The muffler helps eliminate sound that comes from the exhaust system by way of acoustic soundproofing. An unavoidable side effect of muffler use is an increase of back pressure which decreases engine efficiency. So choosing a quieter vehicle or better engine efficiency does become a common debated question for truck owners. For those who prefer a quieter truck we carry after market mufflers from manufacturers like MBRP, aFe Power & Banks. If you are unable to find what you are looking for please feel free to give us a call at 1-563-588-2708 and one of our experts will assist you with any question you may have.