go full size,more room, they work less harder and just keep your foot out of them, my 03 sierra Z-71 gets roughly 650km per tank, city /highway mixed, but no shortage of space or power when i need it, i pull a 21ft bassboat no problem and the 4x4 is bliss when you need it, maintance has been low, most full size trucks have good towing power, it just boils down to preference, with mine it rode better than anything on the market at the time.