OK, 205/45/17 is the 17 inch stock tire. Obviously fits fine.

215/45/17's are a reasonable choice. Only .8% larger radius, and a tad more meat.

Has anyone run 215/50/17's ? 4.3% larger, so it would almost fix the speedo error, and would be darn close on the odometer.

Getting greedy, 225/45/17's are 2.8% larger. Anyone run them? That's a full inch and a quarter fatter, so is it pushing the clearance?

(OEM s-lites) I am not concerned with it being a tad slower. Plenty of power as it is.

 

I have run the 215/45/r17 and I don't think I would go any fatter on the side wall. You'll start getting side wall roll which isn't good. Any reason you want that fat?

 

I'm running 235/40R-17's now. Autocrossed it last weekend without any trouble and checking the tires over, they weren't rolling too much - never made it out over the edge of the tread patter. Only very slight rubbing up front when making full (to the locks) turns. I'm also lowered (about 1.2") so that reduces my clearance.

Good luck!
Craig

 

Not really considering the 225's but always good to know the bounds. I think I would run at least an 8 inch rim for that anyway. And it is true, too much sticky rubber the car will dart all over the place on our "lovely" roads. Not enough rim and the sidewall just gets the wigglies.

So the 215's are probably correct for spirited street use. I really want to know if the 215-50-17's on stock offset clear. I ran RE 960 205's on my RSX and it was about the same weight. Not quite enough. For "normal" people, the 205-50-17 would be a rational choice. But then I never claimed to be quite normal.

All this is preferenced on the factory offset wheels. As soon as one goes aftermarket, offset is all over the place and it is a one by one guess. It would be great if there was a sticky with tested combination's that included wheel spec.

I am stock ride height. Unless I need to change springs to get the balance correct, I may not drop it. A quick look says the rear suspension stays on the negative camber side even at stock. ( not so on the last 15years of Honda's). I am not looking for absolute speed as I don't "FAT" or autocross any more. Just going for the thrill of driving a car that is balanced and does exactly what you expect. The Mini is a good base, just not quite there from the factory.

Sounds like Craig found the limit. Don't know what wheel or offset he mounted on. Bet it is no fun in the rain!

 

While I am at it, guess I need to find lug bolts suitable for being exposed. Saw these, kind of cute if you had black wheels.
http://www.radusadirect.com/product/...-for-MINI.html

 

TVR,
It's actually very well mannered in the rain and, believe it or not, even in snow. I'm running Kumho Ecsta ASX tires and they are great all-season tires. We had rain most of last week and we've got 1-2 inches coming over the next day or so and I'll be driving it every day. During "Snowmageddon I & 2", I was able to get out and about. At one point, I even had to do my own plowing to get through an intersection and the drift that I moved had my license plate imprint in it!

I'm running Rota Torque wheels in 17x7.5 with a +45 offset. I was a little worried about that narrow rim width with the tires but they mounted up nicely and with no hassle. One thing that I noticed right away was the change in the ride. My previous tires (225/50R-17) and the lowered stance gave a very harsh/jarring ride. Now, it's much more comfortable. We figure it's because the sidewalls are slightly angled so they deflect/absorb some of the jolt. They did great on the autocross course last weekend too.

I do get some very gentle tramlining on some roads but it's not a scary thing and and it only happens when I'm going slower. When I'm at speed, I don't notice it.

I agree though, it would be good to have a spreadsheet or something that listed the specifics (which MINI, wheel diameter & offset, tire size and impressions of fit). Not a discussion of one tire over another or anything. As Joe Friday said, Just the facts M'am.

Craig

 

Think you can go up to 225 on the stock 7" wide wheels with no problems from what I've read here. For 235's you need a wider wheel.

 

Here's my 2 cents on this. My old '02 MCS came with 199/55/R16s from the factory. It was a dealer demo and was upgraded to 205/45/R17s. When I compared the speedometer against my GPS, it was off by 7%! When it said 50 MPH, I was only doing 46 MPH. 75 MPH on speedo = 69 MPH actual. I also verified this against a radar when I went by (not at 75 MPH, though).

