Back story -- I overheated on the track and warped the head. I had noticed that the water temperature was typically 220 F or higher. The problem was compounded by having the rubber ring coming off the water pump. Being concerned I started investigating.

I have discovered, for my 2008 S, a way to keep the water temperature at about 180-190 F. Turn on the AC AND have the fan on high. This gives be more room for heating before boiling over. It does not depend on anything else -- sport mode, highway speed, fan speed, etc. Since I did not want the AC compressor running at 6,000 rpm I just pull the AC clutch fuse when I take the car to the track.

Previously I had several cases where the car turned abruptly left or right -- rear end coming around. Since I started running with lower water temperatures this has not happened. I can only assume that the car had been overheating and blowing out some antifreeze -- making the read end slippery.

I can not speak for all years or models -- who knows when the BMW engineers change the firmware. But it is worth trying if you have overheating problems.

 

My old '86 944 had the same reaction. Driving from Lodi to South Lake Tahoe the water temp would go up and I would just turn on the ac and the
temp would drop. When turning the ac on, the electric radiator fans would go on.

 

The mini monitors the load on the engine and adjusts the water temps accordingly. Keeping the water temp higher is for economy and you'll find a boatload of manufacturers doing the same thing.

The mini will drop the water temps when you really get your foot into it. And contrary to your post, at least for N18 owners, the mini does drop the water temps to 185-195 when you engage sport mode.

I highly doubt your overheating issue has anything to do with "more room for boiling over", a la correlation is not causation.

If your car is expanding past the expansion tank and evacuating coolant, causing you to have a "slippery rear end", you have other issues.

 

Mine does, tested it several times. Sport mode on, temps went from 215-220 to 190 and then sport mode off, shortly back up to 220. I am a believer. Maybe different software in diff years affects.

 

2010s (N14s) do not change with Sport Mode. Under heavy load for several seconds will cause it to open the additional channel on the thermostat though and drop it to 185. Also the A/C trick, which I use when nearing home to cool it down quicker.

 

my 03/2012 build all4 does not lower coolant temp with the sport button on

it does lower the coolant temp over 4k rpm sport on or off, steady speed or hot rodding

also the a/c lowers the coolant temp

temp monitored via scangauge2

 

All our R56 MINIs cool down when under heavy load, it doesn't need the A/C on. The 2012/13 ones seem to cool down faster with sport mode on.