No, just accept the default fuel level.
You are given the option of 3 levels of fuel, I can't remember the terms the game uses, perhaps Aggressive, Standard, and Less Aggressive
Aggressive = Less fuel and less weight (the car is more nimble), but you must spend much more time in fuel saving mode (Lean Fuel) to get to the end of the race
Standard= = A kind of optimal fuel setting - You can spend most of the time at the Standard fuel mix, with quite few laps on Rich Fuel, but you will have to use some fuel saving at Lean fuel mix during the race. If you spend the whole race on Standard fuel mix, you might not make it to the end.
Less Aggressive (don't remember the real name) = You are carrying more fuel than required, which makes the car heavy and harder to handle at the beginning. You can use Standard fuel mix throughout the race, and quite a lot of time at Rich fuel mix. You are unlikely to need to use the Lean fuel mix during the race.
