Sounds great! Has the perfect deep rumble that sounds rough and harsh. At highway speeds it's very quiet, so there's no hum at all, but when you step on the gas it makes the average noise I'm looking for. I've heard this muffler sounds more like a hot rod muffler compared to the Flomaster and Flomaster. When you let off the gas he makes that wap wap noise. This muffler is more like a truck muffler. Sounds great when you run through a traffic light for the first time in the first three gears. If you want a little more back pressure and torque for towing, use a dual inlet and a single outlet. I installed this on my 6.0 Chevy 2500HD and it sounds perfect.