BMW M3 GT2 - I stumbled upon this and I'm confused...bacause this car is using a V8 engine and it just sounds like a 4 cylinder...a beefy 4 cylinder, but a 4-cyl nonetheless
A very simplified "rule" is that when you double the amount of cylinders the engine note keeps similar. Main reason why the so called american V8 sounds different is that it has a cross-plane crank (versus flat-plane like we have in most 4-pots and in the typical italian V8). Engine with cross-plane crank fires in an uneven rhythm, but engine with a flat-plane crank fires in an even rhythm.
You might want to try and find different audio samples of different engines.
straight 5 vs V10,
straight 6 vs V12,
V8 vs V16.
Note is very similar when you compare these together.