I have a 2007 cooper s with the JCW package. I have seen a lot of posts about 17” rims, but when I take a tape measure to mine, they read 19.5”. I live in an area where road maintenance is more a suggestion than an actual event. Five or six times a week I bottom out or hit an area by a bridge that damn near rips the rims off the car. I need more rubber. Period. I can’t put bigger tires on these rims due to the body. My question is, what are the ramifications to changing to 16 inch rims so I can get 3 inches more tire? Will this screw up any of the computer systems? Will it tank my mileage? Give me cooties? Thank you for any information.

 

I believe the JCW are 18" rims. You can reduce teh size up to 15" without any real ramifications to speedo. Most of what you will find will be 17" or 18". Even 17s will give you more space.

 

The whole trick to keeping the computer/speedo correct is to keep the overall tire diameter about the same. Here are some examples of tire diameter:
205/40-18 = 24.5" (sidewall = 3.23")
205/45-17 = 24.3" (sidewall = 3.63")
195/55-16 = 24.4" (sidewall = 4.22")

 

15 inch rims may not clear the gen 2 front brake calipers. 16 inch rims may not clear the JCW brake calipers.
Here's a good chart from the other site's wheel/tire FAQ page: http://www.mini2.com/forum/faq.php?f...wheel_fitments
Scroll up and down on the same page for lots more good information.

If you have a 2007 gen 2 MCS with the full factory JCW package, you may only be able to go down to 17" rims.
Try 17x7 rims with +38 to +46 mm offset and 205/45/17 (stock size) or 215/45/17 for a little more sidewall than stock
while still being close enough to work without problems - avoid runflat tires as their stiff sidewalls will make the problem
you're trying to avoid worse.

If you have the JCW engine package but the regular non-JCW calipers, you should be able to go down to 16" rims.
16x7 with about +42 offset would be good (stock wheels offsets are 16x6.5 +48, 15x5.5 +45, 17x7 +48, or 18x7 +52),
with 205/50/16 tires (slightly shorter, but good selection), or 195/55/16 (stock size, but would avoid the stock runflats),
or 215/50/16 (same as stock diameter) or even 205/55/16 (a little tall, but should work).
Make sure the rims can take a 14 mm diameter bolt, some wheels are drilled for 12 mm bolts that the gen 1 MINIs used.

 

You know Cristo, I didn't even think about the calipers and you are right, the 15s won't fit.

 

Thank you for the information! Is there a trick to determining what type brake calipers I have? I bought the car used from somebody who had it tricked out to race. I suspect that they beefed up the brakes.

 

Do the fronts say JCW on them? If not, do they have some other logo? I guess you could take a picture and post it up.

 

The fronts say:

5592
B (or 8) can't tell
276-7
MINI

 

Are they red, from the factory?

 

Seriously fire engine yellow. I have black spoke rims and on sunny days it looks like I have been booted. I can say with absolute clarity that these suckers are yellow. I do not know about factory. I am the third owner of this car.

 

Post of photo of your front wheel, so we can see what wheel and brakes you have.

--Dan
Mach V

 

Hope this loads.

 

Those are the stock R56 (Gen 2 MCS) brakes painted yellow. They are the same as the JCW brakes on the R53 (Gen 1 MCS). The R56 JCW brakes are larger 4-piston calipers and larger rotors.

 

So... is this going to keep me from being able to use a 16 inch rim? I was looking at the 195/55-16 as a replacement for the 205/40-18 I have now.

 

That should be fine.

 

As long as those are the regular S brakes, 16s will work fine (that's the stock rim size for the R56).

 

I have a 2011 Cooper S with the sport package and 17 X 7 rims, I dumped the the 205 45 17 stock tire and went with 225 45 17.

It's worth checking out...we have some bad roads also.