How does it sound @ 75mph on the freeway? I'd love go with the PowerVault based on the dyno sheet, but I do too much city driving to have the drone of something that sounds like a hole in my stock exhaust system at 2700 rpms.

I don't want to make a rukus accelerating since whatever I do to this truck to increase horsepower, I'm still moving at a snail's pace compared to a true performance vehicle.

I'm intrigued by a muffler called the Aero-Turbine since they claim it actually accelerates exhuast gas from your system, providing more performance over just a straight pipe, but their dyno sheets don't seem to match up with their cliams.

I'm using their Honda Accord V-6 to base numbers off of, since all the rest of the engines they show are V-8's. The mileage gain seems disproportionate to the miniscule horsepower and torque gains.

I emailed them late last year and never received a response. I've been meaning to call them all week but haven't had the chance. It seems to be a neat idea anyways....