tires instead of the standard 15 tires. After talking with a friend he told me to be careful because when you switch to a larger tire size that it creates higher mileage and throws off your speedometer. He said I may have to get it calibrated. Is this true? Would one inch make a difference? My mechanic said that 15 tires were made mostly for MINIS. That they are hard to come by. Has anyone upped the tire size and notice a difference? Thanks.

 

he's saying go to 16s because the OEM 15 tires are hard to come by? Odd logic....

All the OEM tire wheel combos have the same rolling diameter within a percent or two. Wheel diameter doesn't determin rolling diameter, it's the tire that does that. This is the rolling diameter of lots of the stock Mini tires...

175/65 R 15 24.4” Continental ContiTouringContact
195/55 R 16 24.4” Dunlop SP Sport 3000
195/55 R 16 24.6” Goodyear NCT
205/45 R 17 24.2” Dunlop SP Sport 9000
205/45 R 17 24.3” Pirelli Eufori

You can see they're about the same 15" to 17" wheels. Also, there's no reason you have to stay with OEM tires, and 15" tires are less expensive than the same 16" tire....

Hope this helps....

Matt

 

You can also run 195/60-15 or 205/55-15 tires on your stock 15" wheels.

 

You may find that tires on 16" rims ride just a bit harsher that the 15", but benefit is the handling will be a bit better. There's also a greater variety of 16" tires to be had. I went with a 205 50 R16 three season tire when I bought my 16 inch rims and I keep my original 15" rims and tires for winter driving.

 

I have both 15 and 16 inch wheels. I use the 15 inch wheels for the winter and the 16 inch wheels for the summer. I have 175/65-15 all seasons which, probably because they are narrow, work find in any snow my front bumper clears. I've still got stock Dunlop run-carps on the summer wheels but am trying to decide what to put on the rims before its time next April. I'm not at all disturbed by different speedometer outcomes. I just figure out the error and adjust accordingly.
The lighter the tire and wheel the better the fuel economy. Smaller wheels tend to result in a lighter setup. They also tend to result in a less proficent handling unless you go to wide small wheels with wide tires (which I suspect would tend to increase the weight).
As a side note I'm discovering a lack of choices for my son's 87 Honda Accord. It too suffers from a tire size mainly made for a specific brand/model. I wouldn't doubt that the narrow 15 inche tires for the MINI may be hard to find someday.

Maybe.

 

There are plenty of 15" tires available that will fit the stock 15" wheels, in addition to the 175/65 tires, you can also fit 185/60, 195/60, and 205/55, all of which are within 1% of the stock diameter and won't throw off the speedometer by a noticeable amount (it would theoretically be off by only 1 mph when travelling 100 mph).

As others have mentioned, your friend is wrong about upsizing to 16" wheels. It can be done without changing tire diameter, but instead of paying $300 and up for a set of 15" tires, you'd likely have to pay $800-1000 (or more) for a set of 16" wheels and tires that will be heavier (unless you spend a lot more money for lighter weight wheels) that will make the car ride more harshly and will slow the car down because of the increased weight. The slight increase in handling isn't worth it IMHO.

-Keith

 

I have stock 16" wheels with all season runflats that I am going to keep for winter and get a set of 15" Konig Rewinds with UHP summer tires. Most people look at me a little wierd for going to a smaller wheel, but I like the look of 15s on the MINI.