Ikinos (welcome!)
BXdriver virtually everyone of these chip suppliers (
http://f15.bimmerpost.com/forums/sho....php?t=1088491) has a chip for the 25d. The table is for 30d/35d, but the % gain in should be comparable for the 25d.
It is not a free lunch, i.e. not without risk, but the consensus amongst those who have had it (and five experienced dealer service reps I spoke to last week) was that if you don't turn it up all the way and try create magic, it should be safe and without check engine light errors.
I am very interested to see your MPG shots in my MPG thread.
http://f15.bimmerpost.com/forums/sho....php?t=1081659
EDIT: example with one chip, showing performance comparable to 30d/35d:
http://www.cpa-chiptuning.de/en/chip...uning_2642.htm