So far I haven't run out in my '61 dispite not having a gauge or the origonal reserve tank in it. I had more than a few horrified stares when I had several plastic 2.5 gallon gas jugs bungeed to my roof rack. Just stretching its legs to get some fuel for the mowers. I never passed a gas station when it was getting 9 mpg. Now it gets 19 on premium. I should be proud of the 110% improvement right