I'm about to get new tires for my 2009 JCW and was wondering if I should replace the 205/45-17's that came on it with 225/45-17's on my 17inch challenger wheels that came on my car.

I'm not really familiar how the tire sizes work so any information will help me decide. I just don't want the tires rubbing if I went with the 225/45's

 

225 is how wide it is in milimeters, so you would increase the width by 10. Also staying the same size wall and increasing the width would increase the overall diameter. So you are making it larger which could possibly cause rubbing problems. BTW get lighter rims makes the world of difference.

 

That is what I don't want. I wonder how many inches wider they would be. I do want to get a set of OZ wheels someday but I just don't have the $$$$ for them right now. Thanks for you information.

 

I'm thinking the Tire Rack site has dimensions for most or all tires. Look at the diameter. If it's 1/2 inch bigger, do you have that much clearance? If it's 1/2 inch wider, do you have that much clearance. Some crawling, looking, measuring is in order before you pop for several hundred dollars for tires, mounting, balancing, etc.

 

Ronnie,
I ran 225/50R-17's for a while (until they were stolen) and I did have a minor problem with rubbing. Take into consideration that the 225/50R-17 is nearly an inch "taller" than the 225/45R-17 and the fact that my 09 R56 is lowered. Where it was rubbing was the very back end of the rear fenderwell, just above the top of the OEM mudflap and even then, it only rubbed when I hit a bump/dip that compressed the suspension. That tire diameter/width was just a little bit too much for my setup.

When they were stolen, I replaced those tires with a set of 235/40R-17's running a +45 offset wheel (these were all the same brand/model tire) and now, I don't have any problems with rubbing at any point in the suspension travel. The only time anything touches is when I make a left hand turn with the wheel all the way to the lock. If I back off the turn just a fraction, it stops.

Looking at the average numbers for the tire sizes and based on my experience so far, it looks like you can put those tires on and not have any problems with rubbing. You are increasing the diameter of the tire by about .7 inches and the width by a 1/2 inch or less. Now, if your car is lowered, all bets are off but a standard height MCS shouldn't have a problem with it.

Here are some numbers to look at and these are given knowing that each make/model tire will have some variations in size.

205/45R-17
Sidewall (rim to road) 3.6in
Radius 12.1in
Diameter 24.3in
Circumference 76.2in
831 revolutions per mile

225/45R-17
Sidewall (rim to road) 4.0in
Radius 12.5in
Diameter 25in
Circumference 78.5in
808 revolutions per mile

195/50R-16 (Typical OEM tire on the MINI)
Sidewall (rim to road) 3.8in
Radius 11.8in
Diameter 23.7in
Circumference 74.4in
852 revolutions per mile

Craig

 

Here are 2 tire size calculators. A 215/45/17 will be a better fit and will fill in some of the wheel well space. I have no idea if 225/45/17's will rub, since I've never tried them (I'm sure someone here has though).

http://www.1010tires.com/TireSizeCal...?action=submit
http://www.miata.net/garage/tirecalc.html

 

Might be too tall.
Why not try the already know to fit 235/40-17 on R56.

 

225/45/17 with a wheel et of 40 -- they fit fine -- very close but they fit. I ran them for about 10,000 miles.

Down side is they are big and heavy, which means they do not handle as well as lighter wheels and tire combination s -- and with the large diameter you loose a little bit of gearing hence a little slower acceleration but higher top speed.

So that is your trade offs -- bigger in most cases means heavier (is some cases a lot heavier) and larger diameter mean a change in performance as gearing is changed by the change in diameter.

The other consideration is side wall height, in general terms the taller the side wall the ride is better / smoother, as there is more cushion. The shorter sidewalls generally handle better as the tire rolls less laterally when cornering, but rides rougher / less smooth.


I much prefer a smaller lighter - diameter size wheel/tire combination.

Here is a link to a tire size comparison calculator that can be very helpful in this process.
http://www.discounttiredirect.com/di...foTireMath.jsp

 

I'd agree with the 215/45 being a better choice as it will fit and it will be lighter. The 235/40's that I have are mounted on 7.5" rims which is a little narrower than suggested but they fit, they ride really nice and I haven't had any problem with them on the autocross.

When I was trying to figure out what tire to go with, I made a simple excel spreadsheet. I put the make/model tire and the sizes. I sorted them by the diameter with the OEM tire size highlighted in yellow. In the end, the 235/40R-17 was almost exactly the same diameter as OEM (I think it was about .3 inches larger) so I knew it would clear the area that was rubbing before. The spreadsheet let me "see" how each of the tire dimensions compared to OEM so I could figure out which would fit best.

Have a great time!
Craig

 

Yes, I really prefer 215/40-17 for OEM wheels for myself, but I got R53 and cannot fit 4X4 tires on it.
Just thought based on OP's desire for fatty tires (225/45-17) he mentioned, that he wanted big donutty tires. That's why I suggest 235/40-17 which is not as fatty or donutty as 225/45-17 but it is big and wide decent sidewall plus it fits and performs much better.

 

Go to the miata tire size calculator. It will show comparisons and speedometer error.

 

so i did install nitto neogen tires. 225/45/17. they fit. no rubbing, no problems .i dont really like the way they look . too much side wall for the mini. on my 01 vr6 they look great. the car/steering does feel alittle heavier. the steering floats a bit. fuel and acceleration i feel is less. at higher speeds the car feels alot more solid. the ride is less rough (i dont mind the rough ride anyway). so if your car isnt lowerd this tire size will fit. they are wider and it looks great from behind. guess i will buy lower profile/lighter tires for it and put these on my corrado.

