My rear drive S was wrecked by a red light runner and I bought a 3. These chains were used for a total of under 20 miles to get me out of W Seattle where I took them off for the plowed highway until I got to work in Renton. I think I did this 3 times. They require no modification to fit both tire sizes and it appears they have been re-branded, not redesigned, since I bought them. If you have a 4wd you may never need them but if you get caught at Rainier or the pass without them (or get stuck) the cost is way more than the $100.