Coolant Chaos - Which Coolant do I use.. HOAT, OAT, Type A, Red or Green ?

[old dave]

Being a long time responsible owner of series 1 Pajero's A SWB NF Turbo Diesel and a NG LWB V6 I take a lot of interest in keeping these vehicles trouble free and reliable by keeping the best coolant in these motors.
The SWB I have had for about 16 years and the LWB about 5 years.. so they are both long term or forever vehicle for me..
I heard a lot of good things a while back on new advanced coolants of the OAT or HOAT technology and flushed the green coolants previously used and moved to PENRITE Red 8 year coolant.. PENRITE classify this coolant as a TYPE A OAT coolant. On the back of the container they state that it protects all internal surfaces from corrosion, including aluminium.
Now I have very recently read on the back of a NULON red coolant container that this type of coolant attacks Brass/Copper radiators and lead solder ! shouldn't be in my vehicles if this is the case.

The PENRITE web page for coolants doesn't contain any specific warning against using the red coolant in older vehicles... using the search tool for coolants on their site, it says the RED is fine for the 1988 Turbo Diesel but for the 1989 V6 it points me to to their green coolant. Both have brass radiators and I presume soldered joints as well.Not sure why they would reccommend different coolants.
There is no clarity at all.. Any advice welcome...
Dave

[old dave]

More Info..

I found this on a classic car site re the use of modern red OAT type coolants in older cars (with brass radiators)
Hi,

Information was just published in the Auburn Cord Duesenberg Club Newsletter concerning the use of "extended life" antifreeze in cars over 10 years old.

In a nutshell--don't do it!

Under NO CIRCUMSTANCES should an "Extended Life" antifreeze, which utilizes Organic Additive Technology (OAT, H-OAT, or N-OAT) as one of its chemicals, ever be used in our cars over 10 years old. It attacks the gaskets and gasket cements in our cars, causing major leaks and forcing ultra-expensive repairs. The "Silver Ghost Association" Rolls Royce people have documented massive cooling system failures apparently caused by this anti-freeze product.

Antifreeze that can be used safely in our cars uses older-fashioned Inorganic Additive Technology (IAT) additive.

You cannot tell by the color of the antifreeze if it's safe to use. Also, the product may be labelled "Safe for Older Cars"--meaning 10 years old at most

Also I contacted PENRITE... while saying nothing negative about the suitability of the RED long life coolant they just said both my vehicles were suitable for their 7 year GREEN coolant... and they would supply me with it free... I think I have drawn my own conclusion..

[Dicko1]

Gone are the days of just whacking a bit of coolant into the radiator! So long as it said coolant on the bottle the old Holdens and Fords didn't mind at all..

[TomW]

I had a quick google as well and while I found a lot of conflicting information most of it did tend to suggest that using the green coolant was best to ensure continued protection of the cooling system. I use the green in my NG and have never had any issues with overheating or anything.