When using 1/2 tank of fuel, the auto switch doe not work. On two occasions, I ran out of gas, when it said I had 100 or so miles left. I record all flights and save what I want. I zoomed in on the fuel gauge on take off and the gage was on "R" tank in the white letter. It stayed there till the plane ran out with over 100 miles left. 3/4 of full tank, no problem.