If someone is tricking the fuel flow sensor and using more fuel than the rules allow, then the car has to have more fuel onboard. The FIA compares what the fuel flow meter says was used during the course of the race, to the pre race manual measurement minus the post race manual measurement. Thus the fuel load report would have to be falsified or the numbers wouldn't match.
For a few races in 2018 this is why.
https://www.formula1.com/en/latest/arti ... kU2KA.html
Vettel had this to say about the thinner tires after being able to compare them the the old tires back to back.Pirelli found in pre-season testing that the new asphalt at Spain’s Circuit de Barcelona-Catalunya produced more grip and less tyre wear, which means more rubber stayed on the tyre which in turn can lead to surface overheating.
As Great Britain’s Silverstone and France’s Paul Ricard circuits also feature new asphalt for this season, like Barcelona, Pirelli opted to reduce the tread depth, and therefore the amount of rubber on the tyre, for those three races.
“This was a recommendation that we ourselves brought to the FIA – as we have done in the past at some races – because it is less disruptive than nominating harder compounds, which was the alternative,” said Pirelli’s Head of Car Racing, Mario Isola.
https://www.autosport.com/f1/news/13605 ... or-ferrari
For 2019 they used thinner treaded tires for every race, Because all teams naturally gain downforce and power every season. If they had used the thicker treaded tires used in most of the races in 2018, teams overheating the tires would have probably been the norm."Normally you don't get the chance to revisit these kind of decisions that are made," he said.
"But we did now with the day that we had today, and I think the result is that, if we had the normal tyres on Sunday, we'd probably even be worse off.
"So I think it was the correct call, and it was our fault not to have the same tyre wear or life as other people."
Look at this year so far, teams are running less downforce than the normally would because the tires can't handle what the teams are now able to generate.