chaselee

This weekend was really the first time I towed on the highway with this truck. Heres the rundown: 2013 fx4, 5.0, 3.55 gears, 35" tires on factory wheels, 5* tuned, airaid CAI, Magnaflow catback. This past weekend I towed a 16" lowboy with my side x side and my dads fourwheeler on it about 300 miles round trip. It had power, but at highway speed it was constantly back and forth between 5th and 6th gear. Sometimes it would hold 5th for a long time, even on flat ground. I was running the 87 octane tow/eco tune.

NastyFFX4

iTrader: (1)

I'd say maybe just the whole combination of the 35" tires, 3.55s, and trailer weight. I tow with my 5.0 but I'm still on stock tread and 3.73s. Zero issues here.

Fx4_5.0Man

iTrader: (1)

I tow with mine a bunch and if I have a decent trailer I just lock out 6th. Gas Mileage doesn't suffer much at all. They were born to rev, so let it rev! Lugging isn't its forte. I am happy with mine I have towed up to 6500lbs.

white08gt

just lock out 6th gear, use the tow-haul mode. running 35s is hard enough without at least 3.73s.

11screw50

no problems towing here, holds 6th just fine...but I have stock size tires (albeit a bit heavier) and 3.73's. I am towing a 6500# TT.

If it were constant shifting back and forth, i'd just lock out 6th and let it rev, easier on the trans.

terraformer

Yup, if you didn't use T/H mode that'd be the first culprit. Plus, the 3.73 (as stated above) really'd help with that larger rubber.

aiobst

Towed a 34' 8500# TT 5,000 miles last summer with 3.73s. Used T/H all the time, sometimes I locked out 6th, but then I stopped, it ran fine in 6th on the flat ground. It would downshift accordingly for hills, sometimes dropping into second for the 6%+ grades. I have everything stock, just added RAS.

Alamedasam

This was the very first time I towed with my F-150. Nothing at all like my F-350!
About 8,400 lbs.

GeorgiaMike

I've towed apx 7000 pounds with my '13 4x4 5.0 screw 6.5' bed and it hunts around a little for the right gear but then again inland South Carolina is very hilly in places. Biggest problem i had was stopping going down hill with horses in the back... bit of a pain.

zacharyz

Always lock out 6th when towing and keep it in tow mode. I towed a 8000 lb trailer across the country with a 5.0 FX4 with no problems or gear searching.