Tow mode vs normal

[Glassman]

I pull a 7600 lb camper, which is essentially a giant wind sail. 2021 XLT, 3.5EB, Max Tow. I always use Tow mode and lock out gears 8,9,10. This essentially keeps the revs up and cooling better as folks have stated here. The 8,9,10 gears are overdrive gears and have thinner discs, so locking them out helps save wear and tear on the transmission. This also keeps revs up and prevents turbos from kicking in unless really needed. I went from 7.5 Mpg to 10+ mpg when I went to locking out the top 3 gears.

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[EricR]

Have I read correctly that there are separate transmission tables for the various modes?

If so, using Tow mode would keep your Normal mode transmission tables clean.

 

[mxwrk]

I towed an open 6x12 tandem axle u-haul utility trailer the other day through LA, and up to Santa Barbara. The trailer was very light and I kept it in normal mode going through LA traffic so it would kick over to electric, but otherwise was happy to keep it in tow mode to lock out the upper gears and use engine braking going down hills. This was a very light trailer but I liked that it didn't hunt around gears constantly.

 

[Atlee]

I towed an open 6x12 tandem axle u-haul utility trailer the other day through LA, and up to Santa Barbara. The trailer was very light and I kept it in normal mode going through LA traffic so it would kick over to electric, but otherwise was happy to keep it in tow mode to lock out the upper gears and use engine braking going down hills. This was a very light trailer but I liked that it didn't hunt around gears constantly.

That's exactly what I do. In stop and go traffic either in a small town or in road construction, i'm in normal mode. Once traffic clears, I go to Tow/Haul mode and lock out 8-10 gears.

 

[Leavenworth]

I use TH when pulling my 28’ 7200# travel trailer and love it. Especially the engine braking. I also use TH mode occasionally when on the local mountain passes for down hill braking in the curves. Loving my truck!

 

[scottmeiners]

I was towing with mine the first time last weekend and I have not determined which is the best for me. When in tow mode, the truck pretty much stayed in 8th gear at about 2.2 rpms and no boost. When I would switch back to Normal, it would stay in 10th gear and maintain my 65 mph, but the boost was constantly at about 7-10 pound range and out 1.6 rpms. So the question I have is, which method is more fuel efficient? is 2.2 and no boost better than 1.6 and no boost?

 

[mxwrk]

I was towing with mine the first time last weekend and I have not determined which is the best for me. When in tow mode, the truck pretty much stayed in 8th gear at about 2.2 rpms and no boost. When I would switch back to Normal, it would stay in 10th gear and maintain my 65 mph, but the boost was constantly at about 7-10 pound range and out 1.6 rpms. So the question I have is, which method is more fuel efficient? is 2.2 and no boost better than 1.6 and no boost?

Generally if you’re on the boost, you’re burning way more fuel. I prefer to let the mechanical gear reduction of the transmission to do the work. Keep the temps down.

 

[Samson16]

I

I was towing with mine the first time last weekend and I have not determined which is the best for me. When in tow mode, the truck pretty much stayed in 8th gear at about 2.2 rpms and no boost. When I would switch back to Normal, it would stay in 10th gear and maintain my 65 mph, but the boost was constantly at about 7-10 pound range and out 1.6 rpms. So the question I have is, which method is more fuel efficient? is 2.2 and no boost better than 1.6 and no boost?

I think the load relief and increased fluid circulation combined with lower turbo heat generation makes it a no brainer even if it costs a little to do so. We’ve had anecdotal evidence both ways posted here about towing mileage.

 

[Calson]

The question to answer is what Ford considers a "heavy load". With GM it is defined as a load that exceeds 75% of the GCWR of the tow vehicle which is not ambiguous and so is useful.

I have used engine braking but it is by no stretch of the imagination as useful on a downgrade as an exhaust brake with a diesel engine, having done heavy towing with both. My diesel pickup had a tow rating of 17,500 lbs and my half ton F-150 has a tow rating of 14,000 lb but they are vastly different vehicles in most respects. The diesel had a heavy duty Allison transmission and I could use either Tow Haul or the exhaust brake or both. Uphill I used Tow Haul and kept an eye on the ATF temperature. Downhill I used the exhaust brake and the GM cruise control that managed downshifts exceedingly well.

I also view brake pads as cheap to replace as compared to having to rebuild a transmission.

From the manual:


TOW/HAUL - 4X2

For improved transmission operation when towing a trailer or a heavy load. This mode moves upshifts to higher engine speeds to reduce the frequency of transmission shifting. This mode also provides engine braking in all forward gears, which slows your vehicle and assists you in controlling your vehicle when descending a slope. The amount of downshift braking provided varies based on the amount you press the brake pedal. The system tunes the steering and suspension to enhance driving comfort when towing or carrying heavy loads. The electronic locking differential is available below 25 mph (40 km/h). See Switching the Electronic Locking Differential On and Off - 4x2.

TOW/HAUL - 4X4

For improved transmission operation when towing a trailer or a heavy load. This mode moves upshifts to higher engine speeds to reduce the frequency of transmission shifting. This mode also provides engine braking in all forward gears, which slows your vehicle and assists you in controlling your vehicle when descending a slope. The amount of downshift braking provided varies based on the amount you press the brake pedal. All four-wheel drive modes are selectable in tow/haul mode. This mode does not default to a certain four-wheel drive mode and maintains the previous selection. The system tunes the steering and suspension to enhance driving comfort when towing or carrying heavy loads. The electronic locking differential is available below 25 mph (40 km/h). See Switching the Electronic Locking Differential On and Off - 4x4.

So, I came here to ask and received way more information than the "manual" that took a few minutes to look up gave me.

 

[Samson16]

The diesel had a heavy duty Allison transmission and I could use either Tow Haul or the exhaust brake or both. Uphill I used Tow Haul and kept an eye on the ATF temperature. Downhill I used the exhaust brake and the GM cruise control that managed downshifts exceedingly well.

Well there you go then. See, with Fords you use the exhaust brake on the uphill. Try that next time and see if doesn’t turn your frown upside down.

 

[Samson16]

@Calson I apologize for the quip. Not my best behavior there.

 

[Samson16]

One aspect of tow/haul for PBs is the impact on the HVB. I drove home from work unloaded in tow/haul at 65mph when able and gears 8-10 locked out. 21mpg and the HVB SOC rose from 45% to 68%. I saw 70% briefly.

 

[Samson16]

That was a momentary screen grab during the drive. The boost air temperature is meaningless for this

 

[Samson16]

The strategy seems to maximize HVB availability for those true load situations so driving along empty in tow/haul really banked some SOC

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