Towing 20' pontoon boat

2017 SR5 4.6 without tow feature. Has anyone ever added a trailer tow program to their transmission. At 60 to 65 mph when I go up an overpass on the interstate the trannie wants to downshift to 3rd. The boat weighs in under 2000 # , however the wind resistance is horrible.
Any thoughts or guidance would be greatly appreciated.
Thanks,
.Catflattner

 

Are you towing in "D"? You should at least tow in "S4" in the hills and "S5" on the flats. IMO

 

If your truck doesn't have a Tow/Haul button it's not a plug and play thing that you can add. Reference details here: https://www.tundras.com/threads/adding-tow-haul-switch-to-4-6-sr.4877/

Your best option is to add a Pedal Commander adjusts changes throttle sensitivity, therefore influencing a change to shift points.

 

Nothing wrong with a downshift and rev over a hill. Its shifting for a reason - it wants the power.

 

Ya I would but it in S4, and if it continuously wants to down shift to 3rd I would probably slow down and ether leave it in 3rd or slow down enough it doesn't keep wanting to downshift. I know it's no fun but 55 vs 65 can make a huge difference in the power required to tow something. And I definitely would not want my truck to keep shifting from 4th to 3rd the whole trip.

Also probably common sense but make sure all seats are folded down and tops are put down in the boat to help reduce wind resistance!

 

Bullydog gt tuner you may have to call them to see if they have a tow tune for your truck they do for the 5.7 just not sure about the 4.6

 

Thanks to all for the replies. I'm afraid I'll keep doing like I have done in the past. Shift to S4 , run 55 mph , grit my teeth when it downshifts to 3rd and get 9 mpg.

 

There is nothing wrong with allowing your transmission to shift like it was designed to. It's a little nerve racking when the engine revs, but these engines like to rev, it's not hurting it. The only think I would be concerned with is if it was constantly shifting, other than that, put it in drive and go.