EcoBoost and 3.31 gears
12-08-2011, 10:28 AM
#11
Grumpy Old Man
Ford's GCWR specification is a very good indicator of the difference in towing power of the various engine/axle ratio combinations. For a SuperCrew EcoBoost:
4x2 3.15 ratio = 14,000 GCWR
4x4 3.31 ratio = 14,000
4x2 3.55 ratio = 15,300
4x4 3.55 ratio = 15,500
4x2 and 4x4 3.73 with max tow pkg and heavy duty payload pkg = 17,100
So no measurable difference in power and torque at the rear wheels between the 3.15 and 3.31 ratios.
About 10 to 11 percent increase in the weight you can safely tow if you move up to the optional 3.55 ratio, or 22 percent percent increase in the weight you can tow if you move up to the optional 3.73 ratio with the max tow pkg.
If you're not overloaded over the GCWR or GVWR of the tow vehicle, then the EcoBoost will tow the weights indicated by the GCWR without worry about overheating or straining something in the drivetrain or suspension.
Ford's tow ratings in the 2012 RV and Trailer Towing Guide ignores the GVWR and simply subtracts the curb weight of a pickup with no options from the GCWR. For example my tow rating is 8,400 pounds. With a GCWR of 14,000 pounds, that assumes my wet and loaded tow vehicle weighs no more than 5,600 pounds before I tie onto that 8,400 pound trailer. Well, big surprize but my Lariat SuperCrew 4x2 with spray in bedliner, Leer camper shell, Darling Wife and the puppydog, plus a few tools and jacks, is going to weigh a lot more than 5,600 pounds. So my real-world tow rating is a lot less than Ford's number would indicate.
Subtract about a thousand pounds from Ford's tow rating and you'll have a good idea of the max trailer weight you can tow without exceeding the GCWR of the EcoBoost. For example, if you have a 4x4 with 6.5' bed and the max tow pkg, the tow rating is 11,000 pounds. But that number assumes you have XL trim with no options, and absolutely nothing in the truck except a skinny driver. But nobody tows that way, so that 1,000 pound deduction is for fancier trim with power everything, sweetheart with you, and some tools in the toolbox in the bed. Now you're close to a real number.
For example, the tow rating of my EcoBoost is 8,400 pounds. But I know that if I get on a CAT scale with my cargo trailer weighing more than 7,000 pounds, I'm going to gross more than my 14,000 GCWR. That's because I didn't order an XL with no options, and Darling wife and the puppydog and some tools will be in the truck with us, along with a spray-in bedliner and a camper shell over the bed.
Folks that state "if you tow" should expand their "if". If your trailer will never weigh more than 5,000 pounds, then the stock 3.15/3.31 ratio will be all you need. For trailers between about 5,000 and 8,000 pounds, the 3.55 will be a better towing ratio. But if your trailer is over about 8,000 pounds, then you'll probably be glad you have the 3.73 ratio.
My trailer has a GVWR of 7,000 pounds and will usually weigh about 6,000 when loaded. I tow that trailer only a few times a year, and the pickup will not have a trailer tied on for 90 percent of the miles it gets driven, so I'm confident that with a 3.15 axle ratio = tow rating of 8,400 pounds it will be all the truck I need for that trailer, while giving me good MPG when not towing.
4x2 3.15 ratio = 14,000 GCWR
4x4 3.31 ratio = 14,000
4x2 3.55 ratio = 15,300
4x4 3.55 ratio = 15,500
4x2 and 4x4 3.73 with max tow pkg and heavy duty payload pkg = 17,100
So no measurable difference in power and torque at the rear wheels between the 3.15 and 3.31 ratios.
About 10 to 11 percent increase in the weight you can safely tow if you move up to the optional 3.55 ratio, or 22 percent percent increase in the weight you can tow if you move up to the optional 3.73 ratio with the max tow pkg.
If you're not overloaded over the GCWR or GVWR of the tow vehicle, then the EcoBoost will tow the weights indicated by the GCWR without worry about overheating or straining something in the drivetrain or suspension.
