Tell me about special coolants

I'm about to replace the thermostat in a '95 Jetta with an ABA (that's the 2-liter 4 cylinder, gasoline engine)

It's supposed to use some magic antifreeze -- G12, maybe -- and that comes in pink and blue flavors. (Edit: The magic coolant ball is labeled G11.)

FWIW, it appears to have plain green antifreeze in it now.

This is the most modern car I play with; so I have no experience with these special coolants. So, I'm looking for an excuse not to bother. I mean, it's just coolant, right? It has to be wet, and non-corrosive, and not freeze at the temperatures I'll encounter. Other than that... what's the difference?

Will it hurt anything to re-fill it with what's in it now -- plain old green antifreeze?

It won't hurt to use what's in there now. However, I prefer Toyota Red coolant. I use it in everything water cooled, from the Rolla to the Lotus.

Here's a basic primer on some of the differences between "old" and "new" coolants:

• The old green stuff is ethylene glycol; the new stuff is propylene glycol. The latter is, I believe, more stable and thus can be used safely for longer intervals.

• New-generation coolants generally have higher levels of anti-cavitation compounds; reduced cavitation means better heat transfer.

• New-generation coolants are often silicate- and/or phosphate-free, required by some manufacturers for compatibility with materials used in the cooling system (like composite water pump impellers).

• Many new-gen coolants employ organic acid technology (OAT) or hybrid organic acid technology (HOAT) chemistries that (I hope I'm recalling this correctly) help to create a protective layer between the coolant and the surfaces of the cooling system, improving corrosion resistance.

Personally, I've used G-12 VW coolant and G-05 universal coolant (Zerex) with excellent results. No green snot of death, double the life, easy on water pumps. I'll never go back to the green stuff.

Prestone has a coolant that is supposed to be useable with any other coolant, and its the same price as their regular coolant I think (or within a few $s).

"Prestone® Extended Life Antifreeze/Coolant is compatible with ANY antifreeze/ coolant – regardless of color – for use in ALL makes and models of cars and light duty trucks."

Bob

02Pilot wrote: Here's a basic primer on some of the differences between "old" and "new" coolants: ---snip Personally, I've used G-12 VW coolant and G-05 universal coolant (Zerex) with excellent results. No green snot of death, double the life, easy on water pumps. I'll never go back to the green stuff.

Interesting. I hadn't thought about the possibility of the coolant being corrosive to plastics. Lots of plastic in this cooling system, I know.

About the longevity issue -- weren't some of the "new" coolants (I think I remember hearing about GM having this problem) turning to jelly at relatively low mileage?

Matt

that was GM.

A lot of the special mfg-branded coolants come from the same manufacturers. Toyota Red, for example, is the same as the Subaru green coolant down to the percentage of each additive the shape of the bottle. Of course it's dyed green, but maybe they've changed that recently...

I prefer to use only MFG-recommended coolant during the warranty period and then whatever I want the rest of the time. Usually that means generic silicate-free stuff like the Zerex G-05.

Most of us 9C1/Impala SS owners think the orange DEX-Cool is the devil. Have you seen the orange goo that comes out of a cooling system when you flush it?

IIRC the Deathcool problem was related to faulty intake manifold gaskets that allowed air into the cooling system. That seems to cause the coolant to turn into Jell-o. Dex-cool is an OAT, whereas many of the others are HOATs and do not seem to suffer from this problem.

Since you all seem to know more than I do (thanks 02pilot) ... Are any of the coolants better for the environment/pet safe?

I live in an area full of home wells, Lakes, bears/dogs/kids etc. I try not to spill but you never know.

As far as I know, all the commonly found coolants are fairly toxic. There is some sort of pet-safe coolant out there (marketed as such), but the name escapes me. I also don't know anything about its properties or cost. Sorry.

So ... the Prestone shots my buddies and I did for new year's were a bad thing? Who knew?

A little in-depth reading on the Dex-Cool issue can be found here: http://www.zillamotorsports.com/DEX/

I have a 99 pontiac grand prix, not too long after I got it I flushed the dex cool slime out and put green coolant in it and it has been fine for 60k miles. As far as VWs, from everything I have heard it is not a good idea to run normal coolant in them. If I were you I would buy the correct coolant rather than just using the green stuff.

New coolants are still ethylene glycol. Don't know of any auto maker specifying propylene glycol.

All in all, it's the same stuff, just died different colors. At least that's what the manufacturers and recyclers of the stuff have told me.

I just bought a gallon of Toyota coolant over the break and paid $23 a gallon! WOW.

I tried to buy some radiator flush, but none was on the shelves in two stores. I guess they don't sell it any more. I was amazed at how clean the coolant was that came out.

The label on this stuff had several ingredients listed, but ethylene glycol was No 1. I think it had some propylene glycol in it.

The Sierra brand is the one that is pet safe and is propylene glycol. I have used it before with no issues. You can buy it at the major parts stores

http://www.sierraantifreeze.com/

I have 3 VW's and have always used G12 on them. I have always heard the G12 does not mix well with anything else, so you need to flush very well if converting.

My dogs do not have access to my garage, so I am not really worried about them getting into anything. If there was any chance I would use the Sierra. Cars are just cars, but my dogs are part of the family.

Yes...propylene glycol is the low-tox stuff. Propylene glycol...I'm pretty sure...is used as a food additive also. Even in many "natural" foods.

One way or the other...most of this stuff ends up in the ground. Any time my cars get cooling system work, they get converted to low-tox. When friends ask for help with their cooling systems, I only help under the condition that it get's changed out to low tox. I've never owned any VWs...

Clem