This is pretty basic and I'm hoping it's nothing, but here's what I've got...

This weekend I towed a single axle 6x8 utility trailer (not an enclosed) to my cabin and back - about 500 miles total round trip. Cargo on the way there was a low profile 100 lbs total and empty on the way home. Both there and back, it felt like I was towing much more than I was and it sucked the life out of my MPG and there was a lot of drag. I was averaging about 11 mpg per the display, which seemed about on par with what my fuel gauge and fill ups were. When I got to my cabin, I noticed a very hot metal smell from the front end area.

On my way home, the truck still felt like it was towing with a lot of drag. Truck seemed like it needed a lot of pedal to maintain cruising speed or to catch back up. Almost felt like the brakes were applied ever so slightly. I stopped to get gas and noticed the same hot metal smell. Suspecting a caliper issue, I put my hand near the calipers / rotors and none were abnormal heat wise. I got home and checked the rotors with my temp gun and all of the rotors were similar in temp. I checked my trailer and the hubs were normally warm and spun freely, so the trailer is not an issue.

I dumped the trailer and went back out onto the highway to do further testing and noted the sluggish, dragging feeling was gone and virtually non-existent. I'm still new to these trucks, but is there some feature or tow setting that it would automatically go into when it detects a trailer? Not sure if this matters, but I plugged my 4-flat trailer connector into the 7 way adapter.

 

What rear axle is on your truck?

 

 

3.55 elec. lock

 

hmmm, interesting. It was definitely windy today. I do not have the trailer brake controller. Would it activate even when towing a trailer w/o brakes? Would plugging into the 4-way outlet eliminate that (in addition to disabling it manually).

 

If the truck detects sway it will activate your truck brakes, since you do not have any on the trailer itself! I would hook that trailer back up and Disable the sway control to see how it feels! With that small trailer, you should not even know its even there

 

Interesting ... there are no stupid questions ...

I had the same situation towing one axle utility trailer empty one way and total of approx 500 lbs trailer and load on my way back. I had noticed the track's sluggishness and poor fuel economy. It was windy so I assumed the trailer drag was the culprit but it had a surprisingly significant impact on truck's performance. The sway control was on by default ... next time I will switch it off to compare.

... thanks for the question and the replies with tips ...

 

I'd invest a bit more time into locating the source of the smell. Sounds like a future breakdown so better to find it now.

 

 

Does your trailer have the folding ramp at the back that stands straight up when folded up? The ramp may be made of expanded metal with the holes in it like the one I had. I had a 2011 FX4 3.5 eco and pulled it empty with the ramp straight up and felt the same thing you did and got 11mpg. I then towed it folded flat on the bed of the trailer and got 15 mpg. I couldn't believe how much wind resistance that ramp created. My brother in law borrowed it and pulled it with his F250 5.4 with the same results.