Was talking to an old friend this weekend who mechanics for a World Superbike team (he has a broken arm so missed the crappy weather in Monza this weekend) and he says that ambient temperature has a major effect on tyre wear.
Those in warmer climes who ride in 90F+ temps should expect to get up to a third less mileage from a tyre.
So, if those of us in cooler areas are getting 8k miles from a rear PR3, y'all in SoCal/Texas/Fluhrida will probably only get 5k.
If yer getting 5k in Oregon then you really need to SLOW DOWN before you kill yourself.