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Discussion Starter · #1 ·
Hey guys,

Mostly a lurker on the forums and figured I'd ask for some towing advice from pro's. I'm not really a stranger to towing and have done so for many miles. However, reading up on some places were towing in 10th gear is a big no-no which I wasn't aware of.

In my old 03 Silverado gasser that I used to have, I always kept O/D locked out unless it was smooth with no hills. Since living in FL, it's mostly flat here. So towed with O/D on to maximize fuel economy. I pretty much do the same with my current 3.0, as I've always left it in 10th gear and doesn't struggle at all. But as I said, this seems to be a bad thing from what I've read

I'll basically be doing a trip from Miami to Orlando towing my race car. Highway is mostly flat with very few inclines if you even want to call them that here. What is best practice when towing? Keep it in 9th? 8th? I generally keep it around 65-70MPH.

Info on truck/rig:
2WD
3.0 Diesel
3.55 Rear end
Towing Weight with Car+Trailer = 5000lbs

I'll be doing an even bigger trip in about 3 weeks going from South-FL to Northern VA. So want to make sure I prolong the life of the truck by doing things properly. :)
 

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I think you are missing some information. Year of truck (I am not sure it was the same for 18, 19, 20, 21), trim, as higher trim levels mean lower total capacity in some cases, wheelbase as longer wheelbase means less capacity, and finally receiver towing or 5th wheel/gooseneck.

Having said that I am guessing you are fine. In order to be sure look up the towing guide for your year. Here is the link to the 2018 F150 Towing Guide. 2018 F150 Towing Guide

I pulled a camper with similar weight to yours and sometimes used the tow mode, other times I didn't. This was also in Florida. I think you need Forscan to enable the temperature display for both the engine and transmission. This really is helpful.
 

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Discussion Starter · #3 ·
The specs are
Super Crew Cab, Lariat, 5.5 Bed.

Tow haul mode is always used when towing. My main concern is transmission longevity and keeping EGT's down. Hence why I'm asking if 10th gear is a big no when towing.
 

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I may be missing something, but if Ford did not want you to tow in 10th gear, it would specify that in the owner's manual. The manual simply states that you should use tow/haul mode if your vehicle is so equipped. Common sense says that if your transmission is continuously hunting gears, it would make sense to lock out the higher gear(s).

There may be ancedotal evidence of transmission failures out there from people towing in 10th, but I suspect it may be an old wives tail, with some element of truth rooted from transmissions in the 90's (4L60E)
 

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I may be missing something, but if Ford did not want you to tow in 10th gear, it would specify that in the owner's manual. The manual simply states that you should use tow/haul mode if your vehicle is so equipped. Common sense says that if your transmission is continuously hunting gears, it would make sense to lock out the higher gear(s).

There may be ancedotal evidence of transmission failures out there from people towing in 10th, but I suspect it may be an old wives tail, with some element of truth rooted from transmissions in the 90's (4L60E)
The issue with towing in 9th/10th gear isn't a problem with the transmission; it is due to the higher engine load at lower engine RPM. This leads to increased EGTs with lower exhaust flow rates, which has been shown through multiple people's experience to cook the O-rings in the intercooler piping where it connects to the turbo.

Gear hunting can also be a minor issue with the 10R80 when towing, and locking out the top two overdrive gears helps with this. Older transmissions would hold gears longer due to the bigger differences between the fewer gear ratios. With the increased number of gear choices, smaller differences between ratios and modern electronics, the truck will downshift more result to stay in it's ideal power band, especially when towing.
 

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The issue with towing in 9th/10th gear isn't a problem with the transmission; it is due to the higher engine load at lower engine RPM. This leads to increased EGTs with lower exhaust flow rates, which has been shown through multiple people's experience to cook the O-rings in the intercooler piping where it connects to the turbo.

