[Alan l.]

Since this will be a popular tire choice for the F10 I figure this will benefit others when they search on this topic and save them some headache.

Here is the deal with the Michelin PSS in "Ferrari K1" spec compared to the normal spec tire.

1) The Ferrari "K1" spec tires ARE different compared to the normal non Ferrari tires

2) The "K1" spec starts out with less tread wear. For the 245/35/20 size it starts out with 9/32 tread where as the normal tire is 10/32. Barely any difference but.....the 285/30/20 K1 Ferrari tire starts out at just 7/32 tread where as the normal tire is 10/32. You are basically losing 30% of tread right off the bat to save weight (more on that later).

3) The tread design pattern is the same but the grooves in between the tread columns on the K1 tire is wider. You have to see the tire side by side to see the difference.

4) The K1 Ferrari tire tends to be lighter weight than the normal tire. For the 285/30/20 size the K1 tire is approx 2.6lbs lighter. This doesn't mean its only from shaving down the tread of the tire because the overall diameter of both tires is exactly the same according to Michelin's specs.

5) Now here's the kicker. Since i originally ordered the K1 spec tires for both the front and rear just to find out now that Tirerack also sells the Normal version non K1 tire in the 285/30/20 size, I called to exchange the tires since i haven't mounted them yet. Now that i have both sets of the tires in front of me the K1 tire has a different profile sidewall and is also much stiffer than the normal non K1 tire. The K1 tire's sidewall is more rounded and has more of a stretched look while the normal version is a more traditional blockier sidewall (less stretch look). You can tell just by looking at the tire without them being installed on a wheel. The part that worries me is that the K1 tire will probably have stiffer ride comfort (better handling) compared to the non K1 version. I believe this is due to the K1 tire having a higher speed rating than the normal tire. Not sure.

6) The "K1" tire also cost more. TR has the rear tires for $406 each while the normal version is $359 each for the 285/30/20 size.


Alan