6.4 exhaust fuel mileage

[Alexpaul09]

didnt know if anyone that's put aftermarket exhaust on their 6.4 has seen any better mpg's out of them or not!? I hate the look of the resonator hanging behind the rear axle it's just plain ugly!

 

[MADDOG]

That's one of the first things I did was to remove that ugly reso and swap in a Magnaflow muffler on my 6.4L powered truck.

Mileage did not improve with the muffler change. Once I put on a programmer and a custom tune, highway mileage did improve some.

 

[hunterdan]

On my 1500, I just had my shop cut the resonator off and run a piece of pipe straight back to the bumper with a turn down on the end. Looks a lot cleaner and the sound is a bit better. I'll need to grab a pic of it at some point.

 

[hunterdan]

Here is how I had my pipe routed after the resonator was cut off .

 

[Firebird]

Did it drone any without the resonator, especially with MDS engaged?

 

[hunterdan]

You can hear it switch over, but its just a light burble and doesn't bother me. Its noticeable, but it doesn't drone really, you can easily drown it out.

 

[hunterdan]

I've recorded and uploaded a few videos to give you an idea of the sound. Considering yours is a 6.4 it might be a tad louder.