[trooper Tdiesel]

my diesel SUV is much older 1986 and has a much different power band from a modern diesel.

so this may or may not apply to your auto?????

for me rpms, gearing and load is a major facter in what speeds and loads get good or bad mpg, im 60hp at 3,000 rpms max hp is 80 at 4,200rpms and 125 torque at 2,200rpms in a 4,300lb auto. so yea im slower then dirt
other then that i have more limits being a older auto, i have next to no boost under 2,200rpms. so at times, down shifting to get rpms just above 2,200 and backing out of the throttle will get better mpg then trying to use the next higher gear at WOT with no boost, on a up grade.
where other times using high gear on a flat road at a steady speed way under the 2,200 mark gets better mpg.


also, ive found with the trailer in tow, i have no idea if you pull any trailer.
driving 100% as a 4speed trans can net better mpg for as long as i keep my rpms reasonable.