MPG drop with new cat-back exhaust install

[BEAST MODE]

Hello everyone,

In February I installed a Borla S-Type cat-back on my SCREW and my MPG dropped nearly 3 MPG on both city and highway. It's been over two months and the numbers haven't changed. Has anyone else had a similar experience? It sounds nicer than stock, but I wasn't anticipating that kind of drop in MPG. I'm almost to the point of putting the stock pipes back on.

I know a person shouldn't buy this kind of truck if one is worried about fuel economy, but every little bit helps!

- Craig

 

[CarmanKyle]

Your foot is probably on the loud pedal more.

Fwiw when I had the MBRP turndown mileage was about the same. Its since changed to another muffler, mileage is about the same.

 

[Swacer]

In most cases, its entirely your foot and how you drive because you have an "expectation" of the sound you want to hear while you're driving, which is more aggressive than you've driven pre-exhaust.

Be more conscious of your driving and you'll see it go back up.

 

[Chinmasterflex]

Agreed. 3mpg is a pretty big change too. If you're certain it's not driving habits, maybe it's a maintenance issue.

 

[KOBRA2848]

If anything I think my gas mileage improved after the installation of my Corsa Extreme system. Not that I worry too much about gas mileage I have noticed that around town the gas mileage monitor sometimes shows 13mpg.

Mark

 

[dewalt]

Ford performance touring and gearhead tune gives me better than 600 miles of fun to a tank

 

[IHAVETWO]

I got better mileage with mbrp my wife drives truck now.mileage sucks,she likes the noise.beats the shit out of it.

 

[BEAST MODE]

Update

I'm not quite sure what the actual problem was, but I ended up fixing the issue along the way somehow.

I went through the cat-back and checked for leaks (there were none). I took off the CAI, cleaned everything, and re-installed. I then reloaded the 5Star tune.

Now I'm getting around 13 (city) and 17 (hwy) which is decent considering I have the 87 Perf tune loaded.