I have 40,500 on my rears and there 49 months old and my 2nd set of front have about 22,000 and there 2 yr 9 months old. The fronts are after i changed the camber setting from stock -.75 to - .125. The 1st set of fronts lasted 19,000 miles with the stock camber setting and now the 2nd set have all even tire wear with the new camber setting.
Intersesting responses. My last three new vehicles, a '93 Lightning, an '02 Lightning, and now my '07 GCSRT, have all gone through tires at about the same rate. I usually have to buy a new set every year. And yes, I usually wear them all out at the same time, usually without any crazy wear patterns. It seems I drive much harder than normal humans, since miine wear out so fast.