[Pete_vB]

I swapped out my PS2s for Michelin PSSs in stock sizes on the 19" wheels a few days ago. Even though I've had PSSs on other cars, I'm still amazed at the difference these tires make. If I didn't know, I'd think I was driving a different car.

First, the bad: The turn in on the PSS is noticeably slower, and the car feels a fair bit less precise than with the PS2s. I suspect this is down to a significantly softer sidewall. I've always felt the 1M is extremely responsive for a stock front engined car; these tires noticeably increase the on-center dead area in the steering, and driven in the same way as the PS2s you'd be missing apexes by feet with the PSS- you need to adjust your driving style to turn in earlier. I have not played with upping the pressures yet.

That's it for the bad, on to the good:

First, grip: The PSS is much, much sticker, especially noticeable in putting power down. As someone who always drives with TC off, I can say that I have never stuck 1st gear with PS2s. That is not the case with PSS, and better yet when they do break away it is very progressive. When PS2s let go they really let go, sending the rpms to redline rapidly and/ or putting the car very sideways. The PSSs, on the other hand, are still doing lots and lots of gripping even when they are slipping. Suddenly the car is much easier to drive on and over the limit, with much more confidence that the car will not "snap" away from you even in bad conditions. Even in the wet:

Wet performance: Outrageously good. I did 14 laps at a very wet autocross yesterday with the Porsche club, my first autocross in the BMW. My friend and I were comparing A Stock cars back to back, his Cayman S vs my 1M, we were both on identical Pilot Super Sports, and we were the only cars there to have them. There were 44 cars, including a number of Porsche GT3s (one on hoosier wets), Porsche 996/ 997 turbos, M3s, a brand new 400+ hp Porsche 991 S, etc. Of all those cars on various wet tires, my totally stock 1M came in 2nd overall, and my friend in his Cayman took TTOD. I wish I could say it was all driver, and we are both good, but we both clearly had an advantage using the PSSs. I'd guess I would have been 3 seconds slower on the PS2s, and it would have been very difficult to drive with the TC off. With the PSS it was no problem, including holding long slides in the wet through puddles with power on.

Comfort: The PSS rides noticeably better.
Wear: Too early to say on the 1M, but on my previous car I got at least 2x the life vs the PS2.

Overall I think BMW made a big mistake not putting these tires on stock. It was almost as if the car was designed for them. I do wish the car was a little sharper with them on, but overall that's a small price to pay. I have a set of 18" wheels with Hankook R-S3s waiting to go on the car next to test; I expect them to be even stickier in the dry, no where near as good in the wet. The PSSs have set a very high bar for them to exceed. I'd call a switch to PSSs a "must do" mod, even if you have a little life left in your PS2s. Get those things off as soon as practical, you won't be disappointed...