An ET 37 wheel or, say, an ET 42 wheel?

Wheels that protrude more appear (and maybe actually do) have a wider appearing stance, which I find more aggresive looking.

 

Assuming both wheels are the same width, the one with the lower positive offset will protrude more. In your case, the ET37 wheel will protrude more than the ET42 wheel.

 

Correct.

Stock MINI wheels with +48mm offset means the wheel sits farther into the wheel wells.

If you use the same sized rim width and reduce offset to say +37mm you have moved the outside edge of the rim farther to the outside of the car by 11mm or about 1/2".

If you get rims that are wider than stock and want them to be about the same position in the wheel wells then you will need to reduce offset.

Assuming stock suspension both +37 and +42mm offsets will work with a stock width wheel.

Once you lower your MINI then there is much less clearance and the +42mm offset will work better if you have stock width wheels.

Even with a lowered MINI it is possible to use the +37mm offset wheels if the wheel is wider than stock and you use tires that are less than stock tire diameter roughly 23" to 24" diameter. Rear negative%OYAfmber will also help with clearance.

 

Can you explain why a wider wheel with a lower offset will not rub as much as the same lower offset but narrow?

In my case I am looking at a 35 offset 16x7.5... I don't want to deal with any rubbing issues and never plan on lowering the car. I don't want to change any of the driveability characteristics just to get the wheel I want.

 

Lets compare your proposed wheel with the stock 16x6.5" wheel using the same non runflat 205/50-16 tire. MCS with stock suspension.

16x7.5" et +35mm

Although the rim is 1" wider than stock it is positioned essentially the same as stock due to less offset by 13mm. Since 1" is about 25mm for every 1" wider your wheel you can lessen offset by 1/2" or about 12mm to keep the wheel in the same position relative to it's stock position in the wheel well.

Try it on this wheel calculator and see how the picture looks.
http://www.wheelsmaster.com/rt_specs.jsp
Use the same 205/50-16 tire
Notice that the backspace is 143mm of 5.6" for both stock and your proposed wheel which means the position of the wheel is same as stock.
The proposed wheel and tire will be about 13mm farther out of the wheel well but still be fine.

I think you will be fine with the wheel you picked.

Now lets compare with 16x6.5" +35mm offset and same tire
Since the wheel is stock width and offset is reduced-
The tire now sits further towards the outside so wheel and tire are 13mm towards the outside of the MINI but now about 13mm less towards the inside of the wheel well- this creates no problems on the side facing inward. In this case the extra 13mm facing outward is not enough to case trouble since suspension is stock height and tire is smaller than stock 24.4".

 

Thanks for your very helpful, detailed response. The wheels I'm considering buying are 17" X 7" OZ Ultraleggeras which, as I'll bet you know, are ET 37. From what you said, I should be fine with those, since I plan to put stock-sized 205/45 X 17 summer tires on them.

With that tire size in mind, which tires would you recommend I consider for spirited city, country road and highway (but not track) driving?

And, if you know it, what's the ET on my OEM Mini crown spoke !7" X 7"ers?

 

Great information. I've always wondered about offsets.

Thanks

 

R104 Crown Spoke 17x7 wheels are +48mm offset like all other MINI 17" stock wheels.

The 17x7 +37mm offset wheels will fit MINIs with stock suspension fine.

For summer tires in 205/45-17

In Max Performance class-
Dunlop SP SportMaxx $128 each 240 treadwear 20 lbs
Toyo Proxes T1R $116 each 280 treadwear 20 lbs
and others

In Ultra High Performance class-
Michelin Pilot Exalto PE2 $124 special price 240 treadwear
BF Goodrich g-Force T/A KDW2 $120 each 300 treadwear (not as comfortable for daily street use)
Kumho Ecsta SPT $99 closeout 320 treadwear ($134 for runflat version)
BF Goodrich g-Force Sport $109 each 340 treadwear

For each list the top tire listed is worth considering, check them all out and talk to others in your area that might also have them.

 

So, to make sure I have this right, a zero offset would have the wheel hub surface, that contacts the car hub, centered in the rim. A + offset moves it towards the outside of the car and a - offset moves it in towards the center of the car. Right?

 

Right. The "deep dish" wheels you see on rear-wheel drive cars have large negative offsets.

I really wish the import world used "backspacing" instead of "offset". Both terms measure the same thing, but I think backspacing is easier to understand because the numbers are always positive.

 

Minihune:

I've been considering the Pilot Exalto PE2's but, now that you've suggested
them, I'll give some thought to the SP SportMaxx's, as well. I've read the survey results for each of them on Tirerack, which seems to give the Exalto's
a slight edge in comfort, and the SportMaxx's a slight edge in handling.

Which of those two tires do you believe would provide the best balance of handling performance and comfort for spirited driving on a combination of crappy city streets; smooth, curvy country roads and highways.

Thanks for your input.