S4 mode

Help me out. My son drove my 2016 Tundra in S4 mode for about an hour yesterday. Speeds ranged between 55/70mph. I was in the passenger seat and happened to notice the RPMs were sitting around 3k. That’s when I realized he was in S4 not drive. Anything to be concerned about with transmission? Temp seemed normal and no warning lights came on. Thanks.

 

Nothing except mpgs taking a bit of a hit. The trans will run cooler than in D due to a locked up 4th gear no overdrive to cause slippage or excess heat. Its as if you were Towing yet were not.

 

Completely fine and as mentioned it’s designed for it when towing.

 

That’s the best gear to drive in, don’t worry.

 

He's not getting his beer tonight!

 

Thanks for the replies. The MPGs definitely took a hit. Thanks again.

 

You're totally fine. All that did was prevent the transmission from shifting to a gear higher than 4th. It'll still run up and down the gears below that like normal, and you can do 80 MPH in 4th if you need to.

 

It’s fine. Just burned a little extra fuel.

 

I have been driving in S4 around town (under 45 mph) for many years and have 102,000 miles on the original transmission. 2 dealer flushes so far and it still shifts like new. I prefer the better throttle responses and the trans not shifting constantly and lugging itself. I’ll bump it up to S5 when on the highway and S6 on the highway when it’s level or downhill.

 

I use s mode often, just choose the gear based on speed I am traveling. Seem to get better MPG as the engine does not lug or want to downshift as much as it does in auto.

 

What about driving in Tow Haul mode all the time just for the extra boost?
I've read comments on here before that someone does that regularly. I'm guessing you wouldn't want to drive at really high speeds in Tow Haul, is that correct?

 

Nothing wrong I only drive in s4 and s5

 

I drive in S4 for 1600 miles a year dragging an 8000 lbs trailer. It likes 3krpms.

 

It's a Tundra so "really high speeds" is relative, but there are zero mechanical issues driving every day, all the time with Tow Haul mode on or in S4.

The 5.7 needs higher RPMs for power. It is fine running at 3000 rpms all day. The only negative is you can watch your fuel gauge drop in real time.

 

Tow haul just changes the shift logic and sensitivity of the pedal. There's not any kind of "boost" or anything that can hurt it anymore than spirited driving.

 

I use T/H all the time. With the button pushed the maintenance light comes on at 5000 miles, which is when I do oil changes.