How are engine sounds in racing games played ?

For example in forza, the game plays engine sounds based on how much we press the button. Are there different sequences of clips ? If yes how do they blend so well ? Or are they synthesized dynamically ?

There are so many parts to it as well - when the gear shifts, when you suddenly slow down at high speed, when you suddenly accelerate from stop. They all seem very realistic.

Edit: Thanks for the great answers everyone 🙏