Rear tire width requirements in relation to HP?

I like my 295s cuz when Ima sliding sideways, I need all the slideways rubber I can get. With 275s that stupid pos car would want to swap ends on every stinking corner. Now with 295s,if I do get a little out of shape, I just put a little pedal on the clutch, and she snaps back and I got 'er under control again. I hate bustin' rims on curbs.(language added for effect)
255s were a joke! My S would regularly swap ends under spirited driving. I had to really be careful.275s were nearly as bad.
Somebody/everybody complains about the lack of sticky street 15s.And they are right.There are some sticky 15s but they are very pricey and sure don't last very long.I bought a front set of those back in about 2004. 245/50-15s. F1s I think were called.Man my S could corner with those. But they didn't last but 2 to 3 months of city driving, and started to lose grip at the halfway mark.
I tried some 325/50-15 BFG DRs in the stock rear tubs, but they are really tight with my lowered ride height, so I can't really blast around the turns. And on the street they don't seem to be much stickier than the crappy Coopers, so I don't run on them much. I save them for the track.
On the street,400 ftlbs will annihilate just about anything you can fit in a stock tub,all the way to 50mph,and beyond,so you might as well install the fattest, tallest thing you can fit in there. At least that's my opinion.