My 2500 HO is stifled sounding from the tail pipe end at idle. I can only imagine what that is at speed, and under load. It has that sssssssshhhhhHHHH sound. It's bone stock.<br><br>I've done plenty of 'gassers' in my day, 30 years shade tree, a 71 Road Runner w/440, 91 Mustang GT, 2001 Nissan S/C, Camaro Z28 2002... Big exhaust and headers on those machines gave me 10-25% mpg and performance, not to mention wood at the sound (haha).<br><br>Does this same logic work on diesels (this 03 is my first)? I don't want to end up with a drone noise, I'm an old fart (48) and can't put up with the hypnosis, as I pull for hours on end at times, but I'd like to open her up some if the mpg would increase, even with a bit of extra noise. I've spotted 4&quot; and 5&quot; exhaust and wonder if its worth the price? Maybe just the stock muffler needs replacing. Your opinions, warriors.

 

If you have a 2003 CTD you already have a 4&quot; exhaust. It was increased over the 2002. Buy some jivin CDs and listen, you won't fall asleep while driving.

 

Just get rid of that muffler and the engine will be much happier. Jeff

 

exhaust comes out trbo at 4 inch,then promptly restricts down to 3 1/2 where it travels thru a very restrctive offset muff then to a 4 inch tailpipe.

as soon as i get a downpipe, my 03 will have a 4inch straightpipe ;D

 

Is that legal??

 

darn right<br><br>the turbo is a noise reduction device

 

I guess I'll be visiting the exhaust shop soon ;D

 

how much louder will it be?<br>comparable to pre'03? in between?

 

should be a little deeper in tone but noise level will be the same as prior years trucks with all that silly stuff after the turbo removed.<br>Jeff