Actually, the EXT also has P265/70R Goodyear tires and rides on an automatic load leveling suspension like our Z66 counterparts. It has a height of 75.6," length of 221.4", and a width of 79.5" according to the brochure which probably supplies the info used in many of the articles about he EXT. However, the Z71 Av lists a height of only 73.6," a length of 221.7," and a width of 79.8." The EXT probably lists a height that is 2" taller than the AV because the Roof Rack is standard equipment on the EXT but not the AV. The cladding around the AV would seem to be the explanation of the AV's greater width and length. Another interesting fact is the EXT boasts a ground clearance of 10.7" versus the Z71 AV's 8.8." This must be due exclusively to the 4wd vs AWD systems and their respective transfer cases. All you 2500 AV owners are saddled by an even lower 7.0" ground clearance due to the 16" wheels and the larger fuel tank or different rear suspension (leaf springs vs five-link coil spring) you have under your rig. Some things just don't make sense. But, a picture speaks a thousand words and .......... well lets just say the Chief may have disproven some of our uptown cousin's claims.