Hey guys, I have a 2013 JKU Sport. According to my late night research last night, it seems JKs 2012 and older had Mopar HOAT (Hybrid Organic Additive Technology) coolant which is orange in color and about $25/gallon. But in 2013, they switched to a much more expensive Mopar OAT coolant which costs about $50/gallon. According to my reading, HOAT is orange, and OAT is purple. To add to the confusion, what I read says that if you mix HOAT and OAT, they will gel and can ruin the engine.

The JEEP we bought from a dealership up in Indiana had just received a new short block core, so I assume they drained out all the coolant during the engine change. Looking in the overflow bottle AND inside the radiator, it's clear what's in there is ORANGE in color, and not purple. I'm guessing the stealership in an eternal attempt to save money, went with the cheaper HOAT coolant when they installed the new short block. Maybe they didn't even know better. I don't see any issues with overheating or gelling in the coolant, but I need to know if it is safe to continue using HOAT in the 2013 Pentastar engine. I'm sure there's a reason they made the switch. Is it safe to run HOAT in an engine meant for OAT?

Today and tomorrow are my last days to get any work done on this Jeep before I leave the country bound eventually back to Papua New Guinea, and the Jeep heads to storage until next summer when it ships out.

Should I drain the HOAT out and replace it with the more expensive OAT. Please only those who even know what I'm talking about... I don't have the time for a mistake based on someone's misinformation.

Thanks guys, and may the Holy Force be with you all,

Tom (heading back to Papua New Guinea)

 

I went through this not too long ago myself on my '13. The OAT, although has a purplish tint, looks orange too. If the light hits it properly, you can see the purple additive, but that is what it is....additive, so depending on how you look at it it can appear purple or orange. I would say that the price difference you saw is not real. I recently bought OAT at my local dealership for $23/gallon for concentrate.....which is pretty inline with what they charged for HOAT. I do NOT think they would have used HOAT just to save a buck rather than using OAT. That said......I wouldn't trust the dealer to use the right thing just because they are stupid and there is no way to tell the thought process. You would think that installing block for '13 they would indeed use OAT though. If you really want to boggle your mind, I think you can find some places that even said the OAT that the factory used in '13 was orange, if I recall correctly.

I'd also say that there is no problem running HOAT in a '13+, nor running OAT in a pre '12.....as long as you get everything flushed completely. You could flush the entire system and essentially run whatever you'd like. The big thing is just not mixing. The HOAT was 5yr/100k miles whereas the OAT is 10yr/150k miles. I am not 100% positive, but believe they just changed for the extended period, and in the process have created a huge conundrum for us DIY JK owners on the cusp of the transition.

I think I'd suck some coolant out with a turkey baster or syringe and put it in a clear container. Just looking in the rad or the overflow is not a good assessment to determine color. I know opening my rad, the purple OAT that I KNOW is in there, looks orange. I think that is where I'd start. If it STILL looks orange after that, I think I'd have a discussion with the dealer who did the work and really pin them down on your concerns.

By the way.....how did all your regear work turn out?

 

I like to boil things down to the simplest common denominator. So when you think about it, water can be used in your cooling system to cool the engine, where every coolant out there gets mixed with water. The problem with straight water is that it freezes when the temps drop below 0degC/32deg F, and water expands when it's frozen. So you obviously don't want frozen and expanding ice in your engine cooling system, and those are the reasons for engine coolant. It mixes with water and lowers the freezing point of the liquid cooling your engine. It may even raise the boiling point since the liquid turning into steam would be a problem as well.

Additionally, these newer technology coolants are meant to prevent rusting of the cooling system it runs through, as well as prevent contaminant build ups such as calcium.

So any coolant that lowers the freezing point of water will work, and then additionally rust and contaminant build up isn't something to worry about as an immediate problem but is more a preventative measure down the road improvement. Both HOAT and OAT cover those things. Just don't mix them together because then they turn into a gel. Ice, steam, and gel are bad for cooling an engine.