There is a weird thing going on, when i fill up my car, the pump goes clang -> empty after this, even if the tanks were almost full before, but if i refill several jurycans, it keeps pumping gas. ( i filled 5 steel jurycans, and is still not empty). Maybe i am wrong about this, but i ran out of containers to refill.
Also, on a separate note, i can’t reload a flamethrower unless is completely empty, and with only the first quantity available. Like, if i have 2 plastic bottles of gasoline, it fills only with 400units, then it refuses to load any more. Says “out of ammo” 
I found a workaround for this, unloading the second bottle in the flamethrower seems to work.