2nd Gen R56 Cooper S Most liked posts in thread: Stock Tire and Wheel

16" wheel, not sure of the tire size.

Mark

 

195/55-16 is what was on mine on delivery, but there are optional 17 and 18's available from the factory as OEM sizes

 

Mine with the Sport Pack was 17" 205/45/17

 

I have a "justa" just bought a set of wheels and tires off a fellow Mini owner I went from stock 15"s to 205/50/17's fit perfect never lowered it. If I had I don't know that they would of fit. The biggest difference I've noticed over the last week is my gas milage has dropped. I was average about 39, now I'm getting 34 mpg. But I definately like the profile (look).

 

PICTURES, PICTURES, PICTURES.......

or

:useless

 

No, stock MCS will have a "sportier" suspension than a stock Justa (without the sport upgrade). I think this mostly boils down to swaybar diameter differences.

 

How are you calculating the new MPG? Keep in mind that with the 205/50/17, your odometer will now be incorrect...so calculating your mileage off that will no longer be accurate.

 

Rally Stance, actually thats the strange part. When I had the origionals 175/55/15 my mph was off 4 miles per hour, so it showed me going faster than I actually was. Now with the 205/50/17 its only two miles per hour. Wouldn't it of been the opposite? As for pictures I will be taken pictures tonight. Its just a perfect fit I think.

 

A nerd writes:

A 205/50/17 is 4.6% bigger diameter than a 175/65/15, so that's how much difference there should be in speed and distance. So your 39mpg on 15s would become 37.3 on the 17s just because of the change in diameter.

The rest of the difference will be from the increased aero drag of the wider tires - drag from tires is quite a significant contribution to total aero drag.

I recently switched from 175/65/15 to 195/55/16 and have seen about a 2mpg drop - and about half that drop is because the 16" tires are bigger diameter.

Andrew

 

Andrew....... I have a question......
In your first example.... Since the circumference increased going to the 17" size, one would assume if there is no slippage in the transmission (a manual), wouldn't for every rotation of the crank, the MINI should roll farther. Wouldn't that in itself improve the miles per gallon, not reduce it?

I agree that increased tire profile width and height would increase drag, but I'm not sure I follow your rational on the diameter increase reducing the speed and distance.

 

We're getting to technical for me. That was very telling Andrew, thank you. As for the 3% beyond safe increase. I really don't understand that. Theres lot of Mini's out there with 205/17's on them. I have never heard that before. Besides I think the origional tires should of been 185's not 175's there to small. In the winter I will switch back to my 185/50/15 Nokians, OMG for me thats in October. Winter is around the corner.

 

So I just did the caculator (tire) thing from jbewly, its brake failure I have to worry about? Thats real comforting, since I cross over two mountain passes over 11,000 ft. each day.

 

It's confusing, innit?

If you drive a 39-mile road on 15s and the car uses one gallon, that's 39mpg.

Now switch to the bigger 17s and drive exactly the same road. Because the tires are bigger, they had to make slightly fewer revolutions to cover the 39 miles and so the odometer will say that the car has only done 37.3 miles. If we assume for the moment that the drag is the same for both tires, the car will still have used the same one gallon. So it will look like the fuel economy has got worse, but actually it hasn't.

Since in this example the economy had gone to 34mpg, it is about 3mpg worse real economy plus 2mpg worse from the change in wheel diameter, giving the 5mpg total. But only about 3mpg of that change is for real.

Is that as clear as mud?

Andrew

 

Maybe.........

Ah, but I'm not using the odometer, because I know it's off with the 17" wheel. The length of the 39 miles hasn't changed, it's still 39 miles, but with the longer rolling distance for each tire revolution, I would use less actual gas than perceived gas for the actual distance than the perceived distance.

However I would be using US gallons not imperial gallons (I get 50 to your 41.63). I would be driving my 39 miles to your 62.76 kilometers (So I would get beer sooner:beer). I would be driving from east to west, so the earth's rotation would be assisting my MPG. I would be buying my gas with dollars not euros (so I will have more left over for beer:beer).

Yeah........ it's clear now:lol::lol::lol:

 

jbewly, you hit the nail on the head I usually got 112 to 114 on the gas ticks on the first one the other day I got 98 miles. That 14 to 16 miles difference. I'm still happy with the overall milage, I'm more concerned about the brake failure part now. Does that mean I would be changing brakes more often or do I need to go to a bigger brake system?

 

Riddle me this, all things being equal, will an 18" wheel and 17" wheel weight the same, assuming same tire and stock profile on each tire? The 18" rim should weigh more, but then the tire on that rim should weigh less. Just curious :rolleyes5: