Hi all, hope you're all ok and welcome to my first post!
I have recently bought a 1999 E39 523i, 2.5ltr petrol (first BMW I've owned).
After doing a bit of home work I found that the later 2.5 from the 525i has 20bhp more, as you will know 170bhp to 190bhp.
My question for you is that is it possible to upgrade the earlier 2.5 to this spec? While I apprieciate I could have it mapped I wondered if there was a an ecu swap etc that could be done as the car is all original with only 2 owners and completely untouched.
Many thanks, regards Kev.