S Mode & ECT Use for Mountain Driving

Just got a 2019 V6 Automatic & also just moved to the mountains. I’ve never used ECT or S Mode before & am a little hesitant. I read the manual but wanted to hear from others on this forum. My questions are:
1. How do I best use S Mode for going down steep hills (Specifically- can I move from D to S on the fly? Won’t it start at 4? If so, do I quickly downshift to 2 for a steep descent? Once at the bottom of the hill can I kick it back over to D or do I need to bump it up to 4 before doing that?)
2. Should I use ECT going up steep inclines? Can I just turn it on/off on the fly?
3. Back to S Mode - I’d only be using it bc I heard it helps with engine braking. But if there’s any risk to using it - I’d rather burn up brakes than damage my transmission - are there any potential risks or am I overthinking this?

 

Good questions I look forward to more experienced answers.


For the most part, assuming you are not doing 120 MPH I think slipping into S Mode on the down-hill-slide is going to be just fine.
And you can, assuming you are not doing 120 MPH I think slipping into ECT is fine... and yea turning on/off on the fly is ok as long as
well you know about the 120 MPH part.

 

I used to live in a town where the way out was a steep mountain. I just left my 2021 Auto in S4 and let'er eat. It helped going up and down. Just using ECT Power going down would let it shift into the overdrive gears and lock the torque converter so no engine braking. Sometimes following slow traffic or a semi going down the mountain I'd bump it in S3 or S2 to use less brakes.

 

You can use both on the fly, they’re designed to. Just play with them, you can’t really mess it up.

 

The nanny features in the computer will not let you downshift past what it feels is safe, so play with it all you want and see what works for you.

I use ECT every time I get in the truck as it helps with shift points and poor low RPM torque of these motors.

I use S mode every time I drive as well to either hold a gear longer or slow down faster.

 

I live at 8500ft and I drive 2000-4000ft of elevation regularly. I also drive an auto.

I just leave it in drive and send'er. There's no downside to using ECT -- and there is an always-on ECT mod -- or making use of engine braking but ultimately you're driving an automatic and it will handle going steep grades just fine. I would get a tune and not worry about ECT personally.

The exceptions are towing.

 

Forgive my ignorance- what’s the benefit or point of holding a gear longer? I’ve seen several threads mention they enjoy driving around town in S 4.

 

My 2016 has 70K miles on it now. I am up and down 4.000+ foot elevation changes on a regular basis.

I use the S mode to gear down on any hills I need it. Daily use of S mode. I am offroad 1-2 times per week and in 4-hi or 4-lo on most trips, and use S mode all day long as the roads are rough and lugging it up and down hills in D really bites.

I don’t know about smaller hills, but for me ECT never works when going up huge highway elevation changes. It has no impact omce the elevation and duration of climb are too much. So I just use D, or then S to drop into 3rd or 4th as needed to getup the hill.

Don’t use cruise up steep long elevation inclines. You will be moving along fine at 2500-3000 rpm, and cruise will suddenly decide it is time to slam it up to 5,500 rpm. Just use the pedal and ignore the cruise controls stupidity.

Cruise is great for long steep highway descents. I have one highway hill that is 23 miles long with a 5,000 foot drop and a 70mph limit. I can set cruise at 70mph, and never touch the brake once in that 23 mile descent. The cruise really effectively manages the downshift and braking.

I watch the other drivers constantly hitting their brakes, which on this hill in summer equates to “look that car is on fire on the side of the road.”

 

toyota put a good car motor into a half decent truck and didn’t change the cam profiles at all.

power comes in way late and is short lived.

holding a gear allows me to keep the truck in its power band to pass easier.

 

I see nothing wrong with this picture.

(Posted from the owner of an OTT tuned '22 6AT regeared to 5.29s.)

 

This is helpful. So in my case - I’d be leaving the park area and it almost immediately starts downhill for at least 2 miles - very steep and some switchbacks. If I kick it over to S it’ll be in S 4 to start. Do I then just click it down to S3 or S2 immediately or is S4 good to stay in? When moving from S4 to say S2, do I need to be actively moving and slowing down while changing? Or is it ok to bump from S4 straight to S2 going downhill?

It sounds like cruise control may be easier/best. So if I just kept it in D and did cruise control for 40 going down this hill, it would automatically engine brake for me? I guess if I need to tap the brakes though it’d cancel cruise control.

Disappointing about ECT as I had read it may be good for big hills. Womp Womp.

 

I really think you're overthinking this. You're driving an automatic not a manual. Let the automatic transmission do its job. There's some folks on TW that will min-max their RPM for nothing more than fun and because they hate the sound of the spinnin' but it's really not doing any harm to just let it figure it out. Especially downhill. If the grade isn't steep enough that you should be in 4LO for compression braking, let the automatic be an automatic.

 

I’m sure I am. I just read several things to use that mode on steep hills. And now I’m finally around some and I want to take good care of this truck. But yeah - it almost seems gimmicky. My last vehicle was a 2019 Honda Fit. It automatically engine braked, I didn’t have to do anything. It had a CVT though.

 

I want to be clear that there's legitimate reasons to drive in S with ECT on and that reason is towing: there's no "tow mode" where you tell the automatic transmission to adjust it's shifts and the closest we have is ECT+S. It's important there because the ECU isn't tuned for the extra weight and the "its an automatic, let it be an automatic" argument falls over.

But I really think that if you aren't towing and if the hill you're gong up or down doesn't call for 4LO, just let the automatic figure it out.

 

When i had my 2016 TRD OR and would get up in the mountains, having the truck in s4 and ECT on became instinctive in a way. Being able to lock out the overdrive gears was really nice to alleviate some of the shifting and let the 3.5 work in the upper RPM's both up and down hill.

Even in my GX 470 i own now i will pull it out of D and down into 4th or 3rd to alleviate shifting back and forth and use engine braking on steep down hills.

 

WAAAAYYYY overthinking this!
OP, just get your new truck, find some less aggressive terrain (hills, turns, etc) and drive around town and try the S mode, you will have the hang of it 3 miles.

 

I think you may be interpreting the S mode a little incorrectly. S mode is kind of like giving the transmission a limit and a suggestion. S4 means it won't go into the overdrive gears but it can still be in 1-3 when it chooses. Going down in the numbers means you are giving it advice to go down and it decides to follow you in most cases! Switching over to S mode does not mean you are immediately in fourth gear.

 

I can give it a go. Just trying to avoid burning up my brakes. But I see what you’re saying!

 

ECT mode is Tow/haul mode. just a different name. i think it unlocks the torque converter to give more torque in some gears.