Just want to make sure I understand this:

- A lower offset moves the wheel inboard (closer to the center of the vehicle).
- A higher offset moves the wheel outboard (further to the outside of the vehicle).

Is that correct?

Can't an offset be calculated that would provide the most space in the wheel well?

 

it's the OPPOSITE. Smaller offset moves wheel OUTBOARD, whereas larger offset moves it INBOARD. (i.e. ET20 farther outboard than ET40).

M

 

I am so confused.

Oh, now I understand - the offset is the measurement from the hub interface to the center line of the wheel, right? So making that number smaller would make the wheel stick out more from the hub.

So, would an offset of 50 or 45 or 40 be better for fitting tires into the wheel well?

 

The higher the number the further it sticks under the car.

And the lower the number the further it sticks out
IMO the lower number the better it looks since the wheel is not tucked underneath the car so you can't see it. +38 - +40 puts the wheel right along the edge of the fender.. Also rember we are talking Milimeters so it is a very small diff between most offsets.

 

I understand, that but I am looking for the best fit (i.e. - largest tires that fit without rubbing). Looks are secondary to that goal, but I believe they go hand-in-hand with that goal in many senses. Wide tires look good!

 

so can you give us an example of what you are looking for in terms of rim and tire size and for which MINI? MC or MCS?
15, 16, 17" or larger rims?
Also note that the width of the rim plays a role that interacts with wheel offset since the wider rim must still fit in the wheel well and the wider rim also influences the width of the tire once mounted.

A 205mm tire mounted on a 5.5" wide rim would be narrow compared to the same tire on a 7" rim.

Generally 225mm tires are at about the limit in width that will fit into a MINI wheel well.
With stock suspension you will have a little more headroom and play but with a lowered MINI you are going to be very close to rubbing when wheel offset is about +42mm. +45mm to +50mm tends to be OK.

Common solutions using wide tires:
15x7" rim with 205/55-15 or 225/50-15 tire
16x7" rim with 215/45-16 tire
17x7" rim with 215/45-17 or 215/40-17 tire (225/45-17 likely to rub)
18x7.5" rim with 215/35-18 tire

You have to watch to see that the outer tire diameter doesn't creep up too high beyond the stock tire size given any tire of roughly 225mm.

 

This is for an MCS.

I'm looking at 16" rims, probably in 16x7. I was looking at 215/50-16 tires as they're very close to stock diameter/circumference. I was also looking at 225/45-16 tires, though I'm not sure the difference between 215 and 225 is worth the extra cost and weight.

Maybe I should go for something like the Rota Slipstream? 16x7 wheel, +45mm offset available.

I haven't seen many wheels (if any) available with over 45mm offset. Are there any? Also, how large is too large on the offset?

 

+45mm offset is about the most an aftermarket wheelmaker will use because it will only fit a few cars if offset is greater. MINIs will fit up to about +50mm offset depending on suspension upgrades.

Rota Slipstream is fine.

215/50-16 fits rims from 6 to 7.5" wide and has outer tire diameter of 24.5" (avon M500)
225/45-16 fits rims from 7 to 8.5" wide and has outer tire diameter of 23.9" weighs about one pound more and offers better cornering but more rolling resistance. Bridgestone Potenza S-03 comes in this size but is expensive.

The Avon Tech M500 in 215/50-16 would be a comfortable affordable street tire of stock size. The 225/45-16 tire will be harsher riding and might not get as good mpg if you do lots of commuting or street driving.

 

Do you think the 215/50s would rub significantly with a +45 offset 16x7 wheel and upgraded springs (approx 1" lower)?

 

The Volk ce28n is available in several offsets and widths with a 4x100 bolt pattern. I got +42 for my 16x8's and it's a very close fit but if you went with a 16x7 the +49 should work fine and help keep tall tires away from the fenders. I think they should offer that offset in the 17's too but they don't.

 

Still not sure that my stone-age mind is completely comprehending, so I'll ask a specific question.

I've got a 2005 MCS coming in a week or two. The JCW suspension will be installed when I pick it up, which reportedly lowers the car by a little less than 1/2". Also coming is a set of 5zigen 17x7 wheels (with +42 offset) with 205/45/17 Proxes 4 tires.

Should I expect any fit problems? When I ordered the wheels and tires, I thought I was staying right in the middle of the workable range. Am I right or wrong?

 

You are fine. Your suspension drop is minimal and your tire is stock sized.
Enjoy.

No, I think you will be OK most likely, Just keep your tire pressures correct.
There is slight variation with every MINI so an expected 1" drop like with H-sport springs is not always exactly 1". If anything there could be very slight rubbing in the rear with your MINI loaded with four people and if you buy tires that have a square shoulder like the Yokohama AVS ES100(but doesn't come in the 215/50-16 size).

The Avon M500 should work for a street tire and not rub. The shoulder is more rounded. Talk to Alex@tirerack.com to check for fitment issues.

 

Minihune, With what appears to be a great deal of knowledge regarding MINI wheels and tires I have a question for you. I have a '05 MCS (17" rims)with (of course) runflats. The spare tire I have in the boot, is it smaller in diameter to the tires on the road? I can not think that it is just because of the fact you can use the "donut" tire up to a speed of 50MPH (?). That being said, it I choose to replace the runflats with let's say Michelin Pilot Sport (215/45-17) on ASA AR1 wheels (17 X 7) would I have to replace the donut tire with a Civic "donut" tire? and would that Civic tire fit in the spare tire well in the boot? Thanks F

 

The '05 MCS comes with a spacesaver spare

 

DRAT!

 

Perhaps my previous post was confusing ...

Does the '05 MCS come with a spacesaver spare?

 

DRAT again, Yes the '05 MCS has a space saver spare And, as shown in the manual, it is cracked down from the inside the boot. What kind a dang deal is that. This the reason other threads have talked about carrying a "normal" spare lashed down in the boot. I guess I can still use a Civic or a Miata wheel and tire. F

 

My '05 MCS didn't come with a spare.

 

My MCS didn't come with a spare - there's a battery back there! (hey, that rhymes). I think you get the same owner's manual whether it's an MCS or regular Cooper, so if you're just going by what's in the manual - you can't always believe everything you read!

 

No spare you say. Must be the reason they give you run-flats. F

 

You are correct, sir.

 

If you have an MC then you have a small spare in the boot area and you can use this in case of a flat no matter what sized stock wheels you have and for most aftermarket wheels as well. Don't no any performance driving when using the spare! It is true that the compact spare outer tire diameter may not match the other tires but this is for emergency use.

You don't need the civic spare tire. However if you have the MCS of any year you do not get the compact spare tire but certainly you can pick one up and put it into the boot area- it won't fit in the MC under boot area because of the MCS battery location in the boot.

 

I have a '05 MCS and am planning on purchasing SSR Comps in 16x7.5 with 42mm offset. (I want silver wheels, and 16x7 is only available in anthracite.)

I am also planning on mounting 205/50/16 Toyo Proxes T1R's.

The suspension is stock, and will remain so as I autocross.

My concern is that with 7.5 width and only 42 mm offset, I might encounter some clearance issues. I think it will work fine, but would appreciate some feedback.

Thanks in advance.

 

Since suspension for you is stock you are "safe". (As Ryan Seacrest would say each week on American Idol)

205/50-16 will fit 5.5" to 7.5" wide rims and outer tire diameter is 24.1" which is slightly smaller than stock for more clearance.
For stock suspension you can run wheel offsets of roughly +38mm to +48mm. +42mm should not be a problem even with a 7.5" wide rim.

As a final check you can discuss fitment with Alex@tirerack.com since you are interested in SSR comps in silver which he carries.