I think the difference is in the nature of our roads -- we tend to do much longer distances on smooth (well.. relatively smooth) interstates that have broad curves, so there is little rubber being scrubbed off the tires.

I have ~40,000 miles on the Goodyears, and they're about halfway through their tread. It's not an especially sticky tire, but it channels water really well and does OK in light snow.

Chip H.