I'm almost embarrassed to even ask this (since I've been turning wrenches for a living for the last 28 years...!) but can anyone out there explain this coolant puzzle for me? I've asked everyone I know that should know but even the company Service Reps I've spoken to can't tell me.

Here's what I do know...

EG...Ethylene Glycol
This is the stuff we all used since "the beginning of time". Looks blue or green in the bottle, green once mixed in the coolant system. Kills any animal that drinks it.

PG...Propylene Glycol
Newer stuff. Not the poison that the EG is. Can supposedly be mixed with EG without harmful effects, but renders any method of checking the protection level useless. Color? I've personally seen PG coolant in purple, pink, and blue/green (like typical EG)

Dex-Cool
Orange is the only color I've encountered so far. It's an EG-based coolant.

Can anyone add anything to this?

Why are there three colors of PG? When the pink is mixed with the green it looks just like EG coolant and promotes mis-identification.

Just what is the deal with Dex-Cool? What differs it from the "run of the mill" EG based coolant?

I'm ready to receive your vast knowledge!!

 

Did a Google search on Dex Cool and got over 28000 hits. Apparently GM has a nice little lawsuit about this antifreeze. Claimed it would last 100000 miles and according to alot of customers it did't.

 

Most all anti-freeze is EG based, its just the corrosion inhibitors that are different. The Propylene Glycol IS different, and as you said, is less toxic, and probably more importantly, doesn't taste sweet and so does not attract animals and children to drink it. The PG has a different specific gravity, so it doesn't read the same in the freeze protection testers.

The "green stuff" is what we're all familiar with, and basically does a good job if you don't leave it in too long.

The "orange stuff" is the Dex-cool you mentioned. It has a whole different system for corrosion resistance, is not compatible, but was supposed to last longer. It also is more expensive.

The Motorcraft Premium Gold (aka Zerex G-05) "yellow stuff" lasts longer, IS compatible with the green (although you lose some of the longevity), and costs only slightly more. It is supposed to be particularly good for your play things that don't get driven regularly. I think Ford was going to switch to it across the board until they got the cost cutting edict from Bill Ford.

Both Ford and Chrysler DO recommend the Gold, and I think GM will eventually (although they may be gun shy after the problems with Dex-cool), but they don't seem to supply it in new cars. I guess this is because it does cost a little more and very few people would appreciate the advantage.

 

I have a 2000 merc gran marquis in addition to my truck, I did a flush and fill (with the stat out) and used prestone 5-150 extended life that is supposed to be compatable for ford and gm that have the dex cool antifreeze rating. It is supposed to be for aluminum radiator/heater core systems. Did i use the right stuff in my ford product?????.

 

My owners' manual (2001 F150) says, "DO NOT USE Ford Extended Life Engine Coolant (orange in color)". That would be the Dex-Cool stuff. I know it is not compatible with the factory coolant, but this seems to say that you can never use it. However, the fact that such an animal exists, seems to imply that it must have been acceptable for some Ford products.

I would guess that it'll be OK if you've flushed well, and don't try to get 5 years out of it. Maybe somebody else can tell you why Ford recommends against it.

 

The Dex Cool is an OAT based product (Organic Acid Treatment). IT IS NOT NOW, NOR WAS IT EVER compatible with the Ford system. It is corrosive to Ford internals. GM is now finding this out with their vehicles.
The G05 is a modified OAT, that is compatible with Ford systems (extra silicone content). You can mix the green EG with G05 in a pinch, but it is not recommended.