When are brand new tires considered "broken in"? Poor steering response on 15s compared to 17s.

[SeanBonham]

You mentioned a bike tire. It's a good analogy, a 20mm road bike tire can take 110psi, a 2.25" mountain bike tire is ran from 30psi to 50psi. The more volume a tire has the less pressure is needed to inflate. Tractor tires are ran at 10 or 12 psi! How weird does that sound!?

Any tire installer will tell you to lower your pressures asap. You will wear the middle of that BFG pretty quick. Your 15"s have more volume, thus need less pressure. Sidewall flex (as I understand it) has much more to do with the tire design than a few pounds of pressure. Try going to 36/34. Air is free after all

Lower pressure gives you much more of a contact patch = better grip.

 

[commonplatypus]

I will throw my support behind that. Ran my Pilot Super Sports at the track on 33F/32R and they handled amazingly well! Better than ever this last week and didn't overheat and melt like I was anticipating.

 

[parapraxis24]

I have these but in 205/45/16 and agree that the quick turn-in is not there like on my previous tires. Which was surprising because the previous tires were all-season Yokohamas. It probably is a few things, but I'm not certain if this is the actual reasoning but one: the larger sidewall removes a bit of that stiffness. Two, the tires are wide, like really wide for a 205, like 8.1" vs 7.3" of the Yokohamas.

On the upside, they grip excellently, I can push the car harder before the tires start screaming at me. I'm happy with my choice, but I did notice the same things you did after having them installed.

I will say, check your alignment as well. Mine apparently was way out (most likely from installing the TB Performance traction bar, and stupidly removing both bolts at the same time) and the turn-in was much better after getting an alignment, though not quite as good as it was when running the stock 17s.

 

[M-Sport fan]

Part of the problem is also that these are first and foremost a summer UHP STREET TIRE, (even considering as great as many say they are on a road course for a 340 tread wear donut) and as such, they have by design and on PURPOSE a much more flexible, 'comfortable', and softer sidewall construction. (Given the same profiles of course.)

Something is WRONG IF they did have a sidewall as inflexible, and rigid, as the 200 tread wear and below autocross and R compound road race rubber.

 

[Genghis_Bob]

+1 for alignment. You can't expect a 195/55r15 tire to feel the same as a 205/40r17. I went with 205/50r15 dunlop dz102's on 15x8 team dynamics and i wouldn't describe the change in feel as "slower" turn in but maybe a little less "direct" steering feel but not by much for me and i flog my car regularly. The bfg sc2's are supposed to have fairly stiff sidewalls but i personally think that a 55 series sidewall tire is going to be too tall for this car unless you're getting into some serious off road rally stage stuff. I considered the sc2's when i was looking at 16 inch wheel options and would have went with them if they offered 205/50r15 or even 225/45r15.

Whats interesting is the only other guy that i know of that runs your exact combo i think posted in the meaty tires thread and ended up going with a different tire/wheel combo because something didn't feel right at freeway speeds, but he was having issues with hub bore diameter on his team dynamics wheels for some reason which may or may not be related. just food for thought. I would go with a 205/50 or 225/45 and a good alignment and see if that helps. I'm happy with my 15x8 setup and i know most other people are happy with theirs, good luck!