[Wayne 962]

Okay. I think that the extended-life coolant makes some compromises on performance for life-extension. Since you're in a cold environment, I would stick with the normal stuff.

If you're not the original owner, then I would certainly do a full block/radiator flush.

I'm sure that if you wanted to use the extended stuff, that there would be warnings and labels on the back of the bottle, for what preparations you would need to clean out the old stuff. I personally haven't used the extended-life coolant.

We can certainly get the OEM coolant no problem, however, BMW obviously doesn't make it's own coolant - they buy it from elsewhere.

The main concern is indeed particulate in the coolant. If you flush and replace your coolant every 2 years or so (and don't add tap water), then you should be perfectly fine with off-the-shelf coolant.

-Wayne