First of all, I don't know the correct way since it is not known how exactly nitro behaves. And you may have noticed that AI races differently, for example it does not lose as much speed in corners and can take much sharper turns (even while airborn). But a few tips:
- yes, nitro can help you accelerate
- try to find other sources of nitro, like jumps, near misses and so on
- nitro can help you reach a speed otherwise unreachable, which you soon drop when turning; you may try to fire the nitro at the beginning of a longer straight course - you reach top speed faster and you can maintain it even when nitro dies out
And some more regarding hunter races:
- having better PR does not grant success in a hunter race, since your opponent already has an advantage. Having to boost your PR for 100+ points just because of one single race (already labeled as easy) is something very frustrating, but reality
- therefore, do not even look at suggested difficulty rating
- if you do not reach your opponent while racing without apparent errors, then you need a car upgrade more than just a change of technique
- if you reach him, but still can't win, you may try to bump him - it won't help many times, but sometimes it may, and sometimes it is the only chance you have