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Old 01-04-2013, 11:58 AM
bobdmac bobdmac is offline
Older than old school
Location: Oaksterdam, Yay Area
Join Date: Feb 2011
Posts: 4,414
Mein Auto: 2001 540i/6, '90 k75s
Originally Posted by Fudman View Post
The tire diameter for a tire mounted on a 17" wheel should about the same as a tire mounted on a 16" wheel, irrespective of tire width. Otherwise, the speedometer would need to be recalibrated. The difference in tire sidewall height is compensated by using a different aspect ratio when sizing the tire (235/45-17 vs. 225/55-16) to a different diameter wheel. Hence, the BMW guidance does not make sense. The tire clearance should be about the same if you are staying within the recommended tire dimensions.
I'm not sure, but I think the issue is the clearance between the tire walls and surrounding metal parts such as fenders and suspension components. The cable chains should work, however. Another option is Spikes Spiders

BMW--giving new meaning to the phrase "disposable income."
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