I mean, the last race i ran while i was changing my fuel during it i had two options becouse i wanted like fuel for 20 laps so it was for 19.8 or 20.4 and i wanted to have fuel for like 20.1 but it couldn`t be becouse i cant add half a liter. Its just for be more risky and try to be faster as the effect of less or more fuel is considerable.
Edit-> effect OR less or more fuel is considerable to effect OF less or more fuel is considerable.