I have run through 4 sets of tires on my car,
215/50R16 KDW -from factory -24kmi
215/50R16 KDW -from tirerack -27kmi
205/55R16 KDW -from tirerack -22kmi
225/50R16 GSC-D3 -from tirerack -28kmi
All of my tires have been run down past the wear bars so the wear milage is rather inflated.
I liked the KDW for wet traction and handling, but then they always went out of balance by the end. BFG kept assuring me the next set would not do that.
205 is just plain too narrow, maybe with a LSD and some suspension tuning.
225 have the bulge look, and tend to plane a bit more in my opinion.
215 is perfect width for a stock svt, and 17s are probably the perfect diameter, but I haven't opted for the upgrade.
The Goodyears are by far the best, but you will piss off the people installing them on 6.5 rims. I have never had this stable of a tire in sweeping corners. Down side is ofcourse cost and low temp traction (not worse than the kdw).
Personally I would recomend you stay with your 17s and if you don't mind the lower profile go with
these.
Under $400 shipped after rebate. Do watch the load rating though. Get them installed for ~$40-60
Not bad for Y rated sick tires.
Oh forgot one thing, don't autocross these tires, they will perform fine, but they will wear like hell.