The phrase "exhaust growl" refers to the loud and deep sound produced by a vehicle's exhaust system, typically when the engine is running at high speeds or revving. Full definition
Once you hit 3,000 rpm or so, the car takes off nicely, with a throaty exhaust growl. (automobilemag.com)
The new exhaust growls with a menace missing in the standard Mustang GT. (automobilemag.com)
The stiff ride, quick maneuverability and low exhaust growl emphasize the car's commitment to performance, while its conservatively sporty styling and spiffy interior underline its pitch to the family. (articles.orlandosentinel.com)