First trip with my new 90 gallon aux tank. Fueled in Abilene, Texas. Drove to Mesa, Az. Hooked up to a 35' Avion 5th wheel and drove back to Wilcox, Az. 1185 miles and took on 60 gallons. Drove back to Granbury, Texas with the Avion and still have fuel left in the Aux tank. Did'nt have to use my main tank. I love it!!!!!!