Asian Blue Coolant

[SC Maintenance]

This doesn’t agree at all with Prestone's take. They have their all-makes product and also a specific color product for each vehicle grouping, all of which contain 2EHA. I’m staying with Prestone and watch with amusement on all the repeated discussions on OAT, POAT, PHOAT, MOAT, ZOAT and what have you. But each to his own. I also don’t care what Europe does. Do not drink 2EHA. Flame suit on.

I don't really care what you use in your own car. But to use an example of success that has no correlation to an Asian vehicle is not a useful analog.

Prestone uses an OAT because it will mix with anything. Thats its benefit - one product on the shelf, a unknowledgeable customer won't hurt themselves. OAT is an extended life concept that came out when most engines were mostly made from Iron.

A HOAT or PHOAT is generally considered a better option for protecting aluminum, which is why everyone has gone to it. Doesn't mean you must use it, but if you want OE level of corrosion protection and life and that is what your car came with, then your stepping down going to an OAT.

I don't have a problem with OAT or 2EHA in the right vehicle but I wouldn't pour it in anything Asian. I would never believe its suggested service life however, especially in an iron block.

European formulas is a whole other can of worms - the history of their coolant has more to do with their tap water being hard than much else. I wouldn't even bring that into this discussion.

 

[Sayjac]

Asian PHOAT, the P in it makes it a Hybrid OAT.
I agree, and that's what I posted earlier. Yet, the PEAK rep who called me insisted theirs was not a hybrid, and was not a PHOAT. ...

In this case "the Rep" is incorrect-wrong and doesn't understand Asian PHoat (hybrid) AF. That simple. Peak OAT Asian is a PHoat/Poat. I'd use it with confidence same as Zerex Asian, Napa Asian and mixed with Asian OEM AF and other Asian PHoat/Poat. If you choose to believe the rep, then don't mix (or use) with other Asian AF, your call and pointless to take it any further here.

 

[mojoe]

In this case "the Rep" is incorrect-wrong and doesn't understand Asian PHoat (hybrid) AF. That simple. Peak OAT Asian is a PHoat/Poat. I'd use it with confidence same as Zerex Asian, Napa Asian and mixed with Asian OEM AF and other Asian PHoat/Poat. If you choose to believe the rep, then don't mix (or use) with other Asian AF, your call and pointless to take it any further here.

In this case "the Rep" is incorrect-wrong and doesn't understand Asian PHoat (hybrid) AF.
That was my conclusion as well - the rep is wrong and misleading. Problem is It's not just the PEAK agent, but the PEAK website that promotes that misconception, and neither "hybrid" or "H" are mentioned in the description. It's obviously a corporate marketing decision (I don't understand why) and the agent was just toeing the line. What's worse, it's not just PEAK, as Zerex calls theirs a "HOAT", not POAT or PHOAT (no "P"), even though their description on the Asian Blue product page clearly says it contains phosphate. Then on another page where they are explaining the different types, they say "a HOAT coolant is a mix of an OAT or organic acids with a silicate, which is an IAT inhibitor making them great protectors of the aluminum engine and cooling system components." That's not true either, because according tothem, their Asian Blue is HOAT, but is silicate free. Then, they list another, separate category calles Si-OAT, which is a HOAT with silicate, even though they just said HOATs by definition have silicate.

Both PEAK and Zerex are playing loose with the terminology. If you Google OAT/HOAT/POAT/PHOAT you will see those same inconsistencies reflected across the board. The final response from Zerex, after I challenged their original response, is that "Because different manufacturers might prioritize different aspects of protection or cater to specific vehicle requirements, the naming conventions can reflect these varied approaches.", which tells me that you can't go by the OAT/HOAT/POAT/PHOAT descriptions used by the manufacturers. Personally, I have no need to mix any coolants anyway; I was just pointing out the bad information while trying to help a fellow board member.

 

[rondhol]

They are all called HOAT, because of the Phosphated in OAT. There are 2 kinds of P-OAT, the one with sebacic acid in Toyota SLLC pink 150k miles rating, and the blue one in Subaru Honda Suzuki that I have no idea what they use but last 250k miles rating.
Aisin who makes waterpump for Toyota sells Ultra LLC colored blue in europe and compatible to all Asian cars 250k miles rating.
My speculation, toyota use biodegradable Sebacic acid and make it lasts shorter than the blue coolant in GT86 subaru.

 

[mojoe]

They are all called HOAT, because of the Phosphated in OAT.

It depends on who you ask.

 

[SC Maintenance]

They are all called HOAT, because of the Phosphated in OAT. There are 2 kinds of P-OAT, the one with sebacic acid

I don't think that is right. There is a HOAT and a PHOAT which includes phosphate.

Sebacic acid is not a phosphate. So unless it has something else it should not be referred to as a PHOAT.

