The 17" Silver Cosmos Spoke:

17" x 7" wheel

205/45 R17 tire


The 18" Cone Spoke:

18" x 7.5" wheel

225/45 R18 tire


Why is the "45" profile of the tire the same for each wheel? Doesn't this mean the 18" tires have a greater circumference than the 17" tires, and the speedometer will show different readings for each tire with the car at a constant speed?

Could this be a typo on the miniusa.com site and the correct profile size for the 18" wheel might be "40"?

Thanks in advance...

 

At tirerack, I see, for instance, that on a Potenza RE050A
a 205 45 R17 does 857 revs per mile and a 225 45 R18 does 804 per mile. The 18s will read slower.

 

Isn't there a tweak for the ECU that the mfg can put in that does the calculation for speed/distance? They then plug in the value for the tire size so things come out right. If you've got a GPS you can simply check the speedo against the GPS and see if they agree.

 

Typo for sure. The 225/45R18 is the spec-ed tire for R60/61. Way too fat for the F56. 225/35R18 is the closest one to stock OD, slightly under but really close... although i'm not sure if such size will work without rubbing or not.

 

MINI R56 speedo is off +4mph from factory. Always drove me crazy that it is that way.

 

Guess I'll have to wait until my car arrives before ordering new tires.

 

Historically, speedos have nearly always been off. Car magazines routinely showed that they were 5-6% fast in their road tests. GPS is only making it more more widely known. Of course, tire wear, inflation and tire brand are also factors.

 

Yes, it's an error. Here is the MINIUSA price sheet: http://s3.motoringfile.com.s3.amazon...ng-1-30-14.pdf

The correct tire size is 205/40 R18

All of the tire sizes 15"-18" are the same as in previous generations.

 

Thanks so much, rkw! Tires ordered.

For anyone interested, tire rack.com is offering a $70 gift card for eligible Michelin 4-tire sets purchased from today through the first week of May.

 

rkw, not sure if you noticed, but all the 17" and 18" tires are showing 205 width...perhaps that could be a typo as well?

Maybe the correct size is 225/40 R18?

 

Never mind...forgot and just confirmed you were correct via a thread I started a while ago.

https://www.northamericanmotoring.co...tire-size.html

Thanks for all your help!