[RhoXS]

My 2011 28i has P245/50VR 18" tires.

What are the consequences if I replaced them with 17" tires other than the speedometer indicating a little faster than it does now for a given speed?

I currently have the Goodyear Eagle LS2 RFTs and certainly do not want to replace them with the same thing. By considering 17" tires it appears I can increase the number of tires to choose from.

I almost certainly would not change sizes so I am really more curious than anything else.

[Want the thrill]

Your title says 18 vs 19 but your thread says 18 vs. 17. Which were you actually referring to? I personally think 17's would look ridiculously small on the X3 if it were possible. The bigger the better IMO.

[brissim]

I assume you realise changing tire/tyre size also means changing wheels as well? And if you do change to a different wheel/tire size, as long as you keep the rolling diameter of the tire the same there will be impact on speedo or odometer. You just need to also change the tire aspect ratio.

ie in going from 245/50-18 to 17" tires, 245/55-17 have much the same tire diameter.

Likewise in going from 245/50-18 to 19" tires, 245/45-19 or 275/40-19 (ie the 19" M-Sports size) have much the same tire diameter.

Tony

[RhoXS]

Originally Posted by Want the thrill

Your title says 18 vs 19 but your thread says 18 vs. 17. Which were you actually referring to? I personally think 17's would look ridiculously small on the X3 if it were possible. The bigger the better IMO.

That was a typo, my error. The car has 18" tires.

Both 17" and 18" tires were provided in 2011 depending on the option packages purchased.

I was also erroneously thinking the subject dimension referred to something else. In other words, I did exactly what annoys me when other people do it and posted a question without really thinking about what I was asking. Thanks for the two responses above but this thread is, in reality, nothing but a waste of electrons.

[pokerface]

The rolling diameter of the tire must remain the same in order to minimize the impact to your speedometer, odometer, and to an extent your vehicle's handling too.

245/50/18 stock has a diameter of 27.65"
225/60/17 has a diameter of 27.63" .. less than 1% change. Alternately you could also try 245/55/17 at a diameter of 27.61"