my k5 still has the tires i bought it with, a few years ago. i'm not sure of their age. they have pleny of tread left, but the sidewalls have hairline cracks all the way around, and a few slightly larger cracks. all my other vehicles get the tread worn off long before anything else has a chance to wear out, but the k5 is not my dd. i can't take pics, at the moment (working hard, at the office. ha) but does anyone have a general suggestion about how much crack is ok? i want slightly bigger tires, anyway, for looks and a bigger footprint, but i don't want to drop the money if these have a good amount of time left.