Gear hunting can also be a minor issue with the 10R80 when towing, and locking out the top two overdrive gears helps with this. Older transmissions would hold gears longer due to the bigger differences between the fewer gear ratios. With the increased number of gear choices, smaller differences between ratios and modern electronics, the truck will downshift more result to stay in it's ideal power band, especially when towing.
Good info. Is this specific to the 3.0L? I've run the engines on my 1-ton trucks up against their EGT limits for up to 5 - 10 minutes at a time, downshifting only if they cannot stay within limits, for all their lives, but I might just be lucky.
 

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I did some research on max tow capacity in Post #7 in this What is your payload capacity thread if you are interested.

Executive Summary: Based on your estimated total weight (car+trailer) of 5000 lbs, you shouldn't have any issues with capacity and would hope the same for towing in 10th gear on flat terrain. Now if you were towing a 10,000+ lb camper, my opinion might be different...
 
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Just stick it in tow/haul mode and keep on truckin'. You don't need to worry about EGT's , EGR's, DPF's, DEF's, or BMF's. The computers that monitor those parameters continuously adjust the engine and transmission operation to optimize operation and prevent problems. It's smarter than you are.

Now, if you have changed the software to delete some of those things, then you may have reason to think about them. If it's stock, don't. Remember, you're under powertrain warranty for 100,000 miles. I've towed cars and tractors with my 2021, and as far as I can tell, the truck doesn't care whether they are there.
 

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I have to admit I’m a little freaked out about EGT’s. Never had a diesel til this 3.0 and it’s completely off my radar. Probably need someone to talk me “down”. I’m not a habitual tow‘er but I’ve done some in some 100+ heat.
 

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Discussion Starter · #10 ·
Figured I'd post an update of my trip.

So I did purchase a Scan Gauge II and had it record all EGT sensors ( I think there is 4 ). Things to note
  • EGTs on average were about 580-600F. When Regen would kick on it would spike to about 700~850F
  • Towed in 8th gear the whole way. MPGs were roughly 18MPG based on the trip computer. So I suspect real world probably around 17ish as I think onboard dash over-estimates
  • Regen didn't really happen as often and long as I thought it would. Barely used any DEF. I had Scan Gauge II to display when an active regen was happening
Questions I have:
Since everything was flat, I really wonder if my EGT's would have spike above what my current range was if I had left it in 10th Gear. Everything in Florida is relatively flat. I could see in other states with high/steep grades. Guess one way to have found out would have been to pay attention to the EGTs while driving in 10th. But didn't as I wanted no risks lol.

Other than that, pulled like a champ. I've towed many times, but again never really thought of it until I saw a FB post saying always to tow out of 9/10th.

Some bonus pics:

Wheel Car Tire Land vehicle Vehicle


Tire Car Wheel Automotive parking light Land vehicle


Wheel Tire Car Cloud Sky


Wheel Automotive parking light Tire Car Land vehicle
 

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Thanks for the report and the photos. Those egt numbers are surprisingly low, at least to me. In my Caterpillar I raise the rpms when I see anything near 1,100 degrees F. I never knew just what these engines ran but those numbers sound comfortable. They would be higher on a long mountain run out west.
 
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Discussion Starter · #12 ·
Updated the title to this thread, as next week I will be making a much longer haul. From Miami, FL to Washington DC. Figured I'd post my results along the way.

Some info on what I am towing/towing with:
  • 2006 Mitsubishi Lancer - 3,100lbs
  • 2018 Econo Trailer open dec - 1,450lbs
Truck has around 62k miles. Will be doing an oil change with 5W40 Amsoil heavy duty along with fuel filter swaps this weekend.

This time around, I think I'll be hauling through Florida in either 9th or possible 10th gear with heavy monitoring of my EGT's for maximum fuel economy. If EGTs gets above 700+, I'll switch back to 8th gear pulling. Are there any reasons any of you would suggest against this? Besides possible high EGTs? Please definitely feel free to comment and provide feedback. Once I am out of Florida though, 8th gear will be the obvious choice for constant hill climbs and what not.

Tips for any hauls for me are always:
  • Ensure trailer tires are always inflated to the correct PSI
  • Always check your tie down straps when stopping for fuel/breaks.
Looking forward to seeing how it'll do on this trip!
 
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