Well, you really can't ignore durability as it directly relates to performance n any scenario that involves tire wear. Once heated, but with minimal use, higher grade tires will always possess more grip than lower grade tires.With tire wear on, however, lower grade tires will maintain their own higher levels of grip for longer periods of time than higher grade tires. As it is, I'm inclined to run Racing Hard tires on most every race car, both for the realism and the increased tire life. Very rarely do I throw Racing tires of any sort on a road car, regardless of how modified it is, as the lack of adjustable downforce (rear AND front) means there will still, invariably, be slip. Slip leads to wear (duh!). But I digress. The very short answer is that higher grade tires will always perform better when a proper tune is employed (they can exaggerate deficiencies in a stock tune).
