It's about time to take my winter tires off and put the summers back on. I'm not putting the horrendous summers I had on and am 100% going to buy Michelin Pilot SS.

As you might imagine they come in 215/45/17 and 205/45/17.

I've read pretty much all the threads on the subject of these two sizes yet still don't have the exact answer I'm looking for. I know the 215 will give more protection, fill in the arches, and ride a little smoother. However, the 205 is what the car came with so it should be enough of the above.

My primary concern, when why I drive a mini, is the driving excitement. To me, a tremendous amount of that comes from a great road feel. The 215's seem like the better bet for other reasons, not to mention cheaper, but will I get a lot less road feel than the 205s? On many high performance cars you'll see the tires almost look smaller than the rims. I've spoken with chassis engineers and they say they do this do give you the most control and best feel.

Has anyone tried 205 vs 215 of the same tire? What are your thoughts?

Now for something a little crazy, can I go 205 in the front and 215 in the rear? It'll give me the nice stance out of the rear and very slightly lift the rear of the car up. The percent diameter differences are very small. 24.3 vs 24.7. Would this send the computer into a tizzy?

Thank you!

Best,
Gene

 

Not a good idea IMO running 2 sizes as you won't be able to rotate the tires then. As for the ride differences, that is dependent on the tire you chose. I have never run the Michelin's, but I can not imagine that small a difference making a huge difference that you would be able to tell. Also as you noted there is a very small difference in diameter, it does nothing to the computer. Your speedo will be a little more accurate though.

 

Thank you. My computer concern was not running a different diameter but running two sets of different diameters. The rears would roll slightly less often than the fronts. Once this amount is enough the computer would think there's an issue and apply traction control. I'm just curious as to the tolerance of the computer. As far as rotating tires I'm willing not to do that if the 215 and 205 are the best solution. It was a far fetched question. My main issue is still overall 215 vs 205 in the feel department. I drive my car at the limits and it will make a difference, I'm just wondering how much of a difference.

 

I will be running 215/40/17 front and 205/40/17 rear come summertime. Some autocrossers prefer this setup, I have never heard about problems associated with it.

 

Since you are using the same tire but in different sizes there will be small differences between the two.

If you want the very best handling then choose-
205/45-17 but they are more expensive at about $181 vs $154 each for 215/45-17.
To make handling the most predictable you should use the same size tire on all four wheels. Adding tire width to the rears (not your drive wheels) just adds weight and a higher rolling resistance (drag). I don't think there is that much rake difference to make it worth the effort given the additional 0.4".

As for Creeve's post-
205/40-17 and 215/40-17 aren't commonly available for a single tire model, the exception I found was Yokohama S.Drive (UHP summer tire).
While it can be used with 215/40 up front and 205/40-17 in back it will look a little more aggresive in the front depending on which wheel offset is used.
The tire width difference of only 10mm is minimal. Tire diameter is 0.3" taller and 2 lbs more with the 215/40 tire size.

In general the car will look more balanced with all four tires being the same size. However the difference is small.

I have run 225 tires in front and 205 tires in the rear on 15x8" front and 15x7" rear for autocross. It was OK, had a little more grip and a little less understeer in corners.

 

Thank you! This is what I was looking for. I guess, since my main concern is handling and road feel I should pull the trigger on a full set of 205's.

Best,
Gene