Originally Posted by: lanciastratos73 
My guess is that it's a sound patch so the car sounds more like a V8 rather than a 4 cylinder. There were a few posts pointing it out, maybe they listened and patched it.
Wouldn't make sense to patch one car sound and forget about the rest of the cars that need a sound fix. If Turn 10 does finally decide to fix the all the wrong engine sounds, they'll do it in one major update.