If I have my back turned to a vehicle and I only hear the sound coming from the exhaust pipe.
I can distinctly tell, that the sound I'm hearing is coming from a 50's Chevrolet Six cylinder truck's straight through muffler.
Its kinda like the old Plymouth car starters, they had a different sound when cranking the engine.

Chevrolet should have trademarked the sound, like Harley Davidson tried to do with there V-Twin engine motorcycle sound.
Ultimately they were denied trademark status on the "potato-potato-potato" sound.
Sound trademark

Never the less there's nothing like the sound of a purring Stovebolt Six.