I just sold my R50 and am now looking at a 2014 Mini One (F56?), manual, 1600cc, 98hp.

My question: The current owner got rid of the standard 15" tires and put on 17" and I was wondering what effect this has on the car - driving, handling, mpg, wear and tear, replacement costs, etc...

Thanks.

 

I bought a 2011 Mini new that had 15 inch all weather tires on it. I wanted to upgrade so I found a set of used 17 inch Mini lites. The car looked great but the larger and heavier tire/wheel combination had a real negative effect on the cars acceleration and gas mileage. My car is an automatic Non-s , and with the larger wheels and increase weight it felt like I was carrying a couple of people in the back seat. It had to down shift more on hills and was not as responsive. My wife it noticed it. I sold the wheels and found a set of 16 inch Rotas and put them on the car. The 16 inch is a good compromise between good looks and not reducing performance. Bottom line is the weight of the tire and rim you put on your car. My 17inch wheel and tires weight 44 pounds each verses about 30 pounds each for the 16 inch. Be sure when you compare tires and rims you get the lightest combination you can. Also, if your car is an manual or an S then you may not notice the decreased performance as much as I did.

 

What soda said.

 

I dont know if the 56 extra pounds will make as dramatic a difference as the previous poster mentioned, but the change to the final drive ratio will make the car feel more sluggish.
I know I am new to MINIs (dont even own one yet) but I am no stranger to cars and trucks and have some experience with changing wheels, tires, and gear ratios on 4x4s and the effects on performance.

 

OEM 175/65-15 to OEM 205/45-17 is less than a 2 percent taller increase in drive ratio.

 

First, I am going to assume that they went with the "+2" strategy, where the wheel size is 2" larger, but the overall diameter of the tires is close to the same. That is a popular way to go, BTW, because it keeps the stock gearing.

Most of the time, the +2 setup will be heavier than the stock setup. The weight will make the handling a little worse, the ride a little worse, and put a little more stress and strain on things. Not all larger wheel/tire combos will be heavier than the stock setup, though. You would have to check.

The shorter sidewalls of the +2 setup will give you better transient response from the wheels. When you turn the steering wheel, the car should react more quickly. You will also get more feedback from the contact patches, so you should be able to feel what is going on down there a little better. Finally, the reduced compliance usually (but not always!) means that the tire grips better going around corners. However, the short sidewalls transmit more bumps and harshness to the rest of the car. This reduces ride comfort, and can put more wear on suspension bushings and such. The rims will also have less protection from potholes with short sidewalls.

Larger wheels usually cost more than smaller ones. So if you bend a rim beyond repair, you'll have to pay more to replace a large one than a small one. And tires for larger rims almost always cost more than those for smaller ones. But the selection for 17"+ wheels tends to be wider than that for 15s, especially if you are looking for super-high-performance type tires.

Differences from tire type to tire type, and wheel to wheel, can be larger than the effects above. You can probably come up with a +2 setup that handles worse, gives better comfort, has less grip, and so on, than the originals do. But those are general tendencies.

 

There's no difference in final drive ratio because the overall wheel/tire combination has the same diameter. With smaller wheels you get higher profile tires.

The increase is all in unsprung weight, which makes a huge difference in ride, handling and acceleration. The ride quality is also worsened by the shorter, firmer sidewalls of the lower profile tires on the larger-diameter wheels.

I started to write up an explanation of why unsprung weight has a much more dramatic effect than the same weight added elsewhere on the car, but did a quick search and found that Wikipedia has a great article on it that saves me the trouble.

 

This is what I was referring too, its the unsprung weight that gets you. Thats why people who race cars want the lightest tire and rim combination they can get. When you buy tires you can check the weight of the tire, just like with the rims. Take my word for it from experience, it makes a big difference in acceleration and ride quality

 

I forgot one other thing. when you change the tire ratio ( say from a 60 aspect to a 50 aspect - narrower side wall ) it changes the tire's contact pattern. The contact point will be wider due to wider rubber on the road but shorter contact point. You are not increasing the total contact on the road just the pattern of the contact.

 

Thanks for all your help. Too bad that I went to look at the car and the owner had, IMHO, ruined it. Changed all the trim to S for some reason. So the car looked (slmost) like an S but obviously wasn't.