Hello, to you all....
Been a while.
So I have a 1997 Thomas 8.3 Cummins Allison 6 speed 6th is still locked.
I did 2 Trips in it of 350-450 miles last summer got an average of 11.5 mpg...
Pulling the Oregon Passes From Willamette Valley over to the East, it would only do 15-25 mph up the grades in 2-3rd gears.
We tweaked the Rail on the P-Pump after the last trip....I just did 1400 miles over to East Idaho and Back to recover a Car and Trailer....( different story there )
Bus hit the Passes and Never came down below 45 mph....I was Passing Semi's....
Also Stayed in 5th till near 45 mph, then dropped to 4th....Heat was Good, all things looked good
BUT it only got 6.5 mpg loaded or empty....lol
I was trying to average 60-65 mph the entire trip and it was running at 22-2500 rpm....
Curious as to what you guys are Running for averages...?
My dodge Truck with 5.9 24v cummins runs 72-77mph at 1900 rpm based on load and Climb on the hwy....
Does this 8.3 Rev limit out..? if so at what RPMs...? range
and What is the Happy range for Fuel economy , power, torque...?
Thanks Guys
John