right now i've got the stock v-spoke 16" with 205/50/16's. i've been thinking about going to a 15" wheel with et40 offset and 225/50/15's. the diameter is about the same but i'm concerned that i may rub on the inside of the fenders due to the slight increase in width. does anyone have this set up on a lowered mini? i'm runing M7 springs which lowered about 1.2" all around. i can just stick my fingers between the bottom of the fenders and the tops of the tires. these are the wheels i want:

www.edgeracing.com/wheel/27/

 

I briefly tested this size BFG KD at an autocross on my 15x7.5, +43, SSR's. It was on high grip concrete and I was on KW coilovers. Unfortunately I don't remember what springs rates I was running at the time or how low I was, both have varried with time and I'm down 2" now but with stiffer springs than I was using when I got my first KW's. I did have some slight rubbing though. More negative in the rear, a big rear bar or reducing the rear track with control arms are all possible solutions to the problem though, as is triming the rear fender liner, if autocross rules don't stand in the way.

 

was the rubbing at the rear or front? from what i've read on this, the concern at the front is the tire rubbing the strut, and at the rear is the tire rubbing the fender lip. with this offset i should be ok at the front strut. the wheels i am looking at are 6.5" wide.

 

I have 215/50r15s on +40 15x7s at stock height. I don't have any rubbing, but the insides of the rears seem quite close to the fenderwell linings. My unconfirmed suspicion is that the 225s would rub on a lowered car.
My 2 cents.
Best - Bodinski

 

The rubbing was at the rear and I did use a 1/16" spacer in front to keep the tire off the strut, with my 7.5" +43's, now that you mention it. With 6.5" +40 wheels you will have no problem in the front.

 

The M7 springs are low- about 1.2 to 1.3" drop for most MINIs.

Your current wheels: (let's compare using the Bridgestone potenza S-03)
205/50-16 with X-lyte 16x6.5" rims and +48mm offset.
This tire is perfect fit for 6.5" rim, sectional width of 8.4", tread width 7.6" outer diameter of 24.1"
For difference between sectional and tread width see-
http://www.tirerack.com/a.jsp?a=EZ3&url=/tires/tiretech/tirespecskey.jsp#sectionwidth

Proposed wheels:
Flik 15x6.5" rim +40mm offset
225/50-15 tire is a perfect fit for a 7" rim and is about a pound heavier.
Sectional width of 9.3", tread width 8.3" outer diameter of 23.9"
Due to 6.5" rim used the sectional width would be expected to be 0.2" less so about 9.1"

Given this above, I would recommend you give Alex@tirerack.com a call and ask. I think it is going to be very very close to rubbing but you might do ok if you are running enough rear negative camber to allow for a bit of clearance between the tire and inner rear fender well. My gut feeling is that it will fit.
Maybe some minor rubbing under load or with uneven road conditions.

 

minihune, thanks for the excelent post! lots of useful info. right now i have toyo proxes 4's and i am planning on getting the same. i looked up the specs on these toyos in the 225/50/15 size and the sectional width is 9.1" measured on a 7" rim. that will make it approx 8.9" on the fliks, so that gives me a little more room. the fliks are the same width as my stock 16s but will stick out 8mm more (40mm offset vs. 48mm). the tire will be 15mm wider, half of which is 7.5, or 8mm. so that is 16mm extra sticking out, or just over half an inch (0.62"). it's not as much as i thought, i feel like it may just fit!
still would like to here from personal experience if anyone else has done this... anyone?

 

sonichris,

While your calculations are fine, the tires themselves don't always measure up to what the specs predict. The difference between a 225mm and 205mm tire "may" in reality be less than expected (isn't it 20mm not 15mm or did you actually measure the difference in person?). The +40 wheel offset makes rubbing the inner wheel well risky. I have +42mm on 17x7" rims that rubbed with just H-sport springs and a 1" drop. If you can adjust rear camber to more negative like -1.8 degrees, that might help but first see how it fits first.

