Kowgirl2

I have a newly purchased 2016 F150 Lariat and would like to know how to turn off overdrive while towing. My 2007 King Ranch had a button. Tow/haul mode doesn't help.

GMC to Ford

You can shift to "Manual" and use the +- button to select M5. It locks out OD and all gears from M1 - M5 operate normally.

ON EDIT: After reading my response, it may be confusing. Two methods with tow haul selected:
Preferred: In DRIVE, use the +- button to select 5. It locks out OD (6) and all gears from 1 - 5 operate normally.
Alternate: In MANUAL, use the +- button to select M5. It locks out OD, but requires you to upshift and downshift (M1-M5) with the +- button. This option allows you to hold gears longer.

When I tow, I keep in in DRIVE with 5 selected, but shift to 6 on downhill runs.

moparado

You can try locking out 6th gear and see if that works.
The Owner's Manual explains how to.

Edit: GMC you beat me to it.

KingDeleted

whether you have console or column shift, there should be a +/- button. If you hit the minus button it will show all available gears on your dash screen. Just press minus again til you’re good to go.