In case somebody didn't notice yesterday: The fuel estimates in the menu are too low for the WTCR cars on Zandvoort, at least for the Honda.
The fuel estimates in nearly all cars on nearly all tracks are off by quite some margin. In general R3E tends to be somewhat generous so you end up taking far more fuel than you need, but in a few cases it underestimates. But of course it is also determined by the way you drive during the race... exact fuel consumption is rarely the same in free practice as it is during the actual race, particularly if you're fighting. Best bet is to just work it out for yourself. If you use OtterHUD it includes a fuel widget which calculates and predicts fuel requirements. I used it recently for an 80 minute FR X-17 race, and I literally ran out of fuel as I crossed the finish line. Pretty accurate.
Well, yeah, but these fuel estimates are also being used by the AI as far as I know. It should never underestimate the amount of fuel that's needed for a certain number of laps.