Anti-Freeze.

[X5Cat]

Replaced my Behr radiator several months ago, due to leak between the plastic and aluminum. I don't think it said China, so I assumed it was from Germany. That's when I switched to the Prestone.

[Riggodeaux]

The most specific discussion of "why bmw antifreeze?" I've seen was an article in Roundel about 6-7 years ago. I can't find a link to it, but here is a thread in the E46 forum summarizing it [with the comments making the normal arguments why its the same as Zerex GO-5 .....]: The "why BMW only" coolant question answered - E46Fanatics
Since mine has the fluid/thermostat/etc. changed about 20k miles before I bought it, not something I have to think about for awhile ....

[racingbmwm3]

I looked up the Zerex G0-5 coolant from that thread on amazon, and it must be the same stuff BMW re-brands because it is also $24/gallon (undiluted). I'll stick with the BMW stuff Pelican and Bavauto sell.

-edit-
Napa sells it also, for $17/gallon. Description says it's yellow though. So, if I do my coolant flush this spring, I'll end up with a greenish final result (assuming I can't ever remove 100% of the old coolant). I'll pay the little bit of extra for the blue

[bcredliner]

I don't know what Zerex prices are but to me price isn't the issue here. If BMW provides the only 'safe' coolant that's what the vast majority of us would purchase.

I see anti-freeze as a simple formula that would quickly be reverse engineered to be able to serve a notable size market. If German vehicles, or just BMW, had a monopoly on coolant for their vehicles because it was so unique and necessary, there would be appropriate coolant on the shelves labeled specifically for those vehicles.

We don't have unequivocal performance documentation of more complex aftermarket parts we purchase for our BMWs. BMW recommends the oil we use and look at the discussions that generates, pages and pages of other preferences. I use Royal Purple oil and I don't use a BMW filter. How many of those out there would say it is not suitable or the wrong stuff, or, if bold enough, would tell me I am nuts?

Because of the importance of the brand name of companies like Zerex and Prestone, and the amazing amount of communication that now happens in a matter of seconds, verification of the accuracy of technical information and marketing lingo disseminated is a critical issue. Of course there are mistakes still made but I don't believe any company could get away with a coolant offering this long and not have a multitude of threads on BMW forums ranting about how a particular coolant destroyed their cooling system---there would be no question by now.

Even 20 years ago, companies in for the long haul were very brand name sensitive. While marketing was tasked with finding ways to communicate their products in the best light possible and at least appear to be better than competition, they were as careful even then.

In my case, an Autozone is 5 miles away and the nearest dealer is 15.

Advance auto sells Prestone extended life coolant for $13.99 a gallon undiluted. At 70 percent coolant it provides protection to -84 degrees which should be good enough for most places this winter. At 50/50 mix protection is at -34 degrees. This is per the website.

I don't think we need a prize winning chemist to draw our own conclusions about antifreeze, ever had a doctor miss the mark?

[X5Cat]

Originally Posted by bcredliner

... ever had a doctor miss the mark?

A doctor buries his mistakes, a lawyer appeals his, and an engineer's hits the newspaper.

[StephenVA]

and a mechanic keeps getting them back like zombies (some parts dead some parts alive) now fix it!

[TiAgX5]

Originally Posted by X5Cat

A doctor buries his mistakes, a lawyer appeals his, and an engineer's hits the newspaper.

I think that's why doctors and lawyers refer to their job as a practice......perform an activity repeatedly or regularly in order to improve one's proficiency.

Engineers "practicing" on the job are unemployed in no time!

[racingbmwm3]

well, as an engineer, that is why after performing all the calculations we add in the factor of safety. Doctors don't get to buffer their work tolerance.

[bcredliner]

The shortfall of an engineer may hit the newspaper but his name won't.

I agree that engineers intend to add a safety factor though it often doesn't prove out in the testing phase. I think doctors constantly buffer their work, it's just in the other direction that they call a conservative approach.

[X5Cat]

Optimist: The glass is half full.
Pessimist: The glass is half empty.
Engineer: The glass is twice as big as it needs to be.

Yeh, I'm another one!