha. But doesn't matter in your vehicle.

 

[Steubie]

P-HOAT and P-OAT are the same thing? Good to know, that simplifies things a lot, thanks!

Terms get thrown around a lot w/ coolant.

IAT = mineral inhibitors only
OAT = organic additives only
HOAT = mineral inhibitors & organic additives

HOAT in Europe is frequently OAT w/ silicates & no phosphates. HOAT in Japan is frequently OAT w/ phosphates & no silicates/etc.

P-HOAT & P-OAT for the most part are the same thing. You can't have a P-OAT coolant without having mineral inhibitors (e.g. phosphates). The very nature of P-OAT makes it a HOAT coolant. You could mix any of the Asian coolants together without any issue.

Seriously... if you ever look at most Asian cars they will say to use the factory coolant only (no recommendations/etc.). As long as you're using the Kia coolant don't sweat it. If you ever decide to switch I'd just make sure the system is flushed out of the old stuff. I've seen Asian vehicles run on the "wrong" coolant for years to no ill effect. As long as the whole system is running just one coolant you'll be fine

 

[Steubie]

So, the KIA dealership / OEM coolant has 2-eha in it. Clearly that's not an issue then. 2-eha has never been an issue, to my knowledge, in any Hyundai / KIA vehicles.

My 2012 Santa Fe got a good distilled water flush and got refilled with O'Reilly universal. I'm sure it had 2-eha in it. About 40K later, had to change starter (2 coolant hoses run right in front of starter bolts, so I just bought new ones) and wound up draining it all again. Coolant was nice and clean. Went with the O'Reilly's universal again. Car ran great up to 168K, when it got totaled.

It's super easy to get coolant these days without 2-eha. But doesn't matter in your vehicle.

I suspect that 2-eha isn't as bad as some would make it seem. It certainly has gotten a lot of bad press in this forum and elsewhere, though.

 

[Urshurak776]

I suspect that 2-eha isn't as bad as some would make it seem. It certainly has gotten a lot of bad press in this forum and elsewhere, though.

Exactly.

There were some vehicles that had materials in them that were not compatible with 2-eha. I think that is probably in the past though.

All universals have 2-eha in them (I believe.) If it was so bad, why would they have it in there? Clearly vehicle cooling systems aren't failing left and right using them.


I think it's wildly overblown.

Also, don't use FRAM. Cardboard end caps! You're DOOMED!

 

[kschachn]

It’s kind of amazing when people admit they don’t know anything about a subject yet they’re adamant about drawing conclusions on that unknown

 

[Steubie]

Also, don't use FRAM. Cardboard end caps! You're DOOMED!

Perfect! Thanks!

 

[Jake_J]

Thanks, good article, I read it while researching, but it leaves me with so many questions, like:

1) What is the connection between HOAT and the label G-05?
2) What about the different uses of silicone in the HOATs?
3) Why doesn't the "Asian Red" clearly state what it is, in terms of whether it is a P-HOAT or G-12 or whatever?
4) Is there a difference between the OAT and Dexcool?
5) Why are some coolants using phosphates, some silicates, and some seem to use neither?
6) How am I supposed to know which ones closely mimic the original fill, and what are the consequences of mixing different coolants?

Thanks!

1. G-05 is the tradename for HOAT from the 1980's that was developed by BASF or Glysantin. The original HOAT was used by Mercedes, Ford, Chrysler, and several mores European makes in the 80's up to the 00's as a factory coolant but is now replaced.
2. Silicates not silicone is are generally found in HOAT's to help with corrosion protection in the short term.
3. Asian Red is a P-OAT or P-HOAT, just a OAT coolant with some phospate added that is dyed red. All the Asian makes are now using P-OAT's that are essentailly all the same with the biggest difference the colour of dye they add to their product (Toyota = red, Honda = blue, etc).
4. Dexcool is GM's tradename for it's OAT coolant. For an OAT to be Dexcool it needs to pass GM's performance test and pay GM to use the name. So Dexcool is just GM's OAT, and there are many OAT's out there.
5. Modern OAT based coolants are adding phosphates and/or silicates to generally help with corosion protection in the short term. It's now became more popluar to add phopshate to OAT or Si-OAT coolants because it solves issues with CAB brazed heater cores used in some vehicles made very recently. Ford has switched from a OAT to P-OAT recently, and BMW and Volvo switched from Si-OAT to PSi-OAT's because of this reason.
6. There's always Google, but just remember that now everbody is using OAT based coolants so you really can't mess it up, at worst the colour could change (but the universal OAT's use a very light dye that solves that potential problem).

One last thing is don't worry about 2-EHA, many modern factory and aftermarket coolants use it and it's perfectly fine. GM used some garbage gaskets back in the 90's that failed early regardless which coolant was used and some people (wrongly) concluded it was the work of 2-EHA and hence the misinformation has been spreading since then.

 

[2EHA]

I suspect that 2-eha isn't as bad as some would make it seem. It certainly has gotten a lot of bad press in this forum and elsewhere, though.

it’s almost like it works in all makes and models or something