I have an X3 which loses power especially uphill. The car was serviced about 10 months ago when I bought the car but not serviced by BMW. Over the last month or so I have noticed this power loss on an intermittent basis - it gets to about 40 / 45 mph then just hangs there. If I change down it does not make any difference.
I've been told that short trips is part of the problem but recently on a 50m M4 trip it made no difference and it seems to be a permanent problem.
Before I head to my BMW garage, is there anything relatively simple that i should look for please?