I think all cars should have reserve fuel tanks, where they have a laps worth of extra fuel on board (uneditable) which they can drive on to either get the cars in the pits or just to the chequered flag. However, during this time the car can only go of the pace they'd have with a puncture, and PL's become completely ineffective.
Many have mentioned the 'rolling to the finish' dynamic with momentum, but IRL the cars HAVE to make it back to the pits without running out or they get punished. No matter what track, I don't think momentum could let you finish an extra lap from any point before the line. If there wasn't the hairpin, Canada would be close though but that isn't even on the game.
It happened to me in beta the other week were some how I managed to cancel my stop... so about 4 corners into the lap the fuel read 0. The car still managed, however slowly, to cover nearly half a lap....
Was that the car free wheeling or did the drive enter some form of "ultra fuel save". As if its free wheeling I think it might need to be tweeked a little. I believe there would have been way to many braking and acceleration zones to cover that much of the track free wheeling.