Treadwear

[johntesi]

Yes, I've searched. I have a very simple question. Given the same driving conditions, what lifespan difference could I expect between identically sized tires rated 180 and 220, respectively?
Thanks!

[Doc@tirerack]

Maybe 20,000 miles for either tire. Unfortunately, the testing is not standardized across all tire manufacturers, so there is no cross reference stating that every tire rated at 180 will get 20K miles. If the manufacturer is the same for both tires, the only thing you can assume is that the 220 tire will last 20% longer than the 180.