Need some help with choosing tires for 17x7 STI wheels
 

I've got the 17x7 STI wheels that come on the Series.Blue. Currently on some 215/45R17 Ironmans that it came with when I bought it last year.

I'm looking to get some Michelin PSS for DD and I'll also go to a few autox events throughout the year. The autox is just something I'll do sparingly for fun, I'm not looking to get super competitive in that area so that's why I've decided to go with the Super Sports.

I'm going to be installing some Eibach Pro Kit springs in the next few weeks so the car will be lowered about an inch all around. I'm hoping to get some input regarding tire sizes and what you'd all recommend. I was looking to get a slightly wider tire at 225/45-17 and was wondering if I can even push it to 235, but if I do that, what would the difference between 235/45 and 235/40 be? And if this is a bad idea please let me know why.

I should also add that the primary reason I am lowering the car is to minimize the wheel gap which is just about the only thing I dislike on our cars when stock. And if I could minimize it even further with a slightly higher sidewall that'd be great, but not a big deal if I can't or shouldn't.

Once I get this all figured out I'll be looking into what spacers I should get to have the wheels sit a little more flush. And I've done a ton of searching both on the site and on google including the site for better results. I got a lot of ideas but having a thread for my specific situation and goals is much better.

Good tire size for you is 225/45. Going up to a 235/40 is a little too wide and i believe the 235/45 is too tall and that will affect your gearing and speedometer reading. If you can get 17x8 wheels and fit a 225/45 that'll be ideal, but other than that you can still run a 225/45 on 17x7.

Thanks, that's what I was most worried about when thinking about going up even further. I love these wheels so I'll be sticking with them for the foreseeable future, so it's whatever works on a 17x7 for me.

With 17x7 wheels you are limited to the sizes Vital has suggested. (215/45 or 225/45)


Spacers - Here is a good thread. Guys are running 15-25mm front and 15-30mm rear on 17x7 wheels.


http://www.ft86club.com/forums/showthread.php?t=59838

Thanks, I'll probably end up going with the 225/45 like you both said. That seems to be the size I run across the most. I had actually read through that thread a while back and was thinking about 20mm in the front and 25mm in the back.

For ideal performance, and to better support the tire casing, you want the wheel width to not be narrower than the measured tread width. Ideally equal to 1/2" wider. The PSS in 225/45 has a measured tread width of 8.2" so while you could mount them it's way too wide for a 7" wheel. Ideally you would put that on an 8.5 and even the 215 would be better off on an 17x8.

It appears that the 235/45/17 PSS mandates at least a 7.5-inch wheel.

I've read on this forum and on others that the PSS, when pushed on a track, may not hold up very well to the heat generated?

"Depends". It will held up much better then most purely street oriented tires, and much better then eg. one-lap-wonder like RE71.
Some specialized track tires can do better, but PSS or PS4S imho will be more then adequate to have your share of fun on track.

I've heard the PSS doesn't hold up to the heat well either, but I figure for an autocross event where a run is about a minute or less it shouldn't be too much of an issue. Or am I wrong in thinking this way? I can understand at an actual track day, but autocross is generally much easier on the car.

PSS are tremendously overrated, IMO. If you're going to the track, get a tire that's up to it. I just got a set of RE71Rs for daily and track use. If I hadn't been concerned with tenths of a second in time trials I would probably have gone with Hankook RS4.

Particularly being width-limited to 215 or 225, I wouldn't bother with a Max Perf tire for street *and* track usage.

For the record the RE71R isn't a 1-lap tire, my fastest lap in practice (a 1:20.554) on Saturday at New Hampshire Motor Speedway (chicane/chicane) was 9 laps in. In the time trial I went faster every lap: 1:21.205, 1:20.554, 1:20.511, despite screwing up a couple of corners on laps 2 and 3. Won my class by less than a tenth :O

For the occasional autoX they will be fine.

a thing to remember is ones 215 may be as wide as another 225 but if you know you want PSS and did your reading here youd already know that :)

I appreciate the feedback. I won't be tracking the car, not in the near future anyway, I'll surely do it someday but that won't be for a while. It's my DD and I'll probably go to like 6-8 autox events a year. And even then like I said, it's mostly for fun, I'm not looking to get super competitive or anything. It's more of a release since I try not to do anything reckless on the road but when I'm behind the wheel of this car I can't help but feel like putting my foot down and having some fun haha.

Had these wheels. Ran 215 PSS. That was the right size.