Yea, that matches my math- but at 15.5% change it would Be more like down to 2200 from 2600.

I believe I’d be content with the 50i diffs alone- I use my x5 for a decent amount of long distance maxed it towing. The 3.15 diff would bring my 6th gear to a much lower cruising and would make my “new” 5th gear about 5% shorter than my current 6th. I wager I’d be cruising a lot of the time in 5th while hauling long distance, but I’m not worried about that. Basically an equivalent situation regardless.

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'10 X5 35d- 279k mi, deleted and DUDMD stage 2, daily and tow vehicle
'01 330i- Drift car: SLR Super angle, BC coils- keep it simple
'07 335i 6mt - Sold @ 171k miles- stage 2 daily commuter for 2 years