I've been told if you take the muffler off it robs gas mileage...is this true?

 

i couldnt tell a diffrence but that was only the muffler on a 2003 5.4 cats and everything was still stock and on there.

 

i think most of the gas lost is from u stompin it to hear the exhaust, that was my problem.

 

wont at all hurt ur gas mileage, but yeah when you step down on the gas more to hear it the WOT is to blame for the gas mileage drop

 

ROFL, YES!!!

I recently hacked off the muffler on the truck, it does cut your gas milege if you have a heavy foot. It freaking sounds NICE!!!!

 

Dropped my muffler in 2001, BEAUTIFUL sound, it rivaled Mustangs for the small block Ford rumble! I did not notice any dramatic drop in mileage or power, even when towing...I did, however, get three tickets in two days...It was fine for years, and then all of a sudden every cop in my county got rude about it...I say, GO FOR IT!

 

I've got a 02 supercrew, no muffler, straight from cat-back, sounds great, havent noticed any loss of mpg.