21/8/2021 · Average barge fuel consumption on the Mississippi River from Iowa to NOLA export grain elevators was 544.5 net ton-miles per gallon, with a 35 percent backhaul rate. On the Upper Mississippi River, southbound tows achieved 953 net ton-miles per gallon with all barges loaded while the northbound tows achieved only 243 net ton-miles per gallon with a 37.7 percent backhaul.