[e92_m3]

I have a question for both motors.

How about reliability issues for the N20? In 15-20 years considering both the 528i 4-cyl and 6 cyl were not abused and driven pretty much everyday, at some point the N20's turbocharger may need it's bearing changed or even worse it's turbocharger replaced.

In 15-20 years the the 6-cyl may also have gone through reapairs like alternator or starter being changed, etc, but the parts and labor spent on getting a replacement turbocharger on the 4-cyl will be very expensive compared to the 6 cyl.

My dad has a 1990 525i and it still runs good to this day. The only repair that was done to it was to replace it's battery and starter. If that was a turbo, the turbocharger may have already seized considering it has been 22 years since the car was purchased.