Yeah...LOL...I guess I am. You spend any time at the track? Have you run different width tires with different aspect ratios and determined the differences in traction and performance? I said that a slightly (275 vs. 315) narrower tire with a more advantageous aspect ratio will hook better. You really think you can dispute that?
Who said "all 50-series tires" have the "same" sidewall height? It wasn't me. All I'll stand by the assertion that a slightly narrower, taller tire will hook harder than a 40, 35 or 30-series tire will.
So then you can explain why a 255/50-16 DR will leave harder than a 275/40-17 DR, right?
I've seen it many times at the track. Maybe you can also explain why the big-dog DR racers don't run 315/35 DR's...they run 315/60's and 345/55's. Same width, shouldn't make a difference, right?
S.

 

I don't think anyone is going to seriously dispute that the 275/40's the SS's come stock with hook better than the 245/50's - simply put, the wider tire hooks better. Been there, done that, got the T-shirt.

 

Drag tires act different than street tires. Also don't forget about total tire hight and rims size. Bigger rims = more rotating mass = slower.

 

LOL...sure you have.
You're not only comparing a different model tire, but a closer width and aspect ratio. Gee...what a surprise, a 275/40-17 Eagle F1 has more traction and a softer compound than a 245/50-16 all-season M+S rated tire.
I'm not forgetting anything. A 275/50-15 is as tall as a 315/35-17. One will work better in a straight line, one will work better in the twisties. In general, total tire height usually remains the same (unless you're looking for the "bling-bling" ). Therefore, going to a larger wheel means a shorter sidewall. I seriously doubt GM is going to use 17" wheels on its flagship Z06 (Z07? ZL1?). Look for 30-series tires, and a wafer thin sidewall for the ultimate handling characteristics.
And "drag tires" (I'm assuming you mean DOT's, slicks, etc.) do act different because of their construction (bias ply vs. radial) and the fact that most of them come with a rather tall sidewall (most manufacturers don't list the aspect ratio). That is exactly my point.
MT recently released a 26/11.5-17 ET Street. I'll be running them on the GT. Admittedly, they'll work better than a similarly wide 275-40 radial (or DR), but they won't work nearly as well as a 26/11.5-15 ET Street (or even a 26/10.5 ET Street). When you eliminate the sidewall's ability to store and release energy, you decrease it's ability to conform upon acceleration. Instead of acting as a cushion between the wheel and the ground, the tire transfers power without storing energy to release as it starts turning.
S.