Has anyone added a free flow muffler such as the Magnaflow to their stock exhaust. Did you notice any diference in MPG or temp etc... how was the sound.

I replaced the one on my last truck an 04 8.1. The sound was killer but did not notice any other dif in it. Thanks Ed

I can tell you now that it wont' be as loud as an 8.1.. the LLY's are surprisingly quiet compared to gassers and the previous LB7. There are several that have just a cat back installed on here that will chime in soon

Has anyone added a free flow muffler such as the Magnaflow to their stock exhaust. Did you notice any diference in MPG or temp etc... how was the sound.

I replaced the one on my last truck an 04 8.1. The sound was killer but did not notice any other dif in it. Thanks Ed

Yes, I have (Magnaflow). Not much difference in sound if you keep the cat, a little better tone, especially when you let off or truck downshifts when in tow/haul mode. As for mileage, may have added 1-1.5 mpg, not sure since truck is so new and the mileage increase could be associated with break-in more than the muffler change.

I have the turbo-back magnaflow, love it! Non-intrusive tone. Only slightly louder than stock, and then only when foot in it. Otherwise quiet, like it should be. I was impressed, for a straight thru.

I had a Flowmaster on my 02 first. It was good & sounded good. Only set me back $200 bucks and that counted the install. Then one day I said this is a diesel why am I running a muffler. So I straight piped it. 4" all the way out. I like it better with the straight pipe. If you want to hear some of the mufflers most of the big companies have sound bites that let you hear what they would sound like. LOL

If you are looking to replace the muffler only, I would first consider running no muffler - you can't get much free'er flowing than that. I just had the muffler on my '05 taken off and replaced with a piece of exhaust pipe. I was very suprised at how quiet it still is. At idle and just above, it is barely louder than stock; above that, it still sounds stock to me.
I hope I'm not steering you in the wrong direction (this is my first diesel), but just something to consider.
Brian
BTW it cost me $35 at the muffler shop to get it done.

If you are looking to replace the muffler only, I would first consider running no muffler - you can't get much free'er flowing than that. I just had the muffler on my '05 taken off and replaced with a piece of exhaust pipe. I was very suprised at how quiet it still is. At idle and just above, it is barely louder than stock; above that, it still sounds stock to me.
I hope I'm not steering you in the wrong direction (this is my first diesel), but just something to consider.
Brian
BTW it cost me $35 at the muffler shop to get it done.

BrianB:

What about drone?? Also, is it very loud when you "hammer it" towing a load??

I have the turbo back system with the 37 inch muffler which is 13 inches longer than the one you are talking about, I have an 03 with the system you are asking about and it is loud as hell but that truck gets 3 mpg more than my 05. On the 05 there is no difference over stock other than the look of the 4 inch tip coming out of the back. I saw no increase in MPG but the system looks nice.

BrianB:

What about drone?? Also, is it very loud when you "hammer it" towing a load??I haven't noticed any drone and I have not towed anything with it on yet. I rolled the passenger side window down and floored it while driving next to some concrete Jersey Barrier; I could hardly notice any difference.
Brian

Thanks BrianB