Thread: OAT and HAT

Originally Posted by dearot

Mine develops leaks after changing all coolant hose last year. And the mechanic that ask to check the leak recommend using toyota red coolant (I read on the internet they are HAT). They also say it is safe to use HAT when OAT or normal green coolant has been used.

I know it has been discussed alot in the forum and I have read them all but most of them are 2-3 years old thread.

So I thought I post this thread to see how many of you use HAT and see what the good thing and bad thing about using HAT.


Thanks
Gus

OAT coolant was designed for use in engines with aluminium heads, blocks etc to elimanate corrosion and provide better wetting, thus better heat transfer & cooling. HAT coolant(Hybrid Acid Technology) is an advance on OAT.

Hybrid Coolant

Inhibitors based on a combination of inorganic salts (as found in traditional coolant) and some fully neutralized organic acids (as found in OAT coolant)
Typically yellow or red in color
Designed for use in both automotive, light duty and heavy duty diesel applications
Formulations are available: with or without nitrite/ with or without borate / with or without phosphate/ with or without silicate
Product can have good coolant to coolant compatibility
Excellent wet sleeve liner cavitation protection
Good high temperature aluminum performance
Generally compatible with SCA’S and Coolant Extenders
Extended life in both light and heavy duty applications; mixed fleet application
Lifespan: Automotive - Up to 5 years or 250,000 km (150,000 miles); Heavy Duty - Up to 6 years or 960,000 km (600,000 miles)
As the name suggests, this coolant technology takes the “best of both worlds” approach and combines the benefits offered by traditional corrosion inhibitor technology and marries this with the benefits of OAT corrosion inhibitor technology. This hybrid technology is also referred to as HOAT technology. Its presence is definitely growing in the North American engine coolant market at both OEM factory fill and the general engine coolant aftermarket.

This technology can have excellent coolant to coolant compatibility making it suitable for top-up use with Traditional or full OAT coolants.

so does that mean I can use it as a top up to my traditional (glycol) coolant and not need to be quite so pedantic about flushing the system when I refill?
I know I shouldn't be using glycol but that's what was in the engine when I got it 35k km ago so i just kept going...
Alex

Originally Posted by Alex 110

so does that mean I can use it as a top up to my traditional (glycol) coolant and not need to be quite so pedantic about flushing the system when I refill?
I know I shouldn't be using glycol but that's what was in the engine when I got it 35k km ago so i just kept going...
Alex

How do you know that yours is traditional (glycol) coolant? Is it because green colour? Nulon hybrid coolant is also green.

Originally Posted by dearot

How do you know that yours is traditional (glycol) coolant? Is it because green colour? Nulon hybrid coolant is also green.

I drained the old coolant & refilled with glycol when I bought the D2 & no sludging up or anything that would happen if I'd mixed coolants

I have worked at a Toyota dealership for a few years now (and still prefer my d2 TD5 compared to the issues I do see with Toyotas), I use the Toyota RED coolant as opposed to the PINK. They are the same ingredient just the pink is 5L ready to use as is, IE don't add water. The RED is a 4 litre bottle that you then add water and will make up 10litres. At $40 retail for 4l it is very cost effective and as stated above is as compatible as OAT if not better.


But...................I still get water leaks from the fuel cooler, especially in the colder weather.

Is toyota red coolant oat or hoat?

Forget Oat, Hat, Jumper, and any other fancy names for coolant. Just use Cummins PG Platinum. Reasonably priced, never have to change it again, can be mixed with other stuff(best not to though) and is environmentally friendly.

It is a no brainer IMO.

[ame=http://www.youtube.com/watch?v=_d8x2piUzB4]Are all coolants created equal? - YouTube[/ame]

Originally Posted by dearot

Is toyota red coolant oat or hoat?

according to Toyota tech dept, it is HOAT but were a little cagey about the exact ingredients. I work here so I do get it cheap and it is quite ok to use in a td5.