I dont think I could have a gas powered work truck again. My first plow truck got 5 mpg plowing snow. Both cummins trucks get 10mpg plus plowing snow. It doesnt help that I like the screw around sometimes either. Both cummins are turned up is prolly why. I never did with the gas trucks even when they were mod'd.
Far as towing gas doesnt hold a candle to the ol cummins. I have never got below 12mpg towing 10k plus. I also make ~400whp in the one truck. It makes hills look alot easier then my 360 powered 1 ton with 488;s ever did.