Heavy Tow Cross-Country Experience

I have a 2018 SR5 Crewmax, 5.7L, 4x4. It has a BAMufflers 10" exhaust, a 3/3 lift (Bilstein up front, Toytec shackles and a 1" block in the rear), Firestone air bags with daystar buckets, on-board air, E-rated BFG All terrains (275/70-18), TRD rear swaybar, and a host of other mods (winch, bumper, rock rails, skid plates, etc). She's a heavy beast. I've done a lot of towing (and formerly worked as a truck driver), so I'm pretty comfortable with her capabilities. In the past, she's pulled up to 8,000# horse trailers, and has pulled much, much heavier loads at low speeds on the farm.

For work, I am relocating to the Folsom, CA area. We are currently in Salt Lake City, about 80% of the way from Chicago to California. We've been talking about buying a travel trailer for years, and in this age of COVID, we decided to pull the trigger and buy one. We ended up selecting a 28' Jayco Jay Flight SLX bunkhouse. Empty, it weighs about 6800#. Add 2 propane tanks, 40 gallons of fresh water, and all of the other crap we loaded on board (food for 3 plus a dog for 1.5 weeks, clothes, stuff that didn't make the moving truck, the boxes of ammo that the movers refused to take, etc.), and the trailer is at its max weight. On top of that, I'm moving 3 bikes, an ARB freezer full of food, a 200# generator, and a 14 gallon fuel tote. And 2 adults, a child and a mini-schnauzer. Yes, I am undoubtedly over GCVWR and GVWR. No, I'm not bragging. And on future trips, I'll be much lighter...but for the intro trip, this has been quite an adventure. (We carry the water so that we have on-board water for the frequent family potty stops, and for several dry sites we've camped at on the way).

I'm running an Equalizer E4 sway control hitch, about 30# of air in the airbags, 70# of pressure in the truck tires, 65# in the D-rated trailer tires. We ran from Chicago up to Wisconsin, across Minnesota, through the Badlands, Custer State Park, Wyoming, down into Colorado, then back up to Wyoming and across to Utah. We've pulled 9,000# elevations, and run up and down a lot of mountain passes. Some have been on major highways (e.g. 90), and some have been on backroads passes.

Running the flat midwestern states the first day, I had the cruise set at 66 and let the truck work. Running in tow-haul, drive, she did a good job. Most of the time was spent in 5th gear, TC locked. She'd drop to 4th or even 3rd on a few hills, but on the flats, with no headwind, she did great--about 9mpg.

When we were in the badlands, we ran into a bad storm that we tried to avoid. While I didn't want to run that fast, we had to dash north to avoid a bad front coming through, and we had 1.5 hours at 75mph. For that run, she dropped to under 6mpg.

When we started getting into the mountains, drive and cruise were no longer options. In cruise, it would not hold the TC locked, and she would drop to 4th and then 3rd with the TC unlocked. Even with the stock trans cooler pinned open, the trans would hit 240-245 degrees and the engine would hit 205 degrees. After that, I had a change in direction.

For the past couple days, I've been using tow-haul, manual shift mode and my right foot to control my speed. Even with some massive headwinds, I've been able to hold 4th gear 95% of the time, with the TC locked. At times, we get into 5th (rarely). Engine holds flat at 195 degrees, and the trans holds around 180 degrees.

On larger hills, she drops to 3rd and unlocks the TC. She builds heat quickly in that mode. If I can hold 58mph or more, she will hold 4th, locked. Under 58, she drops to 3rd and heats up. My threshold is 230 degrees; when the trans hits that, I slow down. At around 50, she will pull 2nd gear at a higher RPM, and in that mode, the trans cools down quickly to around 210 degrees. That spot between 50-60mph is a no-go zone; you either go faster (if possible) or slower. I'm anxiously awaiting OVTunes TC lock feature, as that will enable pulling a lot of hills in 3rd locked.

Even on some pretty massive climbs, she has had no problems pulling. Sure, diesels pass me at 70mph on the climbs, but she will hold 60 up most hills, and even on the massive ones, she will hold 45 comfortably, at partial throttle. We had one hill on a 2 lane road in Colorado where I dropped to 1st gear and she walked up it.

The stock brake controller has been great, and I can't say enough about the Equalizer hitch. Even with massive winds and a 28' trailer, the sway control has been wonderful.

Downhill, the truck is fantastic. Every hill can be run in 3rd or 4th, the trans does not heat up, and the brakes don't have to be touched. I've been really impressed with how she descends.

I highly recommend the Firestone bags. I have them plumbed independently (not linked side to side). Between those and the rear sway bar, the truck is dead-stable for towing. With the weight distribution hitch, I have the front about 1/2" below stock height, and the truck and trailer are nicely leveled.

Towing mileage has varied between 7-10mpg dependent on wind. We're headed west, typically into pretty massive headwinds. Seeing 7.5mpg is not uncommon. The 38 gallon tank gives reasonable range.

All in all, I've been incredibly impressed with the truck and trailer combination. I wouldn't tow this heavy if it wasn't necessary, but every aspect of the truck's setup has been golden. I'd love to have the power and mileage of a diesel, but it would add tens of thousands of dollars to my truck cost. I'm spending a lot more on fuel, but future trips won't be this long or this heavy.

I'll share more about the trip in a future post. We had a site that we set up at and then got dumped on, and a lot of campers got stuck trying to pull out of the dirt roads that had turned to muck. The Tundra scratched in 4wd a bit, but pulled us out. She's been great. I just wanted to drop some notes here while the figures were fresh in my mind.

 

Great write up. Thank you!

 

Got any photos of this adventure?

 

Yes...but I'm not sure how best to share them here. I try to minimize my digital footprint in some ways, and I don't have any photo sharing sites that are public. I'll try to figure that out...

 

Stupid question: how do you know when the TC is locked

 

What an adventure!

Folsom is about 15min from us. Nice area.

 

With the fusion obd app you can get lock up feed back

 

I just monitor the RPMs. When the TC locks, RPMs drop and then match to speed. When the TC unlocks, the engine will rev not in full sync with increases in speed.

 

Thank you for the great write up and experience!

 

Thanks for sharing, you certainly seem to know what you're doing. Did you end up doing the other post/thread you mentioned?