Tow Haul mode for off road (1 Viewer)

[Bruce]

Tow Haul mode appears to increase low end torque, making it useful for maneuvering a trailer in tight spaces as well as for normal driving with a trailer. I also found it useful to temporarily increase power while driving without a trailer. Recently, I was camped on Proctor Road near Madera Canyon in Arizona. There was a short section of steep rough road that I often crossed before reaching pavement. I found my OT handled this section better when I briefly turned on Tow Haul, then turned it off to return to the default Normal mode. Something to consider in your travels. Comments?

 

[jclaffee]

I'd be shocked if Tow Haul mode has an impact on low end torque. It doesn't change engine performance. It mainly just alters shift points.

 

[Bluegill]

Man, you were way down south!

I’ll try the town haul button this weekend. I’m headed to Box Canyon for a few days. I was looking at the tow haul button this afternoon thinking “I’ve never pushed you” and I was wondering what it does. I assumed it turns off over drive (typically the top gear but maybe the top few gears now that we have 10 of them?). It wouldn’t surprise me if it also adjusted shift points to take advantage of torque curves, thereby making the truck feel more torquey.

With my Land Rovers I would usually off road in sport mode because it did just this….adjusted shift points and held gears longer, thereby improving quick-pedal-push torque and also providing more engine braking while running fast on curvy dirt roads.

 

[Bruce]

Yes, I was in SE AZ for a month to escape the Colorado winter. I towed my 4k pound trailer 2,400 miles in the process, and was pleased with tow-haul mode, including starting from a stop.

In my 2021 Tahoe the only time I noticed any difference in power, rpm’s, or shift points was using tow-haul mode on steep downhills pulling a trailer, when the rpm’s were much higher.

Thanks, keep the comments coming.

 

[Bruce]

Could tow-haul mode engage the turbochargers at low throttle for more power to overcome inertia and gain the momentum needed to move trailers from a stop? The GX is my first turbo vehicle, so not sure what to expect.

 

[Bluegill]

I tried tow/haul mode this past weekend while off road. I didn't notice any difference. I kept the mode controller in comfort while on the long slogs through rocky trails in high-range gears. I used rock crawl mode quite a big in low-range with center & rear differentials locked while climbing. I also used Sport+ mode in high-range, high-speed runs on the wide-open and graded flat dirt roads.

 

[BENDOU]

I can't really tell that Tow/Haul increases torque in normal driving. However, when towing my 5300 lb off-road camp trailer, I tried Tow/Haul looking to see how it might affect the shock dampening. I do think it helped. That was what I was looking for. But I noticed that from complete stops such at a stoplight, it felt there was definitely more torque in the initial acceleration. I'm pretty convinced of this as I can tell when I forget to use Tow/Haul when I note the more labored initial acceleration from a stop. I had read somewhere that Tow/Haul locks out 9th and 10th gear. However, I had also noticed that when cruising on level highway at 70 mph, that pulling the shifter to manual mode that it was in 8th gear anyway when not using Tow/Haul. But as I mentioned at the beginning here, I can't tell there is any increased torque fromm a complete stop when not pulling my trailer.

I have wondered how it gets the increased torque. Watching the turbo boost gauge, I can't see the boost come in any quicker so I'm thinking it could be advanced ignition timing off idle. Just my WAG.

 

[ISU3GX]

Sharing as fyi, in the GX 7th gear is 1:1 with 8/9/10 all overdrive gears. Tow/haul locks out all overdrive gears as towing in overdrive skyrockets transmission temperatures.

I have not towed anything yet with the GX. I anticipate Tow/Haul will raise the shift point RPMs.

 

[BENDOU]

Sharing as fyi, in the GX 7th gear is 1:1 with 8/9/10 all overdrive gears. Tow/haul locks out all overdrive gears as towing in overdrive skyrockets transmission temperatures.

I have not towed anything yet with the GX. I anticipate Tow/Haul will raise the shift point RPMs.

Yes, Tow/Haul does raise the shift points.

 

[cmfhsu]

I find tow / haul makes a couple key changes (in high range - never used it in low range):

• It forces the car to start in first gear from a stop, even if the transmission is cold, which could feel like an increase in torque
• It chooses lower gears, which is an increase in torque
• It prevents the transmission from unlocking the torque converter clutch under high throttle applications, especially when you've manually picked a gear, which could feel like increased responsiveness (but not increased torque - in fact it probably feels less torquey)
• It locks out the top two gears (I think), which probably does not relate to what you're describing, since it's only at highway speeds with no change in low range

 

[BackRdRnr]

For pickup trucks I have owned tow/haul makes the transmission more responsive to downshifts to keep the engine in the torque range and it helps the transmission locked in without slipping by using a higher RPM. If there are other results in the GX from using the T/H I do not know about them.