'04 2500 Exhaust Diameter

[XTOAK]

I've been noticing that the diameter of the exhaust outlet at the back of my truck is smaller than those on the 2500HD...all have the 6.0L engine but different exhaust outlets...could this be what affects mileage giving some better and others worse? Any thoughts?

[sonjaab]

X.............I noticed that a few years back when I got a 01 2500LD and my bud got a 2500 HD.

 

His exaust pipe was a bigger diameter and routed different than my LD. The muffler was larger also..................geo

[gave20]

I think most LD's and HD's are fairly close in MPG. The trucks boast the same HP and TQ so I imagine the HD's have a more resticted muffler to compensate for the larger tailpipe.