I recently put in a Magnaflow 14 inch muffler to replace the stock one in my 08 Ram 1500 4.7L Quad Cab. I am noticing a significant DECREASE in gas mileage. What would be the cause of this? I thougt a performance muffler if anything would increase gas mileage, not decrease. Could someone shed some light on this? Thanks

 

Are you putting your foot into it a little bit more than you would normally to hear it?

 

It shouldn't cause you to lose any gas mileage unless you're getting on it more like truckin said. Try resetting the pcm by pulling the neg. battery cable for 10-15 mins. and see if that helps.

 

I tried disconnecting the negative terminal, but didnt help. I may be guilty of stepping on it from time to time, but i am reading 130 miles at half a tank of gas and that is ridiculous. I use to get about 18 mpg

 

Weird, how long since you had the muffler put on? Who did it and did they change the pipe size or anything else?

 

sounds like a crock pot full of chit....sounds like you like to hear it ...alot of ppl do that put on a badace muff and then accuse the muff of the drop.....

 

That's what I was thinking.

 

The same thing happened to me. It takes about a couple tanks of gas for the PCM to figure out the increase in flow.

 

I used to get about 12 before my chitpipe intake and now I get around 8-9 but thats because of my right foot and the tune my ears like to hear while driving.

 

I am getting mine put on at 8am in the morning. I will see if there is a difference.