Tow in tow haul/d or s mode

Hi! I am new to tundras.com. I recently bought a new 2020 tundra crewmax platinum. I just got back from a trip pulling my 2019 airstream 22 sport to Cincinnati Ohio area from northern Ohio. This was my first time using the Tundra to pull my trailer. I used a 2004 Toyota 4Runner sport for the past couple years to pull our trailer Which has done well but I wanted something with a little more power.We would put the 4Runner in 4th gear so it wouldn’t keep shifting into overdrive(5th) so we wouldn’t overwork the transmission. With the new tundra we pulled in the Tow haul mode and left it in drive. It pulled just fine but it seemed that when I Was hitting some hills it would lose some speed and I would have to give it a little gas so it would down shift to get back up to speed. I was wondering If I should keep towing like this or put it in S mode shift to 4th or 5th and tow haul? What setting is best to pull a 4000/4500 pound camper? We plan on pulling in hills sometimes so I don’t know if different surfaces( flat or hilly) matter also.would like plenty of input on this. Thanks

 

https://www.tundras.com/threads/s-vs-d-and-tow-haul-switch.68253/

 

Lots of info on this as noted in the link provided by other responder. But I add my 2 cents since I recently purchased a 2020 Bambi 20’ (weight 4300 lb with full freshwater and hot water tanks and about 50 pounds of stuff) and Tundra SR5 Upgrade (38 gal tank) TRD OR 4x4 with Tow Package and Blue Ox SwayPro WD Hitch and made my first 3 day trip. Based on all advice I read on here beforehand I used Tow/Haul, S4 as starter and then S5 on open relatively level stretches which seemed to maintain RPM just under 2000. Good gas mileage, relatively speaking, at around 12 mpg. I think it is the low weight around 4000-4500 lb vs the Tundra’s stated max trailer weight of 9600 lb that allows the truck to run in S5 without transmission cycling when not climbing hills. BTW, this was towing in NC from Raleigh down to NC/SC coast and back.

 

Smstoyloy I agree. From what I have read I will more than likely go with s5 in my area that is relatively flat and since I only pull around 4000 with my gear in the trailer. We usually pack light. And pull in s4 in the more hilly areas when we head south. Airstreams seem so easy to pull with being light and aerodynamic. Definitely nice! Thx for input

 

Thumbs up on using S5, My truck lives in S4 towing 3K on 35's.