Anti freeze

[M6Scout]

Experience is the best knowledge so that being said Is there a preference on which brand is better for our radiators and engines?

Thanks in advance

[PoW]

Prestone mixed 50/50 with H20 has worked for me over 55 years.

Glycol is glycol. It does job.

PoW

[sturmtyger380]

Since I started from a fresh rebuild on my M38A1 and will soon with my M37 I have been using the orange coolant - Dexcool.

Here is a blurb from a website:

The Dangers Of Mixing Green And Orange Coolant

Vehicle engines require coolants to keep them from overheating. In the past, there was only one kind of coolant (anti-freeze) and that was the green liquid. Today, there are two: The green coolant and the orange colored coolant, which is also known as Dexcool. Let’s look at these more closely.

The green coolant is an inorganic additive technology (IAT). With this type of coolant, phosphates along with silicates are added to ethylene glycol. This helps to protect the metals that are in the vehicle’s cooling systems from becoming corroded. There are some IAT coolants that use propylene glycol instead of ethylene glycol.

The orange coolants are organic acid technologies (OAT). These were created for newer vehicles that had more nylon and aluminum parts in them. OAT coolants use organic acids in order to prevent corrosion.

Some people believe that they can mix the two. This is a mistake and can lead to expensive repairs. The two coolants should never be mixed together as they do not react well. When mixed together they can form a thick, jelly-like substance that can completely stop all coolant flow which can lead to overheating. As the coolant stops flowing, other problems can occur as well such as happens with radiators, water jackets, and even heater cores. The water pump may overheat and stop working. In severe cases, head gaskets can blow, and heads may warp. The engine itself will encounter major damage.

https://kernersvilleautocenter.com/the- ... corrosion.

[vargaspj]

I use the conventional concentrated O'Reilly house-brand green antifreeze part No GAL Line AFZ from O'Reilly auto parts. It's listed on the front for use in 2000 and earlier Ford & Chrysler and 1995 and earlier GM and all other makes & models. It's concentrated which means you need to add water; I dilute it 50% with distilled water when I use it in my 1952 M37.
As discussed in the earlier post, mixing different anti-freezes is not a good idea because nowadays the different auto manufacturers are very specific about which antifreeze type gets used in their vehicles. The different anti-freeze blends are chosen for compatibility with the metal alloys and other parts they use in their engine systems to keep efficiency up and corrosion down.
These old M37 and M37B1 beasts that we have were last produced I believe around 1968, which puts them well before the 1995 cut-off for the O'Reilly antifreeze listed above (back when a truck was a truck was a truck). Like I said I mix it 50/50 with distilled water and it seems to work well for me.
I think any other "green" type of Ethylene-Glycol antifreeze that you get that is listed for use in older cars would also work just as well.
Again, I wouldn't use any of the "newer" anti-freeze types or mix anti-freeze types in these old machines.