I'm intending to use a 2015 F150 EB 3.5 145"WB Max Tow Package for towing a 6000 lb dry TT with a GVW of 7700 and a total length of 28' (although box is only 24).

Now with the 10,700 towing and 2100 payload you would think I would be ok, BUT

I will be towing in the mountains of Colorado and other parts of the west and I am concerned about the downhill.

It is an interesting note on the HD Payload package (which i did not want because of the 8' bed requirement) that it is ONLY available with the 5.0L. I was a little puzzled by this since the EB has more torque at a lower rpm.

However I'm thinking it might have to do with the 5.0 having more displacement to use as engine braking on downhill. Yes the 3.5 has the oomph, but does the smaller displacement lack the drag for when you are coming down the mountain?

BTW I didn't want the 8' bed because the turning radius on these trucks is already atrocious, especially compared to the Ram. Like 8' difference.

Lastly should I be considering an F250 or the equivalent? Really would prefer not to have a beast for daily driving.

 

2,100 payload will NOT be on your door sticker.

 

Be aware that without the HD Payload pkg, the limiting factor affecting your useful payload carried in the truck will likely be your rear gross axle weight rating (GAWR).

For example, your 3.5L 145" WB selection will have about a 3800 lbs rear GAWR. The bare bone stock base model w/o any options will have a rear axle curb weight of about 1950 lbs. Assuming you have 12.5% (conservative) of your trailers GVW on the tongue (960 lbs) and an appropriate weight distribution hitch (100-200 lbs), you are quickly approaching a usable payload of less than 750 lbs.

Any options you add (other than the HD Payload Pkg), including trim levels other than the XL, will only decrease your useful payload. Sure, weight distribution will help put some of that weight on the front axle and the trailer axle, but not enough to give you much margin.

This data and more can be found in these specifications:
https://www.fleet.ford.com/truckbbas...tes_010815.pdf

 

Get the EcoB. Especially as you will be towing in Colorado. You want the turbo at high elevations.

As for payload, my 2011 MaxTow is a similar truck to the OP and has 2023# payload on the sticker. But it's a 4x2. A 2015 4x4 should be about the same with the Al body.

The HD Payload package is available with the 3.5L EcoB as well as the 5L. I would recommend it, but the only short WB version (142" in 2015) is a Reg Cab+8' bed. That sucks.

I tow a bit more weight than the OP and have a heavy tongue weight.
So stiffened the suspension and upgraded the tires to LT. The ride is now good enough for the load. I'm currently at 98% of payload and 102% of rear GAWR.

You have to be careful going down extremely steep, and winding Appalachian trails with a 35mph speed limit (20mph on the hairpin curves). Here I can either put it in 2nd gear and work the brakes hard (remember the trailer drum brakes will expand with the heat and need to be manually adjusted as you go down the hill), or put it in 1st gear and let the engine roar at 4000-5000rpm. Other than that I've never had a problem with hills.

 

Having towed through CO several times including the Million $ hi-way to Durango, the big down side of the EB motor is that it DOES NOT provide any adequate engine braking. I used up lots of my brake coming south on the 550, and my TT is 6200# loaded....
Just saying

 

You're misreading something. For 2015, the HD Payload pkg is available with the EcoBoost engine. However, it is not available with 145" or 122" wheelbase, so you have to order the SuperCrew with 6.5' bed or the SuperCab or regular cab with 8' bed. Apparently you're stuck on the SuperCab, so the only way to get the HD Payload pkg is with the 8' bed.


But I'll bet you'll love the SuperCrew with 6.5' bed. That's what I have.

Put that puppy in tow/haul mode and hang on! I recently towed through the Hill country of Central Texas while severely overloaded with a 20,000 pound gooseneck equipment trailer. In tow/haul mode, the tranny automagically downshifted to 2nd gear and we cruised along at 65 MPH at about 5,500 RPM on the steep downhill grades. No problems.


I'm completely happy with my SuperCrew with 6.5' bed. A tighter turning radius would be nice, but not required.

I suspect you'll be happy with the F-150 SuperCrew EcoBoost with 6.5' bed and the HD Payload pkg. But DO NOT buy an F-150 to drag a 7,700-pounds TT unless the F-150 has the HD Payload pkg.

My daughter was in the same boat. She wanted to drag a 7,000-pound horse trailer with a new F-150, but none were available with the HD Payload pkg without a 7-week wait while they built it for her. She didn't want to wait, so she bought an F-250 SuperCab shorty off the lot, and she and her hubby and my 17-year old barrel racer granddaughter are really happy wth the F-250. Her hubby uses it as a commuter car, and he loves it. GrandDaughter uses it to drag her horses to the rodeos, and she loves it. So if you want a SuperCab shorty, lots are available without having to wait while they build you an F-150 with the HD Payload pkg.


You probably won't find an F-150 with the HD Payload Pkg in stock. Dealers don't stock them because of low demand. Most folks that need that much weight capacity just go head and buy an F-250.


I had a '99.5 F-250 CrewCab with 8' bed for about 12 years. Great towing machine. But yeah, it was over 22' long and the turning radius was awful. But like any old farm boy, I made do.