Tow Haul Mode- Overdrive

[retired_engineer]

Not quite related but on the topic of speed as this thread has turned into... I recall on one trip south years ago we drove through (in our Motorhome) a city, that had signs for trucks to use the center lane on a three lane highway - for the life of me I cannot recall where it was and have never seen it again anywhere. At the time, I thought it was ingenious because forcing them into the right lane with all the merging traffic is a nuisance and a hazard. I always thought that would be a better way for all cities to do it. Trucks go in the center at their speed, the faster vehicles go in the left, and the nimble vehicles can handle the merging traffic. I thought that was a great concept.

Years ago I ran into signs for trucks to use left lanes through Wyoming or maybe it was Nebraska. When I questioned it I was told it was done there to even out lane wear and increase the time between repavings.

[RV2600RB]

Towing 80 plus looking for trouble in a hurry.

^^^ I agree. Yikes.

[RV2600RB]

In an effort to get this thread back on track, I use drive and tow/haul and cruise control when towing. I don’t use cruise control in the mountains. I use the exhaust brake on full going down mountains.
I tow 65-67mph because that’s the max torque rpm for my truck, which is also best mpg (unless the limit is less).
It all comes down to your rig and comfort level when towing.
Only you can figure that out.
Rich

[Maddgopher]

In our current truck (diesel and Allison 10 speed) I put in Tow/Haul mode, turn on exhaust brake, run in "D" and set the cruise and let the truck do it's thing. The systems are linked and all work together. I get about 10.5-11.5 mpg and our trailer weighs about 8k, loaded.
On my 1/2 ton 5.3 gasser with 6L80 tranny, I would run manual shift and in 5th gear (no over drive) and not set the cruise unless my drive was relatively flat. Burns more fuel but saves the tranny from having to hunt for the right gear all the time.