I have a 2004.5 and need some advice if its worth the investment in a aftermarket muffler to help fuel mileage.

 

Probably won't see much (if any) improvement in fuel mileage but you should notice lower exhaust gas temps and better throttle response/slight gain in horsepower if switching out the stock muffler for a aftermarket one. Just ask around here on the board and you will get a variety of opinions. I run a Dynomax bullet race muffler (straight through design) and I love it. Deep throaty sound but not as loud as straight piped. .

HUMP

 

Dhackett,

Hump is probably right jusy changing the muffler won't jump the MPG's, but it starts the move by lowering EGT's. If you can keep the EGT as close as possible to 600 degrees pre turbo you are getting the max BTU use of the fuel and therby the best MPG etc. Add an intake and a good module/programmer and 2 MPG is pretty easy to get to. Call us if you want we have a bolt on 409 stainless (same as the rest of the stock systsm) MBRP performance replacement muffler that bolts right on, even has welded hanegrs to reuse the stock rubber mounts etc.

Mark @ DPPI