09 F150 downshifting

BTDT with a 2010 F150. JMO so take it how you want, but that 6sp tranny is the worst tranny for towing I've ever towed with. The reason it's downshifting alot is because you can't lock out either OD's or select what max gear you want. The tranny will hunt ans shift all day long. I had the same issues towing 7300lbs going over simple interstate overpasses. It would shift 3-4 times during the whole process. Really irritating.
the plus side to the tranny is they greatly improved the cooling from 08. I used a Scangage to monitor tranny temps and the tranny stayed in normal temps all the time.
Tow haul mode won't change often the tranny shifts. It will just make the shifts firmer. BTDT

Tires are same size as original, ride is stiffer but not going to send me to chiropractor. Been driving on them about a week, It's just downshifts at hwy speeds that I'm surprised by, without the trailer.

Mrbillsa wrote:
I'm getting ready to pickup our new travel trailer next week. I have a FX4 with supercab, tow package, 5.4 V8. I put new tires on Goodyear dealer put G load rating on, might be overkill. I put aftermarket power fold tow mirrors on, and most recently a fiberglass topper. There's not a lot of extra weight on it, since I had a hard cover on it before topper. I've noticed the truck downshifting quite a bit, even when I touch the gas going downhill. Not sure if this is normal and just resign myself to driving in tow mode or what. I know the mirrors are catching a lot more air than the stock ones. Thanks in advance for input.

That thing is going to ride like a buckboard. If the tires are larger than stock, that will cause more downshifts and less power. Wind resistance causes a large amount of power consumption, all you can do is drive slower. Yes, use tow mode whenever the trailer is attached, it will be better for the transmission, help in slowing (some models), and may help in cooling.