on the track is a different story, expect the car to drink it in that scenario.
as its only on when you are on boost and around town thats never an issue as you cant be on boost for long periods, on a race track however most of the time you are out there you are trying to keep it on boost.
for a car thats street only, a small tank is great. the more track use it gets the bigger your tank should be or you will be filling it after every session.