you may not be aware that most pans are flat and therefore the fuel tank is not 'tilted' in any way. Anyone any serious suggestions?
A pan may be flat but most aircraft wing tanks are actually tilted due to the dihedral! The Bulldog tanks for example are over half full if you can see anything in there, can't recall exact figures for Pa28, but certainly IIRC you have an hour plus if you can see fuel in both tanks.