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[Rocklicker]

Hi All,
Has anyone purposefully run a slightly larger rolling diameter? I'm tossing around the idea of getting 18" summer wheels but keeping the same sidewall profile for a larger rolling diameter.

Possible benefits:
1. The BMW speedometer won't lie anymore. I've calculated mine at ~7% faster than actual against GPS. All BMW's intentionally do this to some degree, and it's really annoying.

2. Less wheel arch gap, without dropping (I have an XI and shitty roads)

3. Maintain 17" cushion with 18" rims (shitty roads)

Possible cons:
1. Affects gearing. I have a 328 with 6MT.
2. Raises the vehicle a smidge.

The gearing thing is real, because to target enough increase in diameter to cancel out the speedo lie it will create taller gearing. I don't care about 0-60 but I do care a lot about driveability. I can run numbers all day long but first hand accounts are way better!
Raising the vehicle a smidge I don't care about, as it's an XI wagon. If it gets too high I'll just put tan plastic cladding on the bottom third of the car

So has anyone done this? Any pictures to share?

[Volasko]

Aside from everything you mentioned (which are all true) I think the biggest issue may have to do with wheel clearances inside the arches. I would think that on large bumps (enough to compress the suspension fully) you would have a lot of tire interference with the inside fender linings. Also full lock steering could cause the same problem. I don't know this from personal experience, but its the main thing I would think would be an issue.

[Rocklicker]

Excellent point. Seeing what some people get away with on slammed suspension makes me hopeful on that front though!

See sig

[Rocklicker]

Awesome, that's pretty much what I was thinking of. Got any pics of your car? (I can't find a user gallery feature?)

Unfortunately your car would be apples to oranges on the gearing issue.

http://www.e90post.com/forums/showpo...9&postcount=11

Looks a bit different now given that I added spacers (10mm), M3 LCA, sp perches up front and went to a 15mm spacer in the rear.

You should be able to use google image search to find other user examples as well.

[Rocklicker]

Looks pretty good, IMO. Makes me want to put a spacer on the rear of my square winter setup. I wouldn't mind the extra fraction of an inch of ground clearance either, this grocery-getter trim already has a worse breakover angle than my last car, a very non-pedestrian Mazdaspeed 3.

[330xtrai]

I actually ran a super huge set on 19s 245/45 275/40 definitely don't recommend as I wore the hell out of my fender liners on full lock and bumps , the front mainly.i was on max height kw v1 . you could probably run something slightly smaller rolling diameter and get away with it.

also depends on your suspension.