Since fuel mileage is now a bigger factor in FM6 than it was in FM5 or earlier (the car stops, dead, end of the line if you run out), and I can dump a full tank in a McLaren P1 in 1.3laps of the Nuremburgring (GP + old track).
It would be nice to get gas consumption metrics as a variable to track for cars so you can make decisions on cars for endurance racing based on fuel use to possibly avoid a pit stop.