Tow Haul Mode

[valhalla360]

I realize Tow Haul Mode isn't new but only recently got experience with it and figured I would share some thoughts.

We've had the truck (2008 F250 V10) for 3 years but life only allowed for some local trips in relatively flat areas and I never remembered turn it on. This year we can't get out of the country for the winter, so we loaded up and headed west.

On flat roads and accelerating, I'm kind of indifferent to it holding the gears a little longer. Doesn't really impact the driving experience much.

What surprised me is the downshifting when coming to a stop and semi-automatic downshifting on hills (tap the brake and it downshifts). At first, I just heard a whining coming to a stop light and until I caught on the truck was downshifting to help slow down, I thought something was wrong.

This truck really holds speed nicely on steep down grades. We've had several 6-7% downgrades of several miles this fall and almost never have to touch the brakes (RPM never going much over 3000 or making any really noticeable noise).

I drove my Dad's trailer out to Phoenix for them a couple times and coming down out of Flagstaff, you had to pay attention. It was a 3/4 ton dodge van with a 360 and even downshifting, you really had to work the brakes to keep speed from getting out of control and the engine was screaming if you let the speed get too high.

Then our first truck was a 1992 F250 with the 7.3 diesel (but before they added turbo). Generally loved the engine but it did almost nothing to help out on downgrades.

Then I found myself playing with it in some of the national parks not towing. Lots of steep switchback roads where you want to go 20-40mph. Following cars that are riding the brakes pretty much for miles and one tap and it downshifts and just strolls along without having to touch the brakes but when you hit a straight section, no need to touch the gear shift, just give it some gas and she shifts to a higher gear.

I haven't had a diesel with the newer exhaust brakes but this truck really does such a nice job downhill, I can't see having a need. Mind you we are pulling a 7500lb trailer so up hill is no issue even with some altitude thinning the air out.

Hope people find this useful.

[rjstractor]

wopachop wrote:
My 03 silverado would shift really rough on Tow Haul mode. Buddy with the same truck noticed the same thing. Shifted hard enough to make you think it was better to leave it off for that particular truck.

Currently have an 02 7.3 and all it has is a button to ditch 4th gear. Not sure if it adjusts shifting and torque converter slippage.

The transmissions of almost 20 years ago were different animals. The 2005 Chevy I used to have acted similarly. Yes, the button in your Ford just turns off the overdrive.

[Cummins12V98]

Grit dog wrote:

Cummins12V98 wrote:

shelbyfv wrote:
I think engaging tow/haul will also keep a good charge going to the trailer battery.

I will have to think about that one!

I think he means higher rpms (theoretically) in tow haul equates to higher alternator output. (like my old Chevy).
But as you also know, the charging systems are quite regulated on newer vehicles and long trips, the rpms won’t be any different on the open road tow haul or not.

Got it!

I have to say on 10 hour towing my residential frig is right where it was at the beginning of the trip.

[NRALIFR]

shelbyfv wrote:
Actually, what I have read is that with Tow/Haul engaged the alternator is programmed to keep providing a significant output rather than dropping down so much after it replaces the starting draw. This may not be true with all brands or years. I haven't verified if this is the case with my Ford, it's just something I read that I thought was interesting and a welcome feature. I have a little meter I can plug in to the 12V receptacle, maybe I'll investigate the next time I drive the truck.

I can’t recall ever reading or hearing of any effect of tow haul mode on the charging system on Ford trucks. There is however a stationary engine operation ECM mode that can be enabled called Battery Charge Protect. It’s only for supporting heavy electrical loads while the engine is running, parking brake is set, and shifter in neutral. When that mode is enabled, it will increase the idle as needed up to 1200 rpm to maintain the battery voltage while using tools or accessories that are drawing significant amounts of power from the truck.

:):)

[wopachop]

My 03 silverado would shift really rough on Tow Haul mode. Buddy with the same truck noticed the same thing. Shifted hard enough to make you think it was better to leave it off for that particular truck.

Currently have an 02 7.3 and all it has is a button to ditch 4th gear. Not sure if it adjusts shifting and torque converter slippage.

[shelbyfv]

Actually, what I have read is that with Tow/Haul engaged the alternator is programmed to keep providing a significant output rather than dropping down so much after it replaces the starting draw. This may not be true with all brands or years. I haven't verified if this is the case with my Ford, it's just something I read that I thought was interesting and a welcome feature. I have a little meter I can plug in to the 12V receptacle, maybe I'll investigate the next time I drive the truck.

[Grit_dog]

Cummins12V98 wrote:

shelbyfv wrote:
I think engaging tow/haul will also keep a good charge going to the trailer battery.

I will have to think about that one!

I think he means higher rpms (theoretically) in tow haul equates to higher alternator output. (like my old Chevy).
But as you also know, the charging systems are quite regulated on newer vehicles and long trips, the rpms won’t be any different on the open road tow haul or not.

[Cummins12V98]

shelbyfv wrote:
I think engaging tow/haul will also keep a good charge going to the trailer battery.

I will have to think about that one!

[Edd505]

IdaD wrote:
I run TH and EB most of the time, although I don't generally run EB this time of year because I don't want to be in the habit of putting it on when it's below freezing every night. EB and ice isn't a good combo.

EB exhaust brake?

[shelbyfv]

I think engaging tow/haul will also keep a good charge going to the trailer battery.

[Cummins12V98]

IdaD wrote:
I run TH and EB most of the time, although I don't generally run EB this time of year because I don't want to be in the habit of putting it on when it's below freezing every night. EB and ice isn't a good combo.

Where is your sense of adventure???

[Grit_dog]

phillyg wrote:
I activate tow/haul when accelerating and decelerating, but I find I can deactivate it at speed on level ground with no headwind. If the trans shifts out of OD I know it's time to activate it again.

FWIW, there’s no need or benefit to disengage it. Your truck will go into top gear in tow/haul and maintain it until it needs to downshift.
But doesn’t hurt to switch in and out either if that’s what you want to do.

[IdaD]

I run TH and EB most of the time, although I don't generally run EB this time of year because I don't want to be in the habit of putting it on when it's below freezing every night. EB and ice isn't a good combo.

[Cummins12V98]

Start truck, engage both. Good for the Turbo, good for the trans. Keeps engine in a good rpm for no lugging/downshift acceleration. Oh yea brakes last forever.

[DustyR]

BB_TX wrote:
I engage tow/haul as soon as I hook up the 5er no matter the distance, speed, or terrain. And I use tow/haul descending some steep winding grades even without the trailer behind. Less need to use the brakes.

x-2

Welcome to the world of 'transmission grade braking'. Couple that with an engine brake and drive with ease. Modern technology has helped the towing public greatly.