2007.5 Dodge Mega Cab 6.7L Cummins 4x4 with the 6 speed auto as a daily driver. With an AFE intake, full turbo-back exhaust, EGR delete, and a Smarty handheld tuner I get 20 mpg city, 25 mpg hwy.
My "play car" is a 1999 Trans Am which is currently under the knife getting a new engine, transmission, Ford 9" rear axle, nitrous, intake, exhaust, suspension, wheels/tires, etc... Basically, everything that connects to the car to make it go, stop, or handle better is being heavily upgraded.