[rotorwrench]

In aviation operations we were always instructed to keep the fuel tank filled to the top. This kept the posibility of condensation to a minimum which would also reduce the chance of corrosion. This doesn't always work in the automobile world since motor fuel is not the same formula and most older vehicles have steel fuel tanks. Aircraft tanks are generally made from aluminum in either welded assemblies or wet wings and most modern aircraft have synthetic rubber bladders in there where practicable to aid in crashworthiness.