The EB's torque curve starts even lower than the 6.2's if I'm not mistaken. The 6.2 peaks at a considerably higher rpm. You can't get a 6.2 with anything less than 3.55 and you can't get a 5.0 with anything less than 3.31. The 3.15's are EB-only.

 

Personally I would not want anything higher than a 3.55 for towing, no matter what engine I have. With air resistance the trannie will be constantly shifting to keep up speed, even on level highways. The trannie will be the first thing to go, not the engine.

 

That's what tow/haul mode is for. You may be surprised how well the EB holds the higher gears.

 

Your buying a truck to tow a trailer? Get the lowest gear possible /thread

 

No, am buying a truck to replace my girlfriends Toyota Vensa SUV. We will be using the truck for most of our travels including the ones where we won't be towing which is why I wanted the 3.15 originally to get the best mpgs as possible when not towing but still be able to pull the travel trailer when we need it. Looking for the best of both worlds.

 

um yeah, the 3.15 is a terrible idea then



you want the 3.73 and if possible the 4.10's and drive it gently, not like a hot rod and you'll be fine mileagewise

 

I tow a 7000lbs(full) with a 3,55 07 5,4..and it's good...but a 3,73 would be better.

don't know the gearing ratio of the EB but 3,15 seems really short gear to me:|

 

The 4 speed 4R75E in your 07 has a 2.84 1st gear, the 6R80 in the EB has a 4.17 1st gear.

Effectively, an EB with 3.15's has the same 1st gear overall ratio as a 5.4 or whatever with a 4 speed and 4.56's.

The OP wants to buy a specific truck for a couple reasons - he can get a great deal on it and he wants good unloaded gas mileage. He wants to know if he can tow a specific trailer with it, and that answer is YES. It's within limits. HOWEVER, for a DEDICATED Ecoboost towing vehicle, the best combination is one with max tow/HD payload and 3.73's.

 

GLC, I think some more questions need to be asked to say whether a 3.15 is the best for him. While first gear may be fine, once at speed, it is the same OD as the 4 speed and will have just as much trouble holding the gear as the 4 speed does. Also, if most of his regular driving is city, the lower gears would be better for gas mileage as it gets to the higher gears bquicker. Only if most of his driving is highway will the 3.15 gears be better.

 

how about at part throttle... very few people tow at WOT which is what the dyno sheets show

 

the only way a 3.15 would be acceptable would be if the OP drove the truck empty, in west Texas without wind...

 

Thanks so much for everyone who has chimed in. While the 3.15 would cut it, I will be getting the 3.55 or 3.73, although leaning towards the 3.55... 3.55 with electronic lock is only $45 more. I do however have a question with the hd package with a 3.73 do I lose the rear backup camera that comes in the xlt luxury package?

 

AFAIK, you can only get the HD Payload package (8200 GVWR) on select cab and trim packages.. I know they have it for the Super Crew with the 6.5' bed, but don't recall how high of a trim package it goes... I think you can get an Extended Cab, but it has to have the 8' bed on it. Same with Regular cab with the 8' bed on it...

I messed around with it on Fords "build it" web page, but don't recall specifics other than it took awhile to get the correct combo before the "HD" package was offered..

Good luck!

Mitch

 

I don't think you really need the HD payload package, but I'd definitely recommend the max tow with factory brake controller. Max tow requires 3.73's and is available with both bed lengths. That's going to give you between 1900 and 2000 lbs payload.

 

I'm towing a 7500lb trailer with the Max Tow Pkg and 3.73 gears and would never think about doing it with 3.15's!! As much torque as the Ecoboost has i can only imagine how that trans would be hunting for gears on steep hills with 3.15's while towing 7500lbs.. If your buying new and planning on towing then do yourself a favor and get the max tow pkg with the 3.73's. The difference in MPG between 3.55's and 3.73's is next to nothing but when it comes to towing is where you would notice the biggest difference!! Also the max tow pkg gives you a few other extras like the wonderful telescoping tow mirrors, integrated brake controller, extra payload, and a higher class hitch.
P.S. - The Ecoboost's towing capability when properly setup is utterly AMAZING!!