Tow Setting Questions

Hello everyone
Just for the record im a 100% noob with trucks but not to cars!
(Probably stupid questions but how else am I gonna learn)

When using the Tow Haul is there a certain weight that needs to required for you to use this? Like if you tow something under 1000 pounds is it necessary? I only ask this because im trying to get the best MPG possible and I want to know how our ECU works.

Also couldn't you just drive with S mode all day to get the best MPG? Because doesn't the ECU lower the the limit of RPM or something? Does our ECU learn our patterns over time so isnt it best to train it with S mode for awhile?

I ask weird questions.....

 

I was dragging my 16ft landscape trailer around yesterday (1500lbs empty) and tried tow/haul out of curiosity.
I think its way too froggy with tow/haul on.
Honestly... you can barely tell the trailer is behind you without T/H anyway... and im even on 35" tires.

I imagine its more usefull with trailers 4000lbs and up.

 

You don't have to be in t/h mode, if your only carrying 1000 or less you'll be fine. Definitely won't improve mpg. It changes shift points and stays in gears longer. Only way to improve mileage is drive like an old woman. But not really worth the couple of mpg you'll get. You bought the wrong truck if mileage is your highest priority. Just drive it the way you want to drive it. Couple mpg isn't gonna make much difference.

 

I don’t think S mode does anything except limit the highest gear the transmission will shift to. For example if you’re in S-4, the transmission and motor will run as they always do, but the transmission will not shift to 5th or 6th gear. You can use tow/haul mode any time. I use it in town all the time, not towing or hauling anything because I like the increased throttle response. What Tundra did you buy? Please give us some details and a couple of pics if possible.

 

I don't think a trailer under 1000 pounds count. Basically same as loading people into the truck.

Normally when towing want the rpm's higher than normal so the transmission has fluid flowing to keep the trans cool and to not lug the engine. But now that Toyota no longer cares about trans temp and it is almost impossible to lug the 5.7, I don't think it much matters.