Bad MPG after delete???

CaseysLTZ · March 25, 2016

Deleted butterfly valve and resonator, just to have clean look, dumps right after muffler. But it really seems like my mpg went to shit after that! It doesn't sound any different so it's not because I have my foot in it all the time. Any suggestions? Thanks

07Softail · March 26, 2016

It's because you have your foot in it all the time! LMAO yeah ok we all believe you!

RT

04badss · March 26, 2016

maybe the back pressure had a play in the mpg from the factory design of the exhaust system......

SouthernSilveradoGuy85 · March 26, 2016

Well my MPGs went down a little after I had my exhaust done, but that's because the sound made me go back to my normal driving style. With stock exhaust making it sound like a Prius I actually grandpa drove it around since it was my first brand new truck and had no sound to make me want to give it more throttle. Maybe you just think you're not giving it more throttle because I'm sure it's at least a tad louder than stock without anything behind the muffler.

Spurshot · March 26, 2016

maybe the back pressure had a play in the mpg from the factory design of the exhaust system......

CaseysLTZ · March 26, 2016

Lol guys it honestly sounds exactly the same as stock, except when I start it. And I've hear "back pressure" for years and years, is this real or what? Lol

CaseysLTZ · March 27, 2016

Bump

Victory14red · March 27, 2016

No. Backpressure has nothing to do with it. There's another thread here about exhaust and backpressure that I posted a fairly comprehensive article on how it works. In short, eliminating backpressure will have no effect on fuel mileage and only a positive effect on power. You can however go to a too large pipe and cause a loss in scavenging, but you wouldn't notice that except in a more high performance application where header tuning came into play. I currently have the stock manifolds and y-pipe to a 4" metal mulisha exhaust and have noticed no mpg loss. It has moved my torque curve slightly to where my trans is relearning currently however you haven't made a drastic change.