Amazing the Dodge Hemi engine won't cost you as much at the gas pump as you'd think. It gets a respectable 17 mpg around town, but lifts the mileage figure to an impressive 25 mpg on the highway, thanks to its Multi-Displacement System that shuts down four of the eight cylinders during highway driving, a time when they aren't really needed. Reacting in just 40 milliseconds to your foot on the pedal, it fires all eight back up whenever you require some additional muscle.