Nitrous
To replenish nitrous you need to either draft off the other cars on the road or perform jumps. To gain the most nitrous by drafting you need to draft for as long as possible and switch lanes right before you are about to run into a car. Use the nitrous you receive as soon as you get it to maintain your speed.
We have more cheats and tips for this game here, Fast & Furious: Legacy cheats
Comments for this hint