I drive an Isuzu NQR daily. I've eyeballed it as I fuel it almost daily--about 11-12 mpg in a mix of city/freeway. 5.2 4 cylinder oil burner, 6 speed auto. Would run to redline in 6th easily. (80+ mph) Has all the smog stuff, but of the three, one with 125k, one with 50k and another with almost 50k, no down time for anything mechanical. Almost all the down time was due to accidents. OEM tires were good for over 100k on the one truck--in the back.

Ride? Not smooth. Cabs are cheapo plastic trim. Seats good, radio good, air good.

Tons of them around, along with cousin Fuso and orphan Sterlings pretty much all in the same flavor. We have a bunch of Sterlings but not at my location. No one complains about them afaik, but they are an orphan.

I checked a 460 powered walk-in a few times. 7 to 8 mpg. My dad's '58 F600 292 4/2 would get 4 to 8 mpg. Cain't be helped, gas motor in a truck will bleed you dry on fuel.

fwiw.....