Questions on S mode and Towing

I plan on getting a 16ft boat for the lake and a small utility trailer for hauling yard debris. I’m looking at a boat setup that should be no more then 2500-2800lbs fully loaded.


I understand that S mode is Sequential mode, acts as a gear limiter and per my manual I should not be in 6th gear when towing. I am wondering if I should also stay out of 5th gear when towing as well? Isn’t it also an overdrive gear?


If I set S mode to top out in 4th and I’m doing 50-55mph am I doing anything bad to the truck? I imagine it’s probably fine as long as im not revving at super high Rpms.


Hope this doesn’t sound dumb I’m just new to doing any towing and want to make sure I take care of my trucks engine as best as I can.

 

I tow my 15' in S5 mode...never a problem. Actually, I do 95% of my driving in S5, and rarely use 6th.

 

4th is direct-drive (1:1) and 5th and 6th are both overdrives. I have a 2.7 and put it in 4th in hilly terrain so it is not shifting all the time. It's not super wound up in 4th, kind of like an older 5-speed/4-cylinder car that turns 3000-3500 RPM on the highway.

 

I tow a 5000lb GVWR (i.e. I likely am not actually at 5000lbs but that's the trailer rating) travel trailer and regularly drive at 65-70mph in S4 with ECT on without any concern. You're not going to hurt your engine at those RPMS (2300-2800ish) for extended periods of time.

I also tow in S5 more frequently now as I've become more confident in the truck. If it's particularly hilly, I'll pop it back into S4 just to keep the transmission from being confused or the torque converter having to engage and disengage frequently.

Longer or steeper hills I'll drop it to S3 and run the entire hill at 3500-4500 RPM. Again, no real concern. The engine hardly makes power until 3500 RPM anyway.

You'll be fine towing your boat at whatever speed you're most comfortable with.

If we buy Toyotas because we trust their reliability and engineering and we use them within their advertised specifications and per their user manuals, we really shouldn't have to worry about them breaking within those limits. That's my philosophy anyway...

 

Great info and addresses a lot of my concerns. Thanks!

 

Think of as a manual transmission without a clutch. Drive it by feel and if you sense more power is needed downshift accordingly. It is better to be in a lower gear than you think you need, and to downshift manually before the truck starts to strain.

2800 lbs isn't all that much and you probably won't need to go too low. Maybe if you are in some steep hills.

 

No problem at all.

It's really easy to get analysis paralysis when it comes to towing and there is a TON of subjectivity in regards to the topic. I've read countless anecdotes of people dumping trucks such as ours and moving into 1/2 or even 3/4 ton trucks just because they don't like hearing the engine purr above 1800 RPMs. At some point along the very wide spectrum of trailer sizes, yes, you need to upgrade your truck. But ultimately, the Tacoma is pretty capable if you adjust the way you drive and if you're willing to put up with a little high RPM engine noise on some rare occasions. Ultimately, high RPM doesn't objectively mean engine damage. Hell, some engines degrade faster by not running them at full bore with much frequency (my brief ownership of a Mustang GT350 was one of those engines).

There's lots of "you shouldn't do that with a Tacoma" opinions but I've yet to see a single post pop up on this forum of "I blew up my engine/transmission while towing within specification." This generation is now seven years old at this point. I think that speaks volumes for this little V6 and the rest of the truck.

BUT

Subjectivity is still important for an individual. If you don't feel comfortable pulling a certain weight or going a certain speed or going around a turn or braking performance or any other uncomfortable feeling while towing, you should do what you feel is necessary to make you feel safe. Or hell, if you just think it sucks not having enough room for your gear or that the ride is uncomfortable while towing, that's certainly a good enough reason to upsize.

But the main point is: the Tacoma can handle a lot of shit. You just have to be realistic about what you're comfortable dealing with.

Final thought after a few years of towing a couple travel trailers: aerodynamics plays a much bigger part in engine demand and performance with similarly "sized" trailers than their weights in some cases. My current trailer nets me 2mpg more while towing than the previous one, even though they were basically the same size. My current one is much more aerodynamic though.

 

Despite widespread belief, the manual does not say to never use D while towing. It says that you should use S5 or lower when engine braking while towing. Read it carefully and also understand that the purpose of s-mode is engine braking.

If you don’t know what engine braking is, it is the driving technique of using the friction in the engine (e.g. pumping losses) to slow you rather than the brakes. This can save on brake wear and prevent brake overheating during long descents. It’s also useful in low traction descents to maintain control of the vehicle.

You can use s-mode for other things if it pleases you, but understand that Toyota has not directed you to.

EDIT: s-mode while engine braking also keeps your alternator kicking out the juice due to the higher rpm, which might be important if your trailer has a big power draw.

 

Thank you for the thoughtful and detailed responses. I feel like these really are very capable trucks and a decent chunk of the equation is just learning how the truck wants to be driven and figuring out how to make the features it has work for your desired benefit. Of course there may come a point where sizing up to a bigger truck makes sense but these trucks seem like they can do a lot if you just put a little thought into it.

 

Thank you for the info. I feel like I’m getting a better idea of how this all works and appreciate the breakdown.

 

To sort of sum up what the manual is saying… if you are towing something heavy down a mountain, do not ride the brakes in D. Shift into s-mode and pick a gear that minimizes brake use while maintaining a reasonable rpm.

So few people seem to understand engine braking and the purpose of s-mode.

The Toyota manual could be a lot clearer on this subject.

 

Okay, so if I’m just cruising down the highway pulling my boat I may not need to be in S mode at all? I thought I had read some forums advising against towing in D at all but maybe that’s expecting varying terrain with climbs/descents and trying to be prepared to use the engine braking and staying out of 6th.

 

There are a zillion posts saying you will destroy your transmission by towing in D (or overdrive), but there is no scientific evidence of this that I am aware of. I’ve wondered if this was a valid thing in the past when overdrive was a device separate from the transmission.

 

That said, if you don’t enjoy your automatic transmission shifting for you (as it was designed to), use s-mode or (better) trade it in for a manual transmission.

 

I would just leave it in S5 and manually shift if. If you go to S from D, it automatically goes to S4 then you have to upshift. I don’t like that personally and leave it in S and shift accordingly to terrain.

 

The S4 default is great for, you guessed it, engine braking. Neither S6 or S5 will slow you down much at typical hiway speeds

 

That's what ECT is for. Set it and forget it for that load.

 

@Kidlin you have gotten some great advice from everyone here and I agree with them all. Have towed a 4,700lb travel trailer some 5k miles this year and the taco has done it all awesomely, even up to nearly 11,000ft.

One thing is if your trailers have brakes you should definitely get a brake controller, Redarc brake controller for sure, looks oem, doesn’t get in the way and does what it’s supposed to.

Just to add to the poll I tow is S5, no ECT and drop it to 4th if the torque converter is getting too warm on the Hwy.

 

I believe they changed the user manual from 2020 onwards.

One thing to bare in mind is that you can heat the torque converter/transmission oil up very quickly driving in 5th without the tc locked. I wasn’t paying attention and I noticed the trans oil had gotten up to 240 degrees cruising in 5th. If I had ECT on then it probably would have downshifted to 4th earlier…

Soooo…. D or S5 and ECT on and you will be fine

 

Good info here... so for this beast of a 1200 pound load... plus another 200-300 in the truck bed you say S5 + ECT ??
Heading to the hills on Thursday if I don't get burned out.