what is best coolant? g-05? Mercedes? Porsche?
 

I need to tackle either a bad cap or cracked expansion tank today and would like to change the coolant. Did a search here and found some good stuff (especially by Jim). So my question is what is the best coolant in terms of reducing wear, corrosion, etc. I guess more specifically my question is, "Is there anything better than the Mercedes coolant?" Here is what I have found so far:

1) Porsche: Porsche coolant is green which the Mercedes guys say to avoid like the plauge (referring to old "prestone" green coolants I am sure). But Porsche must know what they are doing and wouldn't put in stuff that would corrode, right? (update: factory coolant is not green - it is pink, thanks jdaks)

2) Mercedes: Found a very convincing site that talks about mercedes brand antifreeze here:

http://www.thesaabsite.com/Coolantinfo.htm

The Mercedes bottle doesn't even say antifreeze on it, it says "anticorrosion fluid"!

3) Zerex g-05: Then I found this site that I think is saying that Mercedes coolant is the same as Zerex g-05.

"Hybrid OAT in this case means it has a traditional Ethylene Glycol-base, with a single OAT inhibitor and is moderately silicated. The version now being installed by DC, and tested by Ford, is based on the German BASF product, Glysantin G 05. It has been used in extensively in European Mercedes Benz and other manufacturer’s vehicles since the late 1980’s. New users expect that it will provide the 5-year, 100K miles coverage they desire. G 05 proponents believe that its moderate dose of silicates provide greater aluminum protection than a straight OAT while still being water pump friendly."

Here is the site: http://coolprofits.com/articles/antifreeze-coolant/G05-Glysantin.htm

Also the coolant discussions here support g-05 as a good option.

So I would love to hear what people think about which coolant is the best for longevity of the engine, water pump, radiators, plastic parts, etc. Thanks a lot and please let me know what you think.

update: just found another article which says to ignore color (similar to what Jim said in a post about it being just a dye). This article talks about collants used by various manufacturers:

http://findarticles.com/p/articles/mi_qa3828/is_199908/ai_n8867775

Mike

I topped off with factory Porsche coolant a couple months ago and I seem to recall it being pink...

jdaks, just got confirmation from another source that the factory coolant is pink...

Took out the carpets and found greenish orange in the reservoir. So needless to say I will be changing that out ASAP. My concern before was that I thought the Porsche factory coolant was green (because that is what I saw in the reservoir without the carpets removed) but now that I know it should be pink I am very comfortable using the Porsche coolant.

I also need to change the coolant on our Volvo and for that one I am thinking Mercedes coolant. Last time I bought it at the MB dealer it actually was $1 per gallon cheaper than the green prestone at a parts store which was amazing to me.

If your topping off your coolant use distilled water. If you flushing it use a mixture of distilled water and DEX COOL coolant.

What about Pentosin?
 

Lots of really negative info about dex cool out there but it is probably over-hyped by scurvy lawyers (in a negative way I mean).

I have found some parts stores that show only Porsche factory and Pentosin as the acceptable coolants. Pentosin is pink and appears to be factory fill for vw's and audi's (according to some forums anyway). Does anyone know if this is the same stuff as Porsche? I have a gut feeling that it is the same stuff.

We know that Porsche doesn't make their own coolant and what other brand is pink like Porsche's (excluding the japanese fills). Pentosin is German and appears to be used on VW's/audi (Porsche owns 31% of VAG I think)? Circumstantial evidence makes it look like it it is Pentosin but does anyone know more about it?

Pentosin is $9-10 per gallon vs. $35-$55 for porsche.

An example of the car manufacturer rebranding is the ATF for a volvo AWD. You can buy mobile 3309 ATF for $55 per case or Volvo 3309 (same stuff, different bottle) for twice as much.

Looks like pentosin gl12 is the same as porsche coolant
 

Found this parts store in Portland OR and they said it is the same which is what I have confirmed with 2 other parts stores. The cost of Pentosin (pink) is $11.42/gallon with free shipping if over $50 total. This compares to $51 per gallon for Porsche.

http://www.sjmautotechnik.com/

So I ordered 4 gallons and will use in my Volvo also.

Here is a picture of the official brew. Looks yellow to me.

I was told Porsche started using pink when the 987 came out, and that pink had been used in the Cayenne.

Yellow is now out and pink is in.

Looks like one of those exotic mixed drinks! If they have only changed once that's pretty good considering some other manufacturer's changes. I went to the volvo supply place yesterday and he said they have 7 different blister packs from Volvo that had seven sets of different plugs (brands I mean) for the same car (they all said Volvo on them). I wonder how much the changes are due to economics (cost of parts to manufacturer) and how much is actually due to trying to improve the product. With Porsche I would guess it is more the latter but who knows?

got pentosin today container is 1.5l not gallon for $11
 

so not enough savings to be worth it IMO. Might as well use porsche coolant. THe website says 1 gallon...