I'm looking at replacing the stock 17x7 wheels with some aftermarket ones. Currently the car is on the stock sport springs with newly installed Koni yellow dampers (I am considering swapping the springs in the near future for either TSWs or NM alphas). I've decided I'd like to go with 215/45-17 tires, but I'm a bit stumped on the wheel width and ideal offset.

I'd like to widen the stance a bit to fill out the wheel wells a bit more, but I want to avoid rubbing in the rears now and in the future, should I make the move to go lower. I've read around about what offsets people are running, and it seems like for 17x7 rims, E37 is the sweet spot. Based on that, I assume that for 17x7.5, E42 will give me about the same push wide, but only lose 1mm inner clearance.

The current 205/45-17s are a bit stretched on the 7 inch wide rim, so my thinking is that a 7.5 inch rim will do the same for the 215/45-17, preventing the tire shoulder from being too square and rubbing.


Anyone have any experience running 7.5 inch wide rims on an R56? What offsets and rim widths are people running with 215/45-17 tires? Do you have any rubbing?

 

Compared to OEM 17x7 et48:

17x7" et 37 will poke out 11 mm more which is fine. You can also use et 42 which is commonly found.

17x7.5" et 42 will be 0.4mm closer to inner suspension and poke out 12.4mm more which is fine.

Anytime you lower the suspension (lowering springs) you reduce clearance for any wider that OEM wheel or tire. The less the poke the better, you can always trim wheel arch plastic where it might rub (under load or going over dips).

205 or 215 mm wide tire sizes will fit 17x7" wheels just fine, you don't have to be looking for wider wheels and the selection of 17x7.5" wheels is less than with 7 or 8" wide wheels.

The wider the wheel the more it will weigh, what are you trying to use the wheels for? If you care about performance then most times 17x7 will work and usually cost less and weigh less.

Tire shoulders may be a little more square on the shoulders if the tire itself is designed with generous thick or wide outer shoulder blocks as you will find on Max or Extreme Summer tires. If you look at All Season tires the shoulder blocks are more rounded, try Ultra High Performance All Season tires if you want that.

 

Thanks for the info minihune. My immediate use for the wheels is street driving.

My thought about going with a wider rim was based on attempting to mimic the same stretch that the stock tires have on the stock rim width (205 mm wide tread on 7 in wide wheel rim) to maintain the same or similar handling characteristics. My concern with moving to a 215 tire is that it will make the steering response more muted now that there is more rubber being stretched less across the wheel rim. On the other hand, maybe I'm making way too much of the extra 10 mm of tire and should just stick with a 205 section tire.

Looking forward, I'd like to get a wheel that can possibly serve as a track day wheel, clear a willwood bbk, and not rub with about a 1-1.25 inch drop. Not that I'll actually do any or all of those things with the car, but I'd like to leave the options open and not paint myself into a corner.

Ultimately, it looks like if I try to keep the inner clearance as close to the same as stock and keep my outer clearance within about 12 mm I should be fine.

 

Anyone running 17x7.5 rims with 215/45-17 tires on an R56? I'm looking to pull the trigger very soon on this.

 

I a m running,since brandy new, on a set of sumitumo htrz 235(yes-no typo)/40/17 on a set of Rota RB's 7.5 wide with ET45. Car is lowered 2" on springs. JCW big brake car that uses 12.5 spacer in front ,none in rear. NO PROBLEMS and I absolutely hammer this car.
Total expense thru wise shopping (wheels, tires, shipping,springs, mounting, balancing,wheel alignment not necessary,etc.)was about $800 . I do my own labor.

ISAMIN
,

 

I've been running 215/45/17 Michelin PSS on 17x7.5 et40 with no problems at all. My car sits about an inch lower than stock too.

I'm wondering if I can pull off 225/45/17's on 17x7.5 et42. I was just actually PM'ing Minihune about it. He seems to have some serious wheel/tire knowledge!

 

I've been running it all summer. You may feel that the car picks up a tiny bit slower as the overall diameter is slightly bigger. But your speedo will be more accurate.

Please note that every tire has a different section width and tread width even if they say they are 205 or 215. Some have a very square profile and others are stretched.

 

Hello,
Im also looking to run 215/45/r17 and I also have 15mm spacers all around. Is there a reason that you don't run the spacers on the rears? will it rub? Thanks