[gpraceman]

This thread was very helpful for me. I have a Z4M with almost 60K miles. I have been changing out all of my fluids for Inspection II. While changing out coolant is not on the Inspection II list, not knowing the full maintenance history on this car, I feel better about changing out all fluids, including coolant and power steering.

I was only able to get out about a gallon of coolant. It looks like the M's only have a 8.0L/2.1gal capacity, so about half the total capacity drained out. I was tempted to do a 2nd flush with distilled water, but my old fluid was looking pretty good, so I just did one. I have quite a bit of coolant and distilled water left over. Those with M's only need to get one gallon of coolant. Two gallons of distilled water to do one water flush, three, if you want to do two flushes. The other difference with M's is that there is only one plastic drain plug. There is not one on the expansion tank.