Okay, after years of swapping winter 15's to summer 16's, I realized the heavy, factory 16's may not be the ideal wheel for the non-S? I was given a set of R81 15"X 5.5" rims and thought this may be a good test to try the R50 with lighter unsprung weight and a proper, smaller tire? Perhaps more torque with a smaller diameter?

Seems the factory 175 width is very limited finding a tire you can push a little. So tire science says to stay within +/-3% of original tire height. Where I'm struggling is, determining what the base size is to run the calc's. My car came with 195/55-16 tires which are factory spec for the "S".

I'm guessing basic Coopers are geared and calibrated for the 175/65-15's where the 195/55-16's were shipped on the car knowing the speed-o was a tad off? There is a .4" difference between the two making me crazy. The factory 15 being 24" and the 16 is 24.4". That really messes with the sizing calc's.

I'm looking for an H or V rating with the smallest size side wall. Going under sized such as, 185/60 or 195/55 is where side wall roll-over is minimized. I read the 5.5" rim is boarder-line for the 195 width so the 185/60 or 185/65 are basically the options. And of course V rating is not to be had in those sizes. So have a look at the calc results...

175/65-15 24” (stock 15 wheel)

185/60-15 23.7 -1.3% *
185/65-15 24.5 +2.1
195/55-15 23.4 -2.5
195/60-15 24.2 +0.8

195/55-16 24.4” (stock 16 wheel)

185/60-15 23.7 -2.9% *
185/65-15 24.5 +0.4
195/55-15 23.4 -4.1
195/60-15 24.2 -0.8

As seen above, the two factory sizes really change the percentage of difference. I'm favoring the 185/60-15 if the base size is 175/65-15. However, should the calcuation be based on the taller 195/55-16's, it becomes on the edge of 3% where the 185/65 is a better choice. I'm probably making this hard but thought it may be worthy to have subject matter experts jump in determining what the actual MINI wheel size is? Could it be 24" or the 24.4"?

 

I would say that it's not critical what size tire you put on the MINI as long as it has a tire diameter of roughly 24.0 to 24.4". There is always going to be a little speedo error with various wheels and tires used for the MINI, it's close enough for street use.

More important is what are your requirements for tires? Not all tires will come in sizes that will work with OEM 15" wheels. A base cooper is still plenty capable so no budget basic tire is going to be up to the task.

You're in Washington state so how cold does it get? Under 40 degrees and some snow to drive in the winter? If so then you need All Season tires or need a set of winter wheels and snow tires for deep snow.

Summer tires aren't going to work with temperatures under 40 degrees and the best performance tires don't usually come in 15" sizes.

All Season tires come in two categories well suited for the MINI. Ultra High Performance All Season and Grand Touring All Season.

UHP All Season- this is a blend of good handling and performance with longer treadlife and some ride comfort and lower noise for daily driving. Good for dry or wet and tolerates a little snow and some cold.

Kumho Ecsta 4X II
205/55-15 will fit 15x5.5" (range is 5.5-7.5" wide rim), tire diam. 23.9", V speed rated, $64.91 each, 420 treadwear

Grand Touring All Season trades off some handling and performance for more ride comfort, low noise, better suited for commuting and has long treadlife. It's still capable enough for good response for the MINI but it's not as responsive.

There are many tires in this class for 195/60-15:
https://www.tirerack.com/tires/surve...=true&filter=y
Prices range from $53 to $125 each

A good value tire that is decent would be -
General Altimax RT 43 $69.70 each, fits 5-7" wide rims, tire diam. 24.2", H speed rated, 600 treadwear.
Tirerack review-
https://www.tirerack.com/tires/tests...y.jsp?ttid=227

Personally I use Grandtouring All Season tires with 15" OEM wheels for daily driving on my race modded Cooper S and it works fine. When I run 17" wheels and Extreme Summer tires the ride quality is very harsh and jarring. I have Bridgestone Ecopia 422.

If you have winter tires and are looking more for Summer tires then-

In Ultra High Performance Summer tires for 205/55-15
Kumho Ecsta PS 31 $89.85 each, V speed rated, 400 treadwear, will fit OEM 15"wheel
Tirerack test results-
https://www.tirerack.com/tires/tests...y.jsp?ttid=217
More of a commuter tire, gives up on handling and performance vs other UHP Summer tires. Dunlop Direzza DZ102 is better but costs more.