Interestingly my current '06 MCS came with 205/45/R17s from the factory. Guess what... it's also off by 7%! And, if you have not figured it out by now, that means the 50,000 mile mark will occur at only 46,500 actual miles. I've thought about complaining myself. However, as long as nothing happens during that mileage frame (up to 53,500), I'm gonna leave it alone.

Best advice I can give is to compare your speedo against a GPS or radar and go from there. One alternative size is 205/40/R17. Not sure what to select for 18" or 19" rims.

 

I think mileage is typically more or less accurate with factory tires and the speedo reads higher due to european laws, or so I've heard.

 

Stock 195-55-16 tires:
I read 23 at 20 ( radar sign) on the digital gauge.
36 at 30, radar sign. The analog gauge reads another MPH higher.
Measured odometer on mile post markers, over 10 miles, off by 5%.
Driving less that 65 indicated in a 55 really ticks off drivers, so I am guessing the error is not a fixed 2 MPH as BMW has suggested. I do not have a GPS. Note the spec for GPS is still about plus or minus 5% so it may not be that good an indicator. When I get a new battery for my stopwatch, I will do a long highway run to find the error at 65.

Speedo falls within the 10% + 2 MPH legal limit from the 1920's US laws that were never updated. BMW is totally arrogant about it. I saw their official policy. All the line about tire varriation is total BS when you consider there are between 5 and 7 sensors on the car that talk to the ECU which talks to the speedo. The largest tire I mentioned is only 4.3% larger, so even the 215-50-17 would not fully correct my speedo.

So, yes, our warranty expires about 5 to 10K miles less than what is real when based on the gauges. I consider that fraud. It is very clear BMW as a corporation does not care at all about it's customers. Some dealers may have a better business attitude, but the parent company has made their view clear. To be fair, they treat 7-series customers the same.

 

if you have not done the math, based on revolutions per mile specs from Bridgstone, referenced to the 195-55-16 stock size.

205-55-16 is 1.8% larger
205-45-17 is -.3%, so you would not see a difference
205-50-17 + 2.8%
215-45-17 + .8%
215-50-17 a full 4.3% larger.

Note that revolutions per mile does vary by a small amount from tire to tire across brands, and the tread depth will vary by about .2% over the life. Inflation can vary a lot depending on the belt design. The above calculations are based on single vendor specs, so conditions are even. It is a difficult apples to onions comparison.

 

I've read in other posts on this subject that the speedo display is faster than actual speed (mine is about 3% off) but the odometer is actually correct. There are a couple of measured miles on I-95 but I've never checked my odometer against them.

Not too sure about the accuracy rate on the GPS either. I've got one that I use on my bicycle and it actually has two speed inputs. The first is of course the GPS and the other is a magnetic sensor and counts the wheel revolutions. It's calibrated to the actual wheel size and I've got it measured down to the 1/16th of an inch for calibration. When I compare the readings, they are within 1% - I'm a little OCD about my training log...

I'll take it out on my next highway trip and see how accurate the odometer is.

Craig

 

Yeah, I was really tired yesterday and ranted uncontrollably. I did not even go back and check to see that 195/55/R16s and 205/45/R17s are about the same size. I am still peeved about the % it's off regardless of the size, though. Perhaps this is why the dealerships do occasionally offer a goodwill exchange. I did get one with my old '02 MCS.

As for GPS accuracy, if you go into the mode where you view the satellites the unit syncs up with, you will see a variable that indicates as such. I have a Mio C310, and the parameter starts out at about 1.30 when it first gets three or more satellites into view (the minimum needed to pinpoint your location). After communicating for awhile, the figure will hover between .90 and 1.00. So I consider the GPS to be fairly accurate in determing speed. I would believe it more than a speedo or a radar unit.