I just traded in my 1992 Dodge diesel for a new 2006 SLT Quad cab 4x2
dually long bed with the automatic transmission, 3.73 axle, exhaust
brake and towing package. The 92 was a pickup truck, this new one is
pretty luxurious for a truck. The 92 Cummins had another 100k or so
left in it, I'm sure, but the rest of the truck was showing its age.
Rattles and squeaks, all the window rubber was shot,  but for a 14
year old truck with over 200k it held up very well with no major
problems.

My 92 averaged about 18.6 mpg empty and around 15 towing.  Any idea
what I can expect with this one?  Empty I usually cruse the speed
limit, or 70 max and towing 60 to 65 max except California where it is
55

I will probably have around 500 miles on it when I will pull a 7000 lb
trailer to Oregon.  I assume with only 500 miles that I shouldn't set
the cruse control and just go along for hours at one speed.  Although
the first 250 miles of the trip will be back roads through small towns
to reach the interstate so that should help.

While in Oregon or California I plan to buy a 5th wheel that will be
at about 85-90% of the trucks capacity and that I suspect will be a
big hit on mileage.

So any hints, tips, things to watch out for would be greatly
appreciated.

Thanks,
Jerry