Originally Posted by Surly73
You should use G-48, which is what BMW coolant is. And there doesn't seem to be any handy sources of G-48 that are significantly cheaper than the dealer, so you might as well use dealer coolant unless it's really hard to get.
G-48 has plastic compatibility specs which are different from some otherwise very similar coolants.
You are probably right. I am more concerned about using the right oil then the right coolant (don't ask me why). I have been using that stuff for years, even on my e46 which lasted to 200,000 miles. If anything goes wrong I will post an update.