Well.....a 12" glasspack has to be louder than OEM muffler. Most OEM systems are tuned to be quiet......not for performance. That is why OEM systems have huge mufflers and resonators. Hopefully, the glasspack will be less restrictive, and the midpipe with mandrel bends will offer a better exhaust flow. All that I worry about is loss of backpressure. You do need some backpressure for torque. Don't forget what they say about horsepower selling cars, but torque winning races. All that horsepower in the higher end does not mean a thing if you can't jump off the line. And in this case, with my family station wagon, it doesn't mean a thing if I can't get up & go with my boat hitched to the back.