S4 Question

4th gear at 85 MPH with stock tires (stock for SR5) should put you around 3600 RPM's with the torque converter locked. Should be no problem at all. My 2020 does it easily.

 

Once again, if you slap your truck over to S4 at a normal speed, say 50mph, it should never shift to fifth or six gear. If your truck does, it isn’t working as designed and has a defect.

 

Contrary to popular belief, no where in the manual does it say to use S-mode for avoidance of overdrive while towing.

 

Section 4.1:

 

Read that closely and focus on "To maintain engine braking performance" and "when using engine braking". Also note the lack of the term "overdrive". I think the overdrive thing is a probably anachronism passed down through the ages.

Also check out the section specific to s-mode. It explains that the purpose of S-mode is for controlling engine braking force.

 

It won't. You'd need go about 70 mph in S4 before it would upshift. I've towed my boat going up the ramp onto the interstate in S4. Once you reach around 70 mph it will upshift.

 

Ok. What rpm are you at when this upshift happens? Tks.

 

What?!?

 

I get all my misinformation from TW threads. Now that I’ve learned S mode can upshift from S4 To S5 all on its own I’m gonna just start out in S1 and let her auto shift all the way to S6

 

Gen 3 Auto trans gear ratios:
2016 Tacoma: 3.91:1 gears, six-speed automatic
1st: 3.60:1
2nd: 2.09:1
3rd: 1.49:1
4th: 1.00:1
5th: 0.69:1
6th: 0.58:1
As you can see 5th and 6th gears are “overdrive” ratios as they are a higher ratio than the 1:1 ratio of 4th gear. Google overdrive for a detailed description if you are really bored.

 

Not me buddy Im runnin’ a 4.30 rear diff in my stock 2TR-FE automatic, smokin’ tires, burnin’ rubber from the getgo

 

To be fair, many years ago a well respected builder of racing transmissions told me that if you spun up the torque converter high enough an auto tranny would upshift regardless of gear selector position. That was back in the day of TH-350, Th-400 and Chrysler Torque-flites though, long before computer controls. I never tried it myself so I don't know for sure. Anyway I'm not quite ready to say it couldn't happen. Maybe the TW transmission guru @gearcruncher could shed some light on this?


I guess on my way home tonight I could put her in S2 or 3 and get up to highway speed and see if it shifts up, but I probably won't because, well, I really don't care.

Meanwhile that guy keeps insisting there is no S6 when he's been shown multiple times that there is.

 

I have never tried it while stomping the gas pedal, but I have had it in S2 or 3 on a downhill and the engine will really scream, at least until I chicken out and pulse the brakes to get the revs under control. I've never had it kick me out of a gear lock, though. And I'll tow in either 4 or 5 frequently, at highway speed.

 

Yeah it's a feature. There's a video on this on youtube. Shows that you have to do something pretty terrible to hurt these vehicles as there are many safety nets built in.

 

So, in the interest of science and despite what I said earlier on the way home tonight I got up to 60+ in S2 which was around 5500 rpm and held it there for a half mile or so. No upshift. FWIW.

 

Nice chart, got the top portion of it? I presume the top chart is upshift speed. I’m curious of the source as well!
I also don’t believe those speeds lol.

 

GTFO with actual tested facts, this is TW!
Actually thanks for taking one for the team and giving the evidence most knew but haven’t proven like you just did

 

2016 FSM...

 

good stuff, thanks!