 

For OEM 175/65-15 there is a possible choice-

High Performance All Season
Sumitomo HTR A/S P02
$54.50 each, fits rims 5-6" wide, H speed rated, 600 treadwear, tire diam. 24"

Tirerack test results-
https://www.tirerack.com/tires/tests...y.jsp?ttid=221
Favors handling over ride comfort/noise

 

Just a note- I've used OEM 15" wheels for many uses except driving in snow with my MINI over the years.

175/65-15 doesn't give much tire selection but it works and is very light weight and costs less. It has less rubber on the road so better mpg and rolling resistance. Not as good for outright performance. Good commuter tire.

195/50, 195/55 and 205/50-15 will fit OEM wheels but has small tire diameter and lower ride height and road clearance. It works and gives more tire selection for track or autocross if looking at 205/50-15 but still can fit OEM wheels.

 

Thanks for responding MH! I remember your interior avatar with the cool exotic wood (Koa?). I was drooling over it back in 2004 when I bought this car new. Yikes!

I think you're right averaging the measurement/calc to 24"-24.4". I found 185/65's (Mich.) actual measurement at 24.4" unlike others where 24.5 the most common. Even the tire OEM's vary the diameter a bit it seems. Settled for 175/65-15 or 24" as the baseline. The bigger sizes (exceeding 24) drops RPM in 5th making for better mileage but less torque. Mileage and speed-O accuracy are not a concern. Coming from 205/50-16 Toyo Proxes4 for handling example to come close to.

After reading your info., I explored the 175's but again and spotted a "Continental Premium Contact 2". It had Zero reviews on the Rack. I skipped it before as - ho, hum, another Conti. Turns out it's a summer UP, grand touring puppy. Rated H speed, AA traction, A heat. I found great reviews for it on UK tyre sites. They have them in many sizes in Europe but just the MINI, Skinny (175) is available in the US. They stated these shipped on new MINI's? Pretty sure they didn't as they're a fast wearing (280) compound for canyon carving and are instant death on snow. Not sure the factory ever shipped them here, maybe the UK? I recall factory Conti - ProContact or TrueContact, (All-Seasons) models on 'em not these buggers.

Anyway, these look dandy fine to shred as my Wife runs Blizzak's (on separate rims) in the cold. They have no mileage warr., the Britt's love pushing them as Ricky Racer tyres but seem very good with wet breaking and grip. Hoo Hoo!! (My Wife's a lead foot). Gotta give 'em a go for the lighter may be better test? I'll put up a post about the transition and highlight this somewhat secret bugger. Hopefully it will be a sticky treat to apply some G's to.

http://www.continentaltire.com/produ...17565r15-84h/?

Thanks for the input!

 

Continental makes several tire models that come in 175/65-15 and Premium Contact 2 is not OEM for the MINI but it is somewhat close.

Generally most times you will find All Season tires as the default street tire to come with most basic models of any car, it's low cost and works no matter the weather except for deep snow.

I have used 2 to 3 sets of OEM MINI Continental 175/65-15 tires for street use and they work fine but aren't great in anything particular however you may not require more for daily use.

Continental ContiProContact is a Grand Touring All Season tire that comes in 175/65-15
$86.50 each, 400 treadwear, 16 lbs, star MINI model, Eco focus.
Tirerack test results-
https://www.tirerack.com/tires/tests...y.jsp?ttid=138
Before you buy/decide check out these-

Other good choices for GTAS tires in 175/65-15:
Vredestein Quatrac 5 $76.62 each, 400 treadwear, 14 lbs, H speed rated
General AltiMax RT-43 $70 each, 600 treadwear, 15 lbs, H speed rated

 

Thanks for bonus tips. The Altimax and Quatrac are indeed options I reviewed. But I ordered the Conti Premium Contact 2's. Mainly from the UK reviews and popularity.

Taking the Toyo Proxes 4's with 16's off and going with the Imola 15"s and Conti's. Saves 14 lbs. a corner, 56 lbs. total. Should be noticeable but hopefully not too far from how the Proxes performed? Any 4-Season tire would be a compromise for the test. Will put up a review when they're broken it a bit.