If you like a loud exhaust this ones for you. My F250 6.2 liter Ford "seems" to run smother and a little more power. No gain in fuel mileage (disappointing). I only had it on for one tank of fuel so my be not sure about a fuel mileage gain yet. Would I put it on again probably not with out an increase in fuel mileage.
Cost did not justify the end results
Installation of the Cat Back Split Exhaust Pt. #69116 was easy. Problem encountered was the steel exit pipes had to be slotted to get the pieces securely attached to the tailpipe. The clamps would not grip tight enough to prevent pipe from rotating down with the stainless steel tips attached. Very disappointed in sound. There is no %X93throaty exhaust tone%X94. Sounds just like the factory system. The sound was primary reason for replacing the factory system. The Cost did not justify the results.