at what rpm should engine run at 55mph out of tow/haul mode

okay...which transmission and what country? hills? lots o braking...like flagstaff to phoenix?

rely on the automatic transmission for when we should "kick-down"...if climbin' a hill and passing a guy too, you could select the next selector down 5speed...select4 etc...bringing the rpm's up....if you're downshifting with a load probably would rather a manual transmission....I'd say 34,000 rpm to answer your question~

My God, Roy, this is not a jet engine. 34,000 RPMs? Did your fat fingers touch the 4 and 3 at the same time?

This is my answer on your other entry: It depends on the gear ratio of the rear end. Put the transmission in tow mode and see what the RPMs are at 55 mph. Take it out of tow mode and now see if the RPMs have dropped. If the RPMs have not dropped, that may be the problem. Since 55 mph is around the normal highway driving speed, I would guess the engine should be turning at or near the 1800 to 2200 RPM range. The 70s trucks would turn around 3000 to 3500 RPM range due to the rear end and transmission gearing.

you're right carson forgot the dash 3-4000 but you nailed this already...nuff said~

ouch! agree with Carson 1000% on all...