This past weekend I stopped by a muffler shop out in the stix and my muffler and resonator some how fell off. I love the growl that my CTD now emits, but am perplexed about something.

It seems that my fuel mileage has now dropped about 15%. I know that some of it is because I now have a new affinity toward touching the go pedal closer to the floor. But I also played with the cruise control on the highway holding a steady 60 mph and noticed where I used to maintain a 21 mpg, I now maintain closer to 18-19 mpg.

My question is what gives??? I thought by reducing the exhaust system back pressure my mileage would have gone up.

One comment I will make is that I now notice a lot more low end grunt and power.

Any comments on this is greatly appreciated.

FWIW I replaced just muffler and resonator assy. with 3" pipe

Thanks!!!!

Gary

 

Do not know much about the computer fuel milage machine in your truck, my advice would be to track it manualy. As far as the straight pipe, hook your trailer up and go for a spin up and down the highway and get ready to listen to the drone that will most likley drive you crazy. Now some say it doesn't bother them, it was a killer in mine when loaded and pulling a heavy load, around town it was great, I did away with it when I had a flow thru muffler installed in the long area of pipe I replaced the original with, my mileage improved as most if not all that I have had contact with. Goodluck,,,Rick

 

The computer mileage thing is only valid w/ a totally stock vehicle...alter anything and it will mess up its calibration.