The site below has possibly the best description of the whole fuel temperature saga in Brazil:
If everything in that article is true, I can’t believe how sub-standard the whole measurement process is (of both the fuel temp and the ambient temp).
In summary the article claims:
- FOM measure the ambient temperature as 37 degrees Celsius, while Bridgestone and Meteo France measured it as 33 degrees Celsius. Meteo France supplies all the teams with temperature information.
- The FIA measures the fuel temperature at the bottom of the fuel rig, yet the regulation states a requirement for the temperature of the fuel at the point where the fuel enters the tank of the car.