So I currently have a 01 Sierra Z71 ext. cab. I have been tossing around the idea of getting something a little smaller to 1. lower my payment, and 2. save a little on gas. I have been looking at the Nissan Xterra, Nissan Froniter, and Toyota Tacoma. How are these on gas, is the supercharged Frontier good on gas? ................also, I would be looking at the crew cabs in both of the trucks.