Ken is right, mostly. There is no free lunch, it's a trade-off. I have Yokos on my other car and they are a little quieter and a little softer (not much) but the wear factor is much greater. At less than 9000 miles they are worn to the point of watching them and thinking about replacements. About the originals, 'tis true that the material changes as it ages, tends to get harder, the interesting thing about that is that it may not be of even hardness all the way through, the outermost part being that most affected by exposure to the atmosphere. For the first 100 miles or so the tires were downright "lumpy", after another 200 miles or so they quieted down and now seem very acceptable. The wear factor, as mentioned is negligible. Anyone have similar thoughts or expertise?