Originally Posted by loesch
More rubber in contact with the road = more traction. Less rotational mass = faster acceleration. +1 death to run flats. Why bother when I can press the SOS button on the roof and get a free fix-a-flat.
Less rotational mass? A wider tire, of the same diameter, would weigh more and have greater mass. Tire weights vary by manufacturer/model a few pounds, most likely when you go with a wider tire, you will have a heavier tire (of course RFT vs non-RFT will make a difference in weight, if that is what you meant by less mass?).