what is the better exaust 4" or 5"

 

Unless you are running major HP neither one will make a difference. I think the sound will make you smile

 

5"

 

5" on the 3rd gen's has been rumored to help in the egt department.

Matt

 

and it sounds good too....

if you go to the dieseldynamics website, you can listen/see video clip of their 4" exhaust and 5" exhaust. i think the 5" one sounded better...

 

the 5 is nice but if you pull trailers on long trips
at 70mph there is a nasty drone

 

i've got bd's 5" on my truck, and i don't have any drone at 70mph [although i don't drive that quick usually]

i do have a little drone at like 1100rpm in 6th gear very lightly loaded, but it doesn't bother me. [i did use band clamps instead of the crimp clamps that came in the kit - maybe that's why?]

 

Im sure each brand is a little different as well
mine is a head killer at heavy load @70mph

 

mine was a head killer at 2500rpm... I added lots of sound deadener and added some mass to the exhaust, and it's all gravy now