Ditching the runflats and getting 17" rims with non runflat tires for my 2nd gen R56 cooper s.

WHat size tire do you recommend? my dealers give me different answers.
My current runflats are 205/45/17.

Do i stick with that or go 215/45/17?
CAn i go 205/40/17? (dealer has a mad special on these)

im clueless with this and the effect it would have.

thanks

 

I am running 215x45x17 on 2 Clubman. One is lowered on TSW springs and has 17X7 wheels. The other has 17x7.5 wheels. I have no issues with either.

 

Tire calculator.

If possible, stick with an overall diameter within 2% of original, to maintain gear ratio, speedometer accuracy, and suspension geometry.

--Dan
Mach V

 

If you have stock suspension then-

First choice is 205/45-17
2nd choice 215/45-17 which is a little taller than stock but will fit OK.

205/40-17 is smaller tire diameter than stock and isn't the greatest choice due to stiffer and shorter sidewall height which can make for a rougher ride especially on roads that are not perfectly smooth. Also it looks smaller than stock and has less load capacity which means you don't want to load up people and cargo and go racing around.

215/40-17 is also possible, smaller tire diameter than stock and works with a lowered suspension but is stiffer riding due to lower sidewall. Usually the same tire in this size will weigh less and cost more.

Tires with 40 series sidewalls will tend to be more performance oriented and wear faster, usually summer tires. 45 series tires can come in all season Ultra High Performance or other tire classes.

 

thanks, thats alot of help, think im going to stick with the 205/45/17 just to be safe and keep it as stock as possible, if i wanted to lower the suspension later would these still work??

 

Anytime you use a tire that is wider or taller than stock you have less clearance in the wheel well and less drop is possible for lowering the suspension later.

205/45-17 is fine and will work with a slightly lower suspension. Any tire that is taller than about 24.5" will give you more risk for rubbing but it can depend on which rim you use. A stock wheel is fine but aftermarket or wider rims can place the tire further outside the wheel well where it can rub on the inner plastic wheel arches. Sometimes trimming the arches on the inner side with a dremmel tool will be needed if that happens.