Quote Originally Posted by paul huryk View Post
The point of higher rated tires having more stiff sidewalls. S & T rated tires are low performance pedestrian tires with lower traction and higher wear ratings, of course they won`t handle as well in the same size as a W or Y tire - then again, try to find these all in the same size...

I was referring to comparing a W to a Y tire, which are going to be close in most respects - temp and traction rating may be identical. The difference can be as little as a slightly lighter tire that allows heat to dissipate quicker and thus allowing a higher rated speed, or it could be a stronger material for the belts inside that can keep together at higher speeds and temps. Neither will necessarily add to sidewall stiffness.

I have two sets of tires on identical wheels here in my shop. One has a set of falken 615Ks, the other Continental Extreme contacts in the same 275-40-17 size. Both are the same speed rating, same temp and traction ratings. But the Falkens are 3lbs heavier each and have a much less wide tread (even with the same 275mm section width). The Continentals have less stiff sidewalls and ride noticeably better, but can`t match the Falkens for grip. Always a tradeoff...

Let`s not forget the load rating, which is very important for identifying a tire to be able to keep together at speed. A 94 rating in the same size is not the same as a 102 or 105 when it comes to high speeds. In max speed cars, you want to be around 50% of the max load rating (or less) to assure the tires won`t come apart.
I`m not making a comment simply to argue. You seem to be focussing on issues beyond the scope of my simple statement. I give the S & T ratings only as an example of not needing to go to the highest end tires to see the difference in how they handle. S & T are just two examples of speed ratings that are close to one another yet feel very different even on a big sedan. You can usually find similar size tires between these two ratings. No where have I compared S & T tires to W & Y tires. That is a distortion of what has been written. You certainly don`t need to push a tire to its limit to feel the benefits of a quality tire at a slower speed.

I think I was also fairly clear in my last post that comparing tires from more than one manufacturer is like comparing apples to oranges in how a tire feels. Not sure where you were going with the Falkin/Continental comparison. Though two different manufactures give their tire a tread wear rating of 300 does not mean they deliver the same number of miles. Tread patterns alone will make 2 tires handle quite differently. Your point about the Falkens being heavier than the Continentals are a perfect example of tires feeling different from one manufacturer to another. Tire weight and tread pattern often varies between different speed rated tires of the same manufacture.

As you`ve just stated, these two different tires even being the same speed rating feel different. As this is true, so is it that tires of a different speed rating feel different. I believe that if you asked most people to describe that feeling the word stiffer would be used often. If that`s not how you would choose to explain this I`m fine with it.

I believe that if someone who knows their car were to push it given the OP`s example, will notice a difference. The premise behind my comments were that someone use the tire to its ability, not how it feels driving down the freeway. 4 tires of the same manufacture, same design and same speed rating will serve you best from a performance perspective. Manufacturers don`t recommend mixing speed ratings. There`s a reason for this and I support that mindset. Not trying to make a point beyond that. Nuff said on my part.