I tow ~9k lbs travel trailer. For the first 5k miles, I just put it in tow/haul and let the truck do its thing. Then, I started locking out 9 and 10. There is a DRAMATIC reduction in DEF usage (like half) not letting it shift to 9/10. That and being a bit louder in the cab is the only difference I noticed. About 8k miles towing like this now. I have 3.31 gears and tend to set the cruise at 65mph when towing on the highway.

 

If you feel satisfied with the factory programing of the automatic transmission, then there is no need to do anything but put it in drive and go about your business.

I dont know what you personally tow, but many of us that tow higher weights find there is much more control over the truck by driving in manual mode and or locking out the upper gears to avoid unnecessary shifts. You most likely dont understand it because you have not been in a situation where it would benefit you.

 

Agree 100%. It's more about driver preferences and the situation.

 

It seems that locking out 9/10 may decrease DEF usage, but it increases diesel usage. To me, DEF usage is less expensive than diesel. The counter argument to that is that you may be increasing the exhaust temperatures enough that passive regens are taking place, which may allow you to go longer between active regens.

I don't exceed 70 MPH when towing. Conditions often cause me to lower my speed.

 

Good discussion. I'm looking forward using the newer tech with my 22 6.7L on order coming out of my old 05 6.0L. I used to pull the boat behind my 5th wheel pulling 12K but sold the camper for good and now only pull 5K. One little trick I have always done is when on cruise control I will feather accelerator before going up hill and seems to cut down a bunch of shifting.

More importantly, I want to see a picture of your boat

My 2011 Supra 22SSV Worlds Edition

2015 Moomba LSV w/6.2L

 

A 6 speed gasser is much more enjoyable locking into 5th in the hills and letting off the accelerator some going up steeper hills. It just takes a little skill. Otherwise you’re jumping all over 4th-6th constantly, even down to 3rd if you are hard headed enough to stay at a constant speed.

On a 6 speed 6.7 with taller tires its much much better to lock it in 3rd around town when towing heavy. Much much more control accelerating and braking.

Usually around the max rated tow capacity. Thats my experiences and maybe you haven’t been in those situations.

Just depends on how you use it. Dont want some worn *** truck or have to check my straps every fill up because I’ve been yanking it through all the gears for hours on end.


As far as my 6.7 10speed dually it has plenty of gear, short tires, and dang thing has so much power it hardly downshifts unless you want to accelerate. Maybe a little different experience if you have tall tires or 3.31s though.

 

Wow, that is a setup!!! Here is my current set up with my 2014 F150 5.0L.

 

Very nice setup as well. Looks like a lot of room up front....

 

Yeah, or use a bicycle.

 

i love auto climate.

Totally different function. The locking out of gears keeps the transmission from going into overdrives when there are hills just ahead, and for the rest of the drive, that the truck does not know is coming, but the driver with intellect can and does know they are up ahead. So instead of letting the truck tranny shift into a taller gear and then lose speed quickly when it hits the start of the hill and then downshift and rev up to overcome the speed loss, ....and then do this over and over again in hilly terrain, the driver can just lock out the tall gears that will be OF NO USE in the miles of hilly terrain that lie ahead and avoid slowing down at all.

You really couldn't imagine a situation like that where locking out gears would be useful? I'm glad you aren't on the transmission design team. Or any other design team at all, with any input to the design of these trucks.

 

While I agree with most of what you stated, The "real fix" to not "needing" to lock out any gears, it's for the people who designed & programmed the transmission to... Do a better job... at picking shift points, versus load, versus speed...

NOW Having said that, I understand why the trany shifts like it does... They programmed it to the lowest common denominator, of where they don't get thousands, tens of thousands of people complaining that the trany shifts way too often, their 6 speed only shifted once, on this particular hill,... This 10 speed trany shifted 4 times, up practically every hill...

BUT, wait a minute, IMO why NOT use ALL the gears to keep the engine in its happy zone, for the most power, for the best economy, for not lugging and not revving as high as it does sometimes...

Anyways, I does bother me that the trany isn't using ALL, the gears it has, having driven a transport truck with, 5/4, 5/3, 5/2, 11, 12, 13, 14, speeds... There IS, a difference when you shift at the right time... or... shift 1 second too late and now you have to shift 2, 3, 4, gears to make it up the hill you could have made it up with just 1, or 2 shifts... ...

 

IMO, the bottom line for the OP, experiment with the various options. Do what feels comfortable for you. There are no real wrong answers. The truck won't let you select an option that will hurt it.

 

TRUE, But, the truck should be able to perform perfectly... On it's own.. JMO. That is why most automatic transmissions have a "D" set it and forget it...

EDIT; and... I am willing to bet, most people will be in the "wrong gear" most of the time/some of the time, using the manual setting, More that a few times the trany shifted out of the gear I had it in, on it's own... because, I F'd up... JMO or... Even worse, didn't shift up, and I had to shift or it wouldn't go any faster

 

I use tow/haul and set cruise control around 67 to tow a 7-8k travel trailer with our 2022 6.7. It would actually upshift into 10th on uphill inclines on the interstate on the way to Tennessee. Never downshifted unless I was using gas pedal instead of cruise. I saw no reason to lock out 10th if it wasn’t ever shifting out of 10th on its own.

 

Just because YOU have had issues picking the correct gear for a situation doesn't mean that is the norm. Just because the lowest common denominator, selecting D, is your preference because you have trouble getting the right gear yourself, doesn't mean this is a common problem for people. Maybe you live in the flat lands and that works for you. I can tell you for sure that in the mountains towing things regularly using the manual mode is a huge help. I know that without a doubt I am smarter than the transmission when it comes to choosing the right gear. Damn shame they do not offer a manual trans anymore because I would pay a TON extra tp pick my own gears and operate a clutch.

Ludicrous assumption that "it should" be able to do its job without any intervention regardless of the situation. Engineers can not possibly account for every situation. That is EXACTLY why they give the driver the option to choose gears themselves. They understand that the world is far to complex for something as simple as selecting D and forgetting about it. That will work but the experience is bound to be less impressive than a driver accounting for conditions the truck can not see and making adjustments.