Tow Haul

I'm one of those folks who did indeed check the manual for my 2003 Tahoe LT. It recommended using the tow haul button at all times when towing a trailer. So I use it all the time when towing.

KeithAS wrote:
I use it when pulling through a town with a lot of stop and go. The Dodge 3500 can pull the 8,000 lb. TT up 1-2ish percent grades at 60 mph without shifting out of 6th gear and with the EB on, tow haul is too aggressive going down hill.

Just set the cruise to the speed you want to decent at.

I use it when pulling through a town with a lot of stop and go. The Dodge 3500 can pull the 8,000 lb. TT up 1-2ish percent grades at 60 mph without shifting out of 6th gear and with the EB on, tow haul is too aggressive going down hill.

Just went across the Smoky Mountains into SC, back thru the mountains of NC, using T/H and mileage was actually about 10 miles more to the tank.

Not all tow/haul modes are created equal.Some just change shift timing, while others are more complex.
The Tundra has a more complex tow/haul mode.
During tow/haul control, the ECM controls the engine output, transmission shift schedule and shift timing
to ensure drivability when a trailer is towed. The tow/haul control includes a throttle control, shift schedule
control, wide open throttle shift timing control and AI-SHIFT control.

The conditions required for tow/haul control to operate are as follows:
- Shift position: D position (Tow/haul control does not operate in the S position).
Throttle control changes the relationship between the accelerator pedal depression angle and the throttle
valve opening angle.

During tow/haul control, the throttle valve
opening is increased by throttle control. As a
result, acceleration performance is ensured.
Shift Schedule Control
The shift schedule control changes the upshift and downshift schedules during tow/haul control.

For the upshift schedule, the upshift timing is changed to higher vehicle speeds, enhancing the use of
lower gears. As a result, drivability is ensured.
For the downshift schedule, the downshift timing is change to a wider throttle valve opening angle,
enhancing the use of higher gears. As a result, the frequency of gear changes is reduced, allowing optimal
shift quality.
Wide Open Throttle Shift Timing Control
Due to wide open throttle shift timing control, upshift timing is delayed to make use of high engine power
when the accelerator pedal is fully opened.

Wide open throttle shift control operates in 1st, 2nd and 3rd during tow/haul control.
Powertrain Cooperative Control
Through cooperative control with ETCS-i (Electronic Throttle Control System-intelligent) and ESA
(Electronic Spark Advance), and electronic control of the engagement and release speed of the clutch and
brake hydraulic pressures, excellent response and shift shock reduction have been achieved.
Also, On my Ford, no tow/haul mode means no exhaust brake.

Colo Native wrote:
Just wondering when to use Tow Haul? I know down hill is the best but any thoughts on the flat or uphill or just all the time?

Depends on the truck and tranny.
I've towed commercially over 800k miles in a 11 year period with LDT size trucks so I understand how to make a auto tranny last longer pulling 18k-20k GN trailers of various types.
The wifes '06 1500 chevy 4L60E tow/haul is worthless IMO. When pulling I simply don't use it as it keeps the TC clutch unlocked way too much at intermediate speeds especially down hill in 2nd gear. I find I can make it operate much more efficiently with less TC clutch slippage overall and much better down hill braking.
The '06 4L60E has no tap down feature for downhill braking. In fact with the TC unlocked in tow haul mode it has no engine braking. Might as well throw it in neutral and ride the brakes.

The 68RE/Allison and Fords big auto tranny T/H mode operate much different than our smaller sized auto transmissions.

Now having said all that many folks have no idea how to make a auto tranny operate for max longevity while towing or just around town so probably should stick with T/H mode.

Towing the 5er, 45000 miles, the tow haul is on. When towing a little trailer or car, think under 4000 total pounds, my truck doesn't even notice it, tow haul is off.

If you like your transmission in working order you'll use it anytime you are towing or hauling anything heavy enough that you can "feel" it affect your trucks performance.

I use T/H all the time when towing. Don't see any reason not to.

caberto wrote:
I agree with the above two posts... If I'm towing, it stays on. I don't mean to sound rash, but this isn't rocket science trying to figure out when to use it.

Totally agree and why I'd love to be able to have ordered my Sub with
the 5 speed manual