What is the the best dual exhuast to have that will give you the most mpg and hp gains with a pretty good sound to go along with it. thanks

 

magnaflow

 

get a tuner. an exhaust system isnt going to give you a noticeable power gain.

 

Not entirely IMHO, I picked up noticeable torque and better accel with a free flow exhaust. Much different from the restrictive stock muffler and piping. I had a back pressure test done and it was much lower as well indicating more exhaust exiting than the stock setup indicating overall increase in efficiency. Keep in mine this was not with a STOCK air cleaner assembly.

 

Magnaflow.