To Tow / Haul or not to Tow / Haul?

[Konrad]

Hello All, I'm towing a medium size travel trailer (23 ft, about 6000lbs loaded) with a 2019 Hemi eTorque 3.21. Two years full time on the road now, 35k miles towing. Zero problems, plenty of power, excellent ride.
One thing I'm still unsure of is if I should be using Tow / Haul mode. Based on long term observation, truck seems to be sensing the load pretty well without T/H, gear shifts are adjusted properly and spot-on, it won't excessively shift or go into overdrive (7 and 8th) too often. Without T/H engine oil temperature is lower 8-15F, transmission temp 5-10F lower, mpg 0.5-0.7 better.
Except for mountain driving where T/H provides much better engine braking, does it even make sense to use it during regular towing? What's your take?

Sent from my Pixel 2 XL using Tapatalk

 

[Shots]

For that trailer/load I would use it, but you're not going to hurt anything if you don't. I think the T-H is more intended to make your drive more comfortable. It makes minor adjustments in how the truck acts (such as shift points and gear selection), but at the end of the day it's the same truck with the same physical gears.
Just a matter of preference. If you're happy with the way it drives the way you've been doing it, keep doing it that way.

 

[IvoryHemi]

Towing 6k lbs, I’d use Tow/Haul

 

[5thGenRebel_AMK]

I use tow haul almost every time I drive. It just changes shift points and holds gears longer. Essentially sport mode lol

 

[31RamIt]

I don't use it for my little 4000 lb travel trailer. Seems to keep my RPMs down and I get a lot better gas mileage on my longer trips.

 

[Bt10]

Find out if tow raises line pressure in the trans. If it does, you should use it for long trans life.

 

[Konrad]

Find out if tow raises line pressure in the trans. If it does, you should use it for long trans life.

Good point. I read somewhere that it locks the torque converter on lower gears as well. Trying to figure out what exactly TH does. Any idea on how to find out?

Sent from my Pixel 2 XL using Tapatalk

 

[Bt10]

Good point. I read somewhere that it locks the torque converter on lower gears as well. Trying to figure out what exactly TH does. Any idea on how to find out?

Sent from my Pixel 2 XL using Tapatalk

Ask a trans shop/race shop.

 

[Trooper4]

Hello All, I'm towing a medium size travel trailer (23 ft, about 6000lbs loaded) with a 2019 Hemi eTorque 3.21. Two years full time on the road now, 35k miles towing. Zero problems, plenty of power, excellent ride.
One thing I'm still unsure of is if I should be using Tow / Haul mode. Based on long term observation, truck seems to be sensing the load pretty well without T/H, gear shifts are adjusted properly and spot-on, it won't excessively shift or go into overdrive (7 and 8th) too often. Without T/H engine oil temperature is lower 8-15F, transmission temp 5-10F lower, mpg 0.5-0.7 better.
Except for mountain driving where T/H provides much better engine braking, does it even make sense to use it during regular towing? What's your take?

Sent from my Pixel 2 XL using Tapatalk

I tow heavier, and don't use it unless I get into mountainous terrain, and like you said, just watch the temps.
This is several years ago, but temps were low and it ran in 8th regularly when keeping speeds reasonable. Truck really was comfortable at 55/60. This was around Sacramento, CA., but hand calc MPG was little over 12 for the several thousand miles with no problems at all. Truck now has 45000 and has suffered no issues towing.

 

[Trooper4]

Find out if tow raises line pressure in the trans. If it does, you should use it for long trans life.

In hydraulics higher pressure means higher temps. ???

 

[JF19Longhorn]

I've always used T/H mode when towing anything but my empty open-car trailer. Always thought it was 'better' for the truck.

 

[Konrad]

I've always used T/H mode when towing anything but my empty open-car trailer. Always thought it was 'better' for the truck.

Well, that's what I'm trying to figure out. By simple logic if a given amount of work can be done at lower temps, lower rpm and lower mpg that should be better for the truck (or any mechanical system), right?

Sent from my Pixel 2 XL using Tapatalk

 

[JF19Longhorn]

Well, that's what I'm trying to figure out. By simple logic if a given amount of work can be done at lower temps, lower rpm and lower mpg that should be better for the truck (or any mechanical system), right?

Sent from my Pixel 2 XL using Tapatalk

Sounds logical.

Does the truck engine brake without T/H on?

 

[Konrad]

Sounds logical.

Does the truck engine brake without T/H on?

It does, however in TH the engine braking is better. Useful in the mountains for sure.

Sent from my Pixel 2 XL using Tapatalk

 

[Bt10]

In hydraulics higher pressure means higher temps. ???

But MUCH lower temps for the slipping clutches = win.

Well, that's what I'm trying to figure out. By simple logic if a given amount of work can be done at lower temps, lower rpm and lower mpg that should be better for the truck (or any mechanical system), right?

Sent from my Pixel 2 XL using Tapatalk

Work can be measured by throttle position also, not just rpm. Say 2000 rpm, when is more work being done? At 10% throttle or 90% throttle?

 

[SnowBlaZR2]

This is several years ago, but temps were low

How low?

 

[Konrad]

How low?

With my truck I'd average temperature differences as follows, towing the same trailer in similar conditions:

TH on:

Engine Oil: 226-232F
Transmission: 190-198F

TH off:

Engine Oil: 218-226F
Trans: 183-189F


Sent from my iPad using Tapatalk