225/50-15 is not a common choice for replacement tires for most MINIs running 15" rims. They don't really fit well for a stock 15x5.5 rim which is too narrow for the 225/50. For those with 15x7" rims the 225/45-15 is more desireable for autocross and track use but has a small 23" outer tire diameter and isn't a good size for street tires. For street use the 205/55-15 tire is proportionally closer to stock, gives good enough performance, a smooth ride, and is available in a wide range of tires. You might get slightly lower mpg with a wide and heavy 225mm tire.

 

i got the tire specs from edge racing. the 205/50/16s i have now are 8.3", which when you convert to mm is actually 211mm, not 205. the 225/50/15s are 9.1" (on a 7" rim), which is 231mm. i then subtracted 0.2" for mounting them on a 6.5" rim and got 8.9", or 226mm.

so 226 - 211 = 15mm. of course these aren't exact, but close enough for specualtion. by the way, the weight difference is 20.5lbs vs. 21.2lbs, the 225s being only 0.7 pounds heavier. but combined with the 11.9lbs flik wheels, the combo would be 5.4lbs lighter than what i have now.

as far as why i am choosing this size... i am just examining three possibilities. one stipulation is that they all must be the same (or relatively close) diameter. (yes, these will be used on the street). i'm considering the flik apex2 in 16x7 +42mm flavor with the same tires i have now, which should be no problem, or the flik 15s with the 205/55/15s you mentioned, which again should be ok. but aside from the higher grip i could get from the 225s, i think it would look cool too, kinda like big fat gumball tires, real mean lookin'... just brainstorming. damn, i was 2 seconds away from ordering these too, and now i'm re-re-rethinking everything....

 

Are all of these measurements made from a spec sheet or from actual tire measurements?

As tires wear the outer tire diameter is reduced over time.
Even though tires ought to be roughly the sizes as you mentioned, each tire can be slightly wide or narrow than expected.

For example (from actual tire measurements) I have two sets of 205/50-15 tires mounted on the same stock 15x5.5" rims. When I stack four of them on their side my Kumho victoracers are about 32.2" tall while my Michelin Pilot Sport Cups are 31.0".
I have a set of unmounted 225/45-15 Avon Tech Ra tires that measure 36.75". 205/50-15 Kumho V710 tires on 15x7" rims measure 34.25"

As you can see the 225mm tires are quite a bit wider than 205 tires. Weights vary from tire to tire and the listed weight is from the manufacturer.

 

I'm running 225/50-15 Victoracers for track use on 15x7 Rota Slipstreams (40 or 38mm offset) and my car is lowered about 1" on H-Sport springs. I had a slight bit of rubbing in the rear when the tires were new (and unshaved) and when cornering -- it went away fairly quickly (after a session or two). So, without looking at all of the numbers you ran above, I'd say you may be able to get away with it -- and if it did rub it might only do it on heavy cornering, not routine street use.

I did ask Alex at TireRack about rubbing concerns before I purchased the 225/50 Victos and he said they would be fine. He was right.

 

I'm currrently running 225/50/15 Pilot Sport Cups on Kosei K1s ET4? on a non lowered Cooper S with Camber Plates front at -1.8 and lower arms rear. There seems to be pretty of room for me... Sort of close to some of the suspension components. Eyeballing this last time I had the wheels on the care it looked like with a 1" drop i should still be fine.. any more than this might start being close to rubbing.


T

 

Due to 23.9 inch OD

Alex

 

alex, so what you are saying is that since the diameter is slightly smaller, i should have a little more room before it rubs? in other words, where as now the rear wheels can actually tuck up into the rear fenders a bit, with the 225s the tire would hit the fender?

 

what if i used a 15x6.5 with +45mm offset? i found some rota slipstreams on their site that look identical to the fliks i want, and they are available in either +40 or +45.

so now looking back at my numbers i would only be sticking out 11mm more, or 0.43in, a little less that half an inch. now i have to see how much room i have between the front tire and strut. what would be the closest i could run and still be "safe"?