Home / Race Results / Click on the previous season and then look at your race from the season before.
If you attend races, then calculate the 1st 2 laps or the last 2 laps before you stop.. That is your fully pushing stint, so you'll have what the car uses at max.
If you don't attend, then you can take any stop.
If you put 40 ltrs in and by the end of the 1st lap you have 37.3.. then take the 37.3 away from the 40 and there you go..