"If your car comes with a Cooper All-Season that has a load rating of 89 and you switch it out for another tire, lets say ultra-high performance all-season with a load rating of 95, that's the same size."
I'm not CapriRacer, and don't have his knowledge, but I have never seen a "better" tire with a higher load rating in the same size. AFAIK, you will find LT (load range ???) tires that handle more load, but high performance ... as in racing or cornering ... they aren't. Can you give an example of one?
"How about sidewall stiffness? I didn't see much mentioned in the article about that. Test: Seat two tires on identical rims. One with load rating of 89, one of 105(big jump) and a known stiff sidewall. Decrease the pressure on both as much as possible without breaking the bead. Now measure the depth of the cup in that tire. There's no way in [censored] they're the same."
I believe that if both tires are recommended for use with the rim width in question, you will get a good contact patch over the range of recommended pressures. If WELL below recommended, will it cup? I'd frankly not expect it if rim width and tire size are within mutual specifications.
Now extrapolate this out to running pressure.
I'm not CapriRacer, and don't have his knowledge, but I have never seen a "better" tire with a higher load rating in the same size. AFAIK, you will find LT (load range ???) tires that handle more load, but high performance ... as in racing or cornering ... they aren't. Can you give an example of one?
"How about sidewall stiffness? I didn't see much mentioned in the article about that. Test: Seat two tires on identical rims. One with load rating of 89, one of 105(big jump) and a known stiff sidewall. Decrease the pressure on both as much as possible without breaking the bead. Now measure the depth of the cup in that tire. There's no way in [censored] they're the same."
I believe that if both tires are recommended for use with the rim width in question, you will get a good contact patch over the range of recommended pressures. If WELL below recommended, will it cup? I'd frankly not expect it if rim width and tire size are within mutual specifications.
Now extrapolate this out to running pressure.