I have a 2013 Chevy Impala V6 and when I push the throttle down the engine has a throaty growl, sounds good but I can't imagine why it makes it. Once the speed is accomplished it quietns down. Anyone have an idea what this is.
Well, a couple of things spring to mind:
One, the silencers may have blown the silencing material out or,
Two the exhaust system could have been changed recently...
Three, it could be an intake noise - if the air filter has been removed or it may have failed.
However, funnily enough there are several people who would pay good money for that noise :)