Tow Haul Mode

[Different Drummer]

Anyone know if tow haul has any influence on systems other than the transmission? More specifically the Active grill shutters?
Been much discussion about running temperatures for the transmission and the engine as well.
I had a 40 mile drive on a fairly decent secondary road a couple of days ago. 55 mph speed limit.
Just the truck with maybe 400 pounds of sand in the bed for traction ( 2WD ). Nothing in tow.
I decided to run it in tow haul just as an experiment. In my truck I know tow haul locks out 8th gear. It does not lock out 7th gear. I used cruise control and let the truck do it's thing.
Oil, engine coolant and transmission Temps. stabilized and showed very little fluctuation over the entire distance. What I found interesting is that all the Temps. were lower than what from past experience I was used to seeing. So, is it possible that the active grill shutters are placed into an open position when tow haul is employed? I believe that my engine coolant thermostat is 203*F. Is that correct?

 

[Billet Bee]

the only difference I can speak to while using tow haul is that the engine break is much more aggressive

 

[Wild one]

View attachment 234028 Anyone know if tow haul has any influence on systems other than the transmission? More specifically the Active grill shutters?
Been much discussion about running temperatures for the transmission and the engine as well.
I had a 40 mile drive on a fairly decent secondary road a couple of days ago. 55 mph speed limit.
Just the truck with maybe 400 pounds of sand in the bed for traction ( 2WD ). Nothing in tow.
I decided to run it in tow haul just as an experiment. In my truck I know tow haul locks out 8th gear. It does not lock out 7th gear. I used cruise control and let the truck do it's thing.
Oil, engine coolant and transmission Temps. stabilized and showed very little fluctuation over the entire distance. What I found interesting is that all the Temps. were lower than what from past experience I was used to seeing. So, is it possible that the active grill shutters are placed into an open position when tow haul is employed? I believe that my engine coolant thermostat is 203*F. Is that correct?

The V6 version of the transmission must have slightly differant programming then the V8 version,as my 8HP70 shifts into 8th even with tow/haul engaged. Can't comment on the shutters though,mine have been deleted for years.