We just got back from the coast. I didnt put it on paper but according to the computer we got 24 going from Stanton tx to Freeport. we got 23 coming back. We usually get 12 when towing. i dont know how accurate the computer is. I have a gravity flow tank and fill up as needed. when we get to the station to fill the tanks we generally put in 4 or five gallons more than the computer shows. some times but not often i put in what the computer shows. Again I am trying to see if the price for the diesel is justified. Thanks for your real world expierences