Thanks MT, I put them on to knock the crackle and possible drone out of the standard SS MF mufflers that come in the MF exhaust system and it probably made it a little to quiet! someone said they would take approx 6Db off the sound, dont know for sure however, it does not drone on the interstate and kinda sounds ok when you on the gas. here it is in my garage but I plan to get someone along side it while im out one day and record it.