^^I agree. 3.73's are my choice as well.

3.15's and planning to tow up to 10k miles a year is a disaster in the making.

 

Then why does Ford rate that combo for 8400#? We all know that people here tow over limits without breaking a sweat (and give us a hard time when we advise not to exceed limits) and that would actually be within limits.

I'm not trying to be pissy, I'm just saying that it can be done without problems. Of course, 6th gear would be useless but who says you have to use it?

Again, a max tow rig would be the BEST choice, of course.

 

I'm not arguing that it can't do it, but there are much better options. He doesn't own the truck yet, buy the best possible truck to fit it's required uses.

for some one who is going to be towing 10k miles a year, it's smarter to have a truck that will do the job well, not one that will do it ok.

Why buy a truck with a 6 speed to only use 5 of the gears? I'd rather buy the correct truck to fit my needs than to have to limit my truck to 5 of it's 6 gears.

 

The 6th gear would come into play when you are NOT towing.

 

It will come into play while towing. You cannot lock it out. Also 5th is a OD gear so it is a good possibility that it would have to go to 4th just to maintain speed. The higher the rear the more this will happen.

 

You are missing the point. He is buying it to tow. Why would you essentially delete a gear for the trucks primary use. If he towed 500 miles a year, who cares and maybe you could convince me but 10k miles a year is going to make me buy the correct truck for the job.

How many people do you see who go buy a truck with 3.15's to tow 7500 lbs? I bet the only people who do that are uninformed and found the truck on the lot and didn't think it'd make a difference.

There is a reason ford offers 3.73s and 4.10's with Max tow and not 3.15's. Because one does it better than the other. Only reason 3.15's are probably even offered are for max MPG for the ecoboost equipped trucks.

 

Yes you can lock out 6th gear if you wanted. Even 5th gear for that matter. When i tow in the mountains i always lockout 6th gear. I was tired of the trans constantly shifting back and forth. It is only 4-500rpms difference between the two gears but with the cruise set at 60-65mph in 5th gear at 2000-2200rpms i found that is my trucks sweet spot.

 

Then that is new as with tow/haul on mine, you cannot lock out any gear.

 

2011+ have the option to either go manually and force the gear you are in or lock out a gear starting with 6th and working your way down.

I'm still unsure of the manual route though, if any one else has noticed your tow/haul light goes off when going into this mode. I need to read the manual, but i've been hesitant so far to leave it in manual mode while towing.

 

Losing tow/haul doesn't help much if your towing. I expect that with a 3.15, even 4th would be tough to hold at times.

 

All i do is turn the tow/haul on, put the transmission in the "D" position and if i come upon a bunch of steep inclines i hit the minus button for the manual shift and it locks out 6th gear. You will then notice on the dash you only have gears 1-5.. The tow/haul light does stay on..

 

Not when you move the gear shift into M

 

I believe you since i have never tried. So does that mean you are not suppose to tow anything using the Manual shift??????

 

I have yet to tow 6500 pounds with my F150, but I have the 3.55 locker and I yanked a ~4000# Ditch Witch and trailer just fine without any hunting on my Ecoboost. If the OP's truck has the towing package he'll have the wiring harness in the dash for the Factory Trailer brake controller. I think you can find them on eBay less than what Ford Accessories wants and the install is very simple. However, you do have to take the truck to the dealer for them to activate it in the PCM. Whether your dealer charges to do that depends on how nice they are. You can also just pay them to install it.

Just to confirm what's already been said:

Tow/Haul does not work when the trans is in M mode. It's actually a bit redundant because the torque converter behaves as if its in tow/haul mode (only you're picking gears). If you're in D you have "Progressive Range Select" which lets you lock out gears starting from 6th and working your way down. You can lock out all but 1st if you wanted.