Cummins engines - particular the 12-valve - are great fovorites for hot-rodding becuase that lawn-sprikler injection system can easily be made to pass enough fuel for lots of HP. That and they are very compact and easy on the mechanic.
As for being more efficient - t'ain't so.
I pulled same load with a 91 dodge with 10' cube and a 00 PSD CC 4x4. The ford got consistently 2-3mpg worse towing the same 13k lbs.
The thing about the 12valve dodge is the mechanical injection. There's no computers or sensors that die and leave you stranded. Our 95 PSD is awful to work on. The glow plug system is a battery killing machine. The PSD is also way more trouble prone, not to mention the ridiculous cost of the injectors. I also don't like the need to have a special scanner to work on the PSD. My old 12valve dodge was great. It required only basic maintenance. They all have there foibles but I find the old cummins to be less annoying to live with.
02 Saturn SL
for pics click the link below
Big Dave, comparing your truck to any other is not an straight up comparo. Given a PSD and Cummins in identically prepped trucks, what would the outcome be? I don't know myself and I am certainly too lazy to find out!
My 01 4x4 Dodge/Cummins has all the wrong mods for fuel economy. Lift, bigger tires, Edge Juice, etc. yet if I get a strictly highway run at 55 it will usually get 15 mpg empty. I don't see any reason I could not take a 2x4 with similar mods as yours and pull the same mpg's you see.
My personal best on the truck was an honest 23mpg. Almost all down hill with a huge tail wind! Wish I could repeat that.
Love what you are doing to your truck. Keep trying to prove us wrong!
Thanks for the pointer to the Diesel Power Mag article. I found it very informative. Not anywhere in the article did they say anything about going only 40mph.
"In follow-up testing (to see if the figure was a fluke), the truck still averaged 26 mpg at speeds ranging from 70-80 mph with just the tires aired up and the grille blocked off, making our 31-mpg number seem believable"