ModernMuscle

if its the general uhp, stay away.
I tried some of those out for 2 days, and couldnt keep from spinning my back tires.
if you look, you get 1/2 the width of tread (due to all the voids)

I would suggest the BFG Gforce Sport or the gforce kd (comes stock on the roush stage 2-3) or the kdw (not the stock design)
They aregreat tires.
I run the Nitto 555s and love the hell out of them. but also like the goodyear GSD3 < these are AMAZING. high, but amazing wet/dry/and track grip

drbobvs

255/45 all around. You can get Toyo Proxes T1R for about $175 installed at STS tire. Nitto 555's somewhat less.

Norm Peterson

BFG g-Force Sports are pretty good at either acceleration traction or lateral grip as long as you're only doing one or the other. They aren't nearly so good at combining both - think corner exit or accelerating out of a tight turn in a lower gear - so they might work as a drifting tire.

18 x 8.5 is normally only an approved width for up to 255/40 or 255/45, though you might find one or two mfrs that will list it for slightly wider tires. Generally, 265 and wider will show a 9" as the minimum. This isn't quite a "pass-fail" thing where half an inch "too narrow" is guaranteed to result in unpleasantness, but a line does have to be drawn somewhere.

My take should you decide on your own to run tires on wheels that are outside the standards for minimum (or maximum) rim width is that you're accepting some additional risk on your own. Ultimately, that's your decision whether you know what you're asking of the tire structure or not. On the other hand, it is not appropriate to make the same recommendation to somebody else (who has the right to expect technically correct information instead of "it's close enough for me").


Norm