What are you doing that has you towing cars/trucks all the time?
My primary tow rig is a '89 K3500 with a 454, and it won't beat 10 mpg empty! But given the higher cost of Diesel I don't feel real bad getting less milage and most days I'd rather hear that V-8 rumble rather than smell Diesel.
I'm not sure its completely rational, but I prefer the gas motors for my trucks.
