G-12?

[CosmicFlash]

What's the deal with this coolant? Is VW/Audi the only maker that uses it? VW says it's "lifetime"
I read in Car & Driver that it's the same stuff semi trucks use that go 300-400,000 miles on a coolant change and that is why it's supposedly "lifetime". The article said Zerex is going to be coming out with a retail version in the future as more of the cars get on the road. I've got a 99' Passat with 111,000 miles on the original coolant. What do you think?

Thanks!

 

[CosmicFlash]

quote:

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Originally posted by CosmicFlash:
What's the deal with this coolant? Is VW/Audi the only maker that uses it? VW says it's "lifetime"
I read in Car & Driver that it's the same stuff semi trucks use that go 300-400,000 miles on a coolant change and that is why it's supposedly "lifetime". The article said Zerex is going to be coming out with a retail version in the future as more of the cars get on the road. I've got a 99' Passat with 111,000 miles on the original coolant. What do you think?

Thanks!

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Oops! Edit. I just read the link to the C & D article. It's G-5 they are referring to. Ok so what's the difference between G-5, G-11, and G-12? Confusing?

 

[Ferb]

I'll take a stab.

G-05 is manufactured by BASF for Ford's and DaimlerChrysler's 5yr/150k coolant. Low silicate hybrid organic acid technology. This in contrast to the silicate free OAT of Dexcool.

G-11 is a Pentosin product that also uses HOAT additives, and could provide 2yr fill.

G-12 was an upgrade of G-11 to deal with a need for lifetime fill. However! G-11 and G-12 are not compatible at all. Even the head gaskets soaked in G-11 would be eaten by the newly added G-12.

Anyone care to update/edit my brevity?

ferb!

 

[moribundman]

G11 is the blue/green pre-'97 VW/Audi coolant. G-12 is pink/red and is made by Pentosin. You can find it sometimes a NAPA stores. The dealer sells G-12 made by Zerex. Never mix G-11 and G-12, or the coolant might gel. It is safe to switch a car from G-11 to G-12, but the cooling system needs to be thoroughly flushed.

G-12 is offically a "lifetime" fluid, but if you have any metal parts (waterpump, thermostat, etc) in the cooling sytem replaced, then you need NEW G-12. Old G-12 does not contain enough corrosion inhibitors to thoroughly protect any new metal parts. I'd change the coolant when the timing belt and waterpump are done, at least once every 4 years. I also recommend using destilled/demineralized water for mixing coolant.

 

[Lance]

The G-12 coolant in my VW has done well for 120K miles. I recently replaced the water pump at the above mileage, along with the water pump. Wow, these cars last a long time!

 

[moribundman]

Lance, the G-12 needs to be replaced each time you have any metal parts in the cooling system replaced. The old coolant does not have enough additives to sufficiently coat the new parts. That will result in corrosion. If you were to never change a waterpump or a thermostat, then you could keep using the same coolant for the life of the car.

By the way, 120k miles is a lot of miles on a VW waterpump. I would change the WP (if it's driven by the timing belt) and the timing belt (tensioner and roller, too) earlier (every 70k miles or every 4 years) to prevent a blown interference motor.