Mario Yubeta, from Tuscon, Ariz., drives this 2007 Peterbilt 379. The owner-operator, leased to Diamond Trucking out of Phoenix, hauls petroleum products in the rig, which is powered by a C15 Caterpillar with 550-hp and an 18-speed transmission. Yubeta bought the truck in 2006 and has since added much of the chrome on the exterior, as well as a granite steering wheel on the interior and Rockwood products.