Quote Originally Posted by CitizenKane View Post
Didn't the 2.5 and 3.0 525i have basically the same bhp anyway?
not really, the n53 used in the 25i just didn't have the 3 stage intake manifold and the throttle body was restricted to only open to 75% at WOT. With a tune, they're good for 260ish bhp, with the 3 stage manifold and a tune, they'll do the same as a 30i.