 

The 215/40/17 tires are nice wide low profile tires and you will get the width without a tall sidewall.

 

yeah man. i found this page after i put the tires on. im not that disatisfied. i got the tires with rims from a friend for 400 bucks so all in all it was a good deal. but now i know what size looks good on the mini.

 

I have JCW rims and I believe they are 18x7.5. I have 205/18-40 now. I was thinking of changing my run flats with: 225/18-40 (rear) and 215/18-40 (front). Would this set-up be okay without any rubbing? Anyone have this set-up now? if so, please post pics. The MINI is not lowered yet. Prolly won't lower it until mid next year.

Thanks in advance.

 

I'm running 215/40/17 on my Challenge wheels, they look pretty decent. This pic should give some idea of what it'll look like. Thinking about doing 215/45/17 for my next set of tires for better comfort.

 

Your stock 205/45-17 tire size is the best if you can find a tire that works for your needs.

225/45-17 is wider and taller than stock and while it will fit the stock wheel and wheel well the clearance is minimal and under full load in the rear seat you might rub. Taller tire means speedo error and higher road clearance with an oversized tire look. Plus they are heavy.

215/45-17 would be OK and 215/40-17 is smaller tire diameter than stock with a stiffer low profile sidewall that is often firm riding and risky if you have a lot of potholes in your roads.

Anytime you lower your suspension you have much less clearance so 225/45-17 would be out. 215/40-17 might give more clearance in that case.

 

I think you mean 225 in front and 215 in rear.....MINI is Front Wheel Drive!!
And the MINI has engineered understeer to begin with, wider rear will exacerbate it even more, while thiner fronts combined will make it downright disastrous.

 

While it is possible to do what you mentioned it would be best always to use the same sized tire on front and rears since your wheels are all the same width and offsets.

Running different width tires is possible with a staggered setup seen on some sportscars but does not apply to the MINI easily and for street use.

Best fit would be with 215/40-18 front and rear. This size fits 7.5" wide rim perfectly and weighs less. There are some decent tires in this size-
http://www.tirerack.com/tires/TireSe...r=18&x=59&y=14

225/40-18 is possible front and rear but is tall at 25" tire diameter. Using stock suspension there should be enough clearance but if you did lower your MINI you'd be at risk for some rubbing under full load of rear passengers and their gear.

You don't want to run these different size tires mixed because the tire diameters are not the same and the 225/40 would be higher up in back. A wider tire as mentioned for the rear would be great if the MINI was RWD or even AWD.

 

Here's my thoughts:

225/45/17 won't work very well. 225/40/17 would be good, but I think they're too wide for our stock 17x7 wheels. It's also an odd tire size, tires are rare.

215/45/17 I think is ideal since it fills in the stock height wheel gap a little better and it should make the speedo read accurately. 215/40/17 looks better when lowered and the speedo should read about the same as stock. With stiff sidewalls, I think potholes won't be a problem with the 40 series. I've ran my 40 Series Star Specs for 23K miles and have had no problems and my commute has some crazy potholes which I hit fast on occasion.

 

I have a 2011 Mini S and am going to change my 205/45/17 run flats, I want a little wider look if possible. I have sport springs and put about 1/2 inch spacers on. I am thinking 215/45/17's or 215/40/17, the 40's may ride a little harder but they can't be any worse than run-flats!! Any advice?? Thanks..

 

I have 235/40/17's on 7.5" wheels with Swift springs ,the rears rub just a little on bumps.

 

235/40 is shorter (24.4"), and that certainly helps clearance (vs 25.0")

 

I am not going to change wheels, I like my stock black web spoke 17s, they are the ones with the silver outside rim, but was just wondering how wide a tire I can make work. I am thinking now 115/45/17 is about as wide as I better go. With spacers I also wondered if that would increase my ability to go wide but from what I have found out if I do it also increases the hight of the tire which throws off my speedomoter.

 

You can't go much wider than 215mm because you are lowered. Rubbing happens in the back along the inner upper wheel arch plastic. If you have a full load or go over uneven dips you can rub. Adding the spacers makes it worse.

Making the rear camber more negative will help clearance a little but increase oversteer if you turn fast. You also can wear your inner rear tires faster for street driving.

Best tire for your stock wheels right now would be 215/40-17 which will fit because they are less tall than stock tires due to lower sidewall. The 40 series sidewall is very stiff so if you go over potholes and bumps it will be jarring. If you have smooth roads then it's fine.

The spacers have nothing to do with tire height or diameter- it does not affect speedo error, only changes in tire diameter do that.

Good example of 215/40-17 tire is-

Extreme summer tire
Dunlop Direzza Sport Z1 Star Spec
200 treadwear $177 each

Max Summer tire
Continental ContiSportContact 3 (closeout)
280 treadwear $109 each but only a few left, alternate size 215/45-17

Continental ExtremeContact DW (a much better continental tire)
Best size is 205/45-17 $125 each
215/45-17 $127 each
340 treadwear

Personally I'd pick a tire first then the size not the other way around. Looks will only be slightly wider with the 215mm wide tire. Lower side profile will look more aggressive but is more jarring on anything but smooth roads. The ExtremeContact DW is a very smooth riding tire good for street use.

A good value Max Summer tire would be-
Sumitomo HTR Z III
215/45-17 $95 each
300 treadwear, decent street manners

The best Max Summer tire available would be-
Michelin Pilot Super Sport
215/45-17 $166 each
300 treadwear

Note 215/45-17 is slightly taller than stock tire diameter of 24.4". It does vary a little but often is 24.6 to 24.7" tall. Rubbing in back is possible with a lowered suspension. Some trimming of the inner wheel arch plastic would allow for more clearance.