smokeywren

The rig:

2012 F-150 Lariat SuperCrew 4x2 with 6.5’ bed, 3.15 e-locker axle, EcoBoost engine, Reese “Pro Series” 5er hitch (the least expensive one Reese makes), Ford towing pkg that includes bigger radiator and tranny cooler. Lightly loaded with just the hitch, full of gas, DW and me. No pets this trip, and of course the camper shell that's usually on the pickup stayed in the barn for this trip. 2000 Keystone Sprinter 25RK (25’ with rear kitchen) fifth-wheel RV with one big slide, GVWR 7,900 pounds, wet and loaded hitch weight about 1,400 pounds (17 to 18 percent).

The good news – that EcoBoost drivetrain in tow/haul mode is a marvelous contraption. It towed my 8,000-pound 5er as good as my previous 7.3L diesel F-250. No problem with power and torque to maintain 68 MPH through the Hill country on I-10 west of San Antonio. It took most hills in fourth gear, but it got down to 3rd a couple of times. Climbing a grade in third gear at 68 MPH was still less than 4,000 RPM, thanks to the long legs of the 3.15 axle.The truck was working hard, but didn’t feel strained. MPG was not nearly as good as the diesel, but I didn’t expect it to be. We averaged 8.7 MPG cruising at 68 MPH for the 350 miles from Austin to Midland County via I-35 to San Antonio, I-10 to Ozona, and Texas 137 to home. That’s about 40 miles farther than my usual route through Llano and San Angelo, but a lot less 2-lane highway with others trying to pass.

The rig looked good. Very little sag in the rear end of the F-150, and the front axle stayed glued to the pavement, so driving and steering was “normal”. We got home before dark (on purpose) so no idea if my headlights would have been pointing at the stars. After sitting for three years being used as a residence in Austin, the tires still had 50 PSI, so I was able to tow it to a source for air. Pumped the tires back up to 65 PSI, and all was good. No problems whatsoever with the F-150 or trailer on that 350-mile trip.

Being overloaded over the GCWR, I was concerned about the rear axle temp, especially in the Hill Country. But my digital infrared temp gauge showed only 190° after a hot run in the hills, so the rear axle was not getting too hot.

The bad news – over 800 pounds overloaded over the GVWR and rear GAWR of the F-150, and almost 800 pounds overloaded over the GCWR of the F-150. We made it with no problems, but we were lucky.

The numbers from a CAT scale:

Steer axle = 3300 (front GAWR 3,750, no problem)

Drive axle = 4,680 (rear GAWR 3,850 = 830 pounds overloaded, including 138 pounds over rear tire capacty)
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GVW = 7980 (GVWR 7,100 = 880 pounds overloaded)

Trailer axles 6800 (combined GAWR 7,000, so the trailer was not overloaded)
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GCW = 14,780 (GCWR 14,000 = 780 pounds overloaded)
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Trailer tire capacity over 10,000 pounds @65 PSI, so no trailer tire problems, even though the tires are over 5 years old. Thank you Cooper ST225/75R15D tires on 6" wide rims (but Cooper no longer makes 15" trailer tires, so now I use Maxxis on my other trailers)

Bottom line. Anyone that claims they can tow an 8,000 pound 5er without being overloaded with an F-150 SuperCrew that does not have the HD payload pkg is probably blowing smoke. Show us the CAT scale weight on your rear axle.

SkiSmuggs

Thanks for the excellent post. The Max Tow package would have given you another 500 lbs of payload and put the rear GAWR at 4050. With my set up, I am 500 lbs over that with a 9500 lb fiver. And I am 390 over the GVWR, but 1560 under the GCWR. After 11,000 miles of towing, I have never felt overloaded. On the other hand, I would never have considered towing a fiver with your set up as I think Max Tow is an absolute minimum for doing that. I doubt that 3.15 axle would serve well in the mountains either. The next truck will have the HD Payload which was not available for 2011.

frieed

Any chance you meant 3.55 e-locker?

Nevermind, I see that is an option

smokeywren

In the 2012 4x2 EcoBoost SuperCrew, 3.15 open axle was std, and optional included 3.15 e-locker, 3.55 e-locker, 3.73 e-locker, and 3.73 limited slip. I ordered the 3.15 e-locker, hoping for better unloaded MPG. The 3.73 e-locker includes the max tow pkg, and the 3.73 limited slip includes both the HD payload pkg and the Max Tow Pkg. I wanted the max tow pkg, but not the 3.73 ratio that went with it.

atvtinker

The difference in mpg between the 3.15 and the 3.73 is about 1 mpg. You should have gotten the 3.73 gears and your truck wouldn't have had to work so hard. I get 22 mpg unloaded driving 60 mph on level ground. I average about 20 mpg all around daily driving, but I don't do a lot of "in town" driving.

ecobeest

Very concise post. Definitely shows the importance of building the truck for the use. Having the HD Payload + Max Tow gives me 4800 RAWR and 2177 payload. This enables me to pull my loaded 5'r and be within ratings.

FWIW my truck gets right around 21 MPG highway. In town much less than that but I try not to drive much in town if I can help it.

johndeerefarmer

Thanks for the post. I would definitely have wanted 3.73's and max tow.
You also might consider a tow tune from Southern Speed. It will make your ecoboost feel like you are driving a 6.0 Powerstroke..........
Night and day between stock and tuned......

smokeywren

I tried to make it clear that my EcoBoost engine with 3.15 axle ratio doesn't need more power to tow 8,000 pounds. Ford rates it at 8,400 pounds max trailer weight, and that seems about right as far as pulling power is concerned.

The problem is hauling capacity, not pulling capacity. My pickup would easily handle an 8,000-pound wagon-style trailer with minimal hitch weight without being overloaded over any of Ford's weight ratings. Think of a farmer's grain trailer or cotton trailer, which has almost no hitch weight. Like this one:


But with the 1,400 pounds hitch weight of the wet and loaded 5er, or even the 650 pounds hitch weight of my wet and loaded TT, plus the 200 pounds weight of the Leer shell, the GVWR of the tow vehicle is exceeded.

I'm not against towing tunes. In fact, I ran a DP-Tuner 60-tow tune for over 10 years in my F-250 diesel, and I wouldn't want to tow without it in that truck. But my EcoBoost doesn't need more power or torque to get the job done.