[ScottE]

Hey all,

Took my Xdrive 28i in to dealer today for its first oil service, a rattling headliner/sunroof, and an ASS reset to last-used-mode. Routine stuff. Got a loaner for the day... nearly exact spec as mine ... an Xdrive 28i with 8K miles. Drove it back home.

Wow.

Nearly everywhere in the powerband, the loaner feels noticeably quicker - at part throttle or WOT. I consider my butt dyno to be fairly well-calibrated, so I'm scratching my head here. I know there can be slight variations from car to car, but the difference seems too extreme. And I'm pretty sure this isn't anything related to the 'ol sluggish throttle/turbo lag issue that's been brought up.

My service advisor said he's keeping it overnight for the ASS and rattle work and would look into my perceived power claim. He mentioned that a tech might run another comparable loaner and my car back-to-back to confirm. "Perhaps it's a programming issue", he says. Dunno, I guess I'll know more tomorrow. I'm almost crossing my fingers I get a "you're right, it's not making full power" diagnosis and then a fix, whatever that might be.

In the meantime, I've done some low-level searches on the matter but nothing related pops up. Has anyone else experienced this? Any thoughts on what might cause this? (Other than senility).

Thanks in advance.