Replace stock muffler with a Flowmaster muffler?

[JamesK]

Several people have told me i can get better gas mileage - as much as 10 mpg more - if i replace the stock muffler with a Flowmaster muffler.

Is this accurate? Should i get a Flowmaster exhaust kit as well?
What about the K&N air filter kit?

Please allow me to benefit from your expertise!


My Jeep is a 2008 Liberty Sport 4x2, if that makes any difference.

 

[Marlon_JB2]

I don't know about 10MPG, maybe 1MPG, 2MPG as a best case scenario.... but you might in fact see a mileage increase as the engine can breathe better.

 

[06Liberty]

Your mileage will DEcrease...simply because you'll be mashing the pedal more often so that you can hear your new noisemaker. Seriously though, if you drive it the SAME as you normally do then you may see a slight increase like Marlon said....but definately not 10mpg. Same goes for the K&N, probably not a big enough difference to really be able to tell.

 

[JeepINgeek]

Once again going back to PT Cruiser experience. I was told that modding my intake, and putting on a high flow exhaust would improve mileage. So, 1 modded intake and 1 $300 mandrel bent BTG exaust later i went from roughly 17mpg to like 12! MAN THAT PUPPY WOULD MOVE!

Back to stock exhaust on the Liberty and have no plans to go down that road again.

Nuf said.

 

[Dave]

Once again going back to PT Cruiser experience. I was told that modding my intake, and putting on a high flow exhaust would improve mileage. So, 1 modded intake and 1 $300 mandrel bent BTG exaust later i went from roughly 17mpg to like 12! MAN THAT PUPPY WOULD MOVE!

Back to stock exhaust on the Liberty and have no plans to go down that road again.

Nuf said.

You forgot to mention "the improved exhaust tone" ......that's what you will get.

Now....."Nuff said".

Dave

 

[JeepINgeek]

Lol ya ya ya! oh and dont forget once you do thta you have to put in HIPO coils, expensive plugs, then youre going to burn through brakes and tires, not to mention those u and cv joints are going to be complaining