Not saying you can't use it, but Phosphate is another type of corrosion inhibitor. Again, your back to comparing the OEM formula with whatever your pouring in, and trying to decide if it matters. Nissan's coolant I believe are phosphated - which is why I stick with them. I don't know that I have to, but I don't know I don't either.

 

[mojoe]

I don't think that is right. There is a HOAT and a PHOAT which includes phosphate.

It depends on who you ask.

 

[nthach]

It depends on who you ask.

HOAT can refer to the Asian pHOATs or Euro SiHOATs(G-05, G-40, G-48, HT-12). Mopar also uses a SiHOAT. The Prestone Cor-Guard formula as well as Ford’s current yellow coolant is also a pHOAT, so is the previous Peak 10X and current Ecoguard/Titanium/Final Charge Pro-Series/OET formulas. The main difference is the OAT components. Toyota uses sebacic acid in theirs. I believe Honda, Nissan and Subaru use benzoate in their factory fill, Subaru’s aftermarket coolant uses 2-EHA. Prestone and most of the Euros(for now) also use 2-EHA, G-05 is benzoate.

 

[rondhol]

Sebacic acid and 2-EHA are the platisizer and hard to find from the MSDS alone. Only the main part ethylene glycol is listed.

I was thinking to use Aisin P-OAT in my Toyota, and I believe it must be compatible with Aisin water pump and parts in Toyota. It has 250k miles rating and probably not using Sebacic acid for the plastisizer.

 

[mojoe]

It depends on who you ask.

I don't think that is right. There is a HOAT and a PHOAT which includes phosphate.

Sebacic acid is not a phosphate. So unless it has something else it should not be referred to as a PHOAT.

Not saying you can't use it, but Phosphate is another type of corrosion inhibitor. Again, your back to comparing the OEM formula with whatever your pouring in, and trying to decide if it matters. Nissan's coolant I believe are phosphated - which is why I stick with them. I don't know that I have to, but I don't know I don't either.

HOAT can refer to the Asian pHOATs or Euro SiHOATs(G-05, G-40, G-48, HT-12). Mopar also uses a SiHOAT. The Prestone Cor-Guard formula as well as Ford’s current yellow coolant is also a pHOAT, so is the previous Peak 10X and current Ecoguard/Titanium/Final Charge Pro-Series/OET formulas. The main difference is the OAT components. Toyota uses sebacic acid in theirs. I believe Honda, Nissan and Subaru use benzoate in their factory fill, Subaru’s aftermarket coolant uses 2-EHA. Prestone and most of the Euros(for now) also use 2-EHA, G-05 is benzoate.

Again, it depends on who you ask. For instance

From the Zerex website: HOAT(Hybrid OAT) uses Silicates and Organic acids. Then they have a separate category of HOAT, with the defining characteristic being that it contains Silicates and Organic acids, and they call it Si-HOAT. Based on their description, both HOAT and Si-HOAT contain silicates and organic acids. Then they list a separate category of HOAT which is phosphate free, even though the previous category is phosphate free as well. Then there is another category for phosphated HOAT called P-HOAT, which isn't really a HOAT by their definition, since HOATs, according to them, contain silicates.

PEAK insists their phosphated OAT is NOT a hybrid, and calls it a POAT, not a PHOAT. They say that HOATs contain silicates, and that's why their phosphated OAT/Asian Blue is not a hybrid/HOAT

Then all of that was negated by the email I got from Zerex, basically saying that "naming conventions" used by different manufacturers reflect their varied approached to "prioritizing different aspects of protection or catering to specific vehicle requirements".

The conclusion is that when any manufacturer uses these monikers (OAT/HOAT/POAT/PHOAT) they may not mean what we think they mean, or what we think the should mean, and trying to use them to make decisions about which ones to use, or if they can be mixed, without doing a little more research could cause problems. There is no industry-wide, accepted standard or criteria for what OAT/HOAT/POAT/PHOAT mean. That's all I'm getting at.

 

[rondhol]

Silicate is indeed not an organic compounds, but phosphate is organic. So, saying P-OAT is more precise IMO.

Back to my main question, is it Ok to use Blue Subaru coolant in Toyota engine? Is there any incompatibility with SLLC pink coolant besides the color dye alone?

 

[mojoe]

Silicate is indeed not an organic compounds, but phosphate is organic. So, saying P-OAT is more precise IMO.

Not according to Amsoil; phosphates are inorganic:

"Inorganic salts, such as nitrites, phosphates and silicates, ....." and

"Hybrid-organic-acid technology, often called HOATs, is a combination of inorganic salts and organic acids."

It's the inorganic phosphate combined with the organic acids that make it a hybrid and give it the "H" in HOAT.

 

[rondhol]

That's true.. I mixed it up with Organophosphate like in our DNA, ATP, RNA, and phospholipids in our cell membrane.

Yes, strickly speaking PO4 ions and silicate are inorganic molecules.
P-OAT = HOAT
Si-OAT= HOAT

 

[rszappa1]

5 pages on this...thats why I use OEM Honda coolant...no guess work no problem....