Ford's tow ratings in the 2012 RV and Trailer Towing Guide ignores the GVWR and simply subtracts the curb weight of a pickup with no options from the GCWR. For example my tow rating is 8,400 pounds. With a GCWR of 14,000 pounds, that assumes my wet and loaded tow vehicle weighs no more than 5,600 pounds before I tie onto that 8,400 pound trailer. Well, big surprize but my Lariat SuperCrew 4x2 with spray in bedliner, Leer camper shell, Darling Wife and the puppydog, plus a few tools and jacks, is going to weigh a lot more than 5,600 pounds. So my real-world tow rating is a lot less than Ford's number would indicate.
Subtract about a thousand pounds from Ford's tow rating and you'll have a good idea of the max trailer weight you can tow without exceeding the GCWR of the EcoBoost. For example, if you have a 4x4 with 6.5' bed and the max tow pkg, the tow rating is 11,000 pounds. But that number assumes you have XL trim with no options, and absolutely nothing in the truck except a skinny driver. But nobody tows that way, so that 1,000 pound deduction is for fancier trim with power everything, sweetheart with you, and some tools in the toolbox in the bed. Now you're close to a real number.
For example, the tow rating of my EcoBoost is 8,400 pounds. But I know that if I get on a CAT scale with my cargo trailer weighing more than 7,000 pounds, I'm going to gross more than my 14,000 GCWR. That's because I didn't order an XL with no options, and Darling wife and the puppydog and some tools will be in the truck with us, along with a spray-in bedliner and a camper shell over the bed.
Folks that state "if you tow" should expand their "if". If your trailer will never weigh more than 5,000 pounds, then the stock 3.15/3.31 ratio will be all you need. For trailers between about 5,000 and 8,000 pounds, the 3.55 will be a better towing ratio. But if your trailer is over about 8,000 pounds, then you'll probably be glad you have the 3.73 ratio.
My trailer has a GVWR of 7,000 pounds and will usually weigh about 6,000 when loaded. I tow that trailer only a few times a year, and the pickup will not have a trailer tied on for 90 percent of the miles it gets driven, so I'm confident that with a 3.15 axle ratio = tow rating of 8,400 pounds it will be all the truck I need for that trailer, while giving me good MPG when not towing.
Last edited by smokeywren; 12-08-2011 at 11:03 AM.
12-08-2011, 10:30 AM
#12
with the six speed transmission, the 3.15 geared rear end STILL has MUCH better overall gearing (pulling power) in 1st than the old four speed did with 3.73 gears. add to that an ecoboost motor making gobs more torque down low and i really don't see a reason to not spec the low number gears. you will have ample pulling power, and when unloaded will get better mileage. the only drawback i can see is that you might not be able to hold sixth gear while pulling a big load, which really doesn't matter since you can manually lock it out or control it manually all together with the new transmission.
my biggest regret is not getting a 2wd truck with the 3.15 gears. after owning my fx4 with 3.73 gears, i really see no reason for it. even with bigger tires, it has still shifted into third freaking gear before i get through an intersection! this is a half ton pickup, not a stump pulling 1 ton.
my two cents if i had it to do over again.
my biggest regret is not getting a 2wd truck with the 3.15 gears. after owning my fx4 with 3.73 gears, i really see no reason for it. even with bigger tires, it has still shifted into third freaking gear before i get through an intersection! this is a half ton pickup, not a stump pulling 1 ton.
my two cents if i had it to do over again.
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2talltechie (03-09-2015)
12-08-2011, 10:34 AM
#13
Ford didn't offer a 3:31 Limited slip last year or I would have purchased it. Want to simulate a taller gear? Lock the truck into 5th gear. Poof. A much taller gear.
The remark of better control on snow and ice doesn't ring true in my experience. Rock crawlers, maybe, but I don't know about that sort of thing. What I know about is snow and ice.
The remark of better control on snow and ice doesn't ring true in my experience. Rock crawlers, maybe, but I don't know about that sort of thing. What I know about is snow and ice.
12-08-2011, 05:50 PM
#14
Senior Member
I have that exact combo and 17" wheels. I only tow my landscape trailer (5x10 steel open trailer) and occasionally my Foreman 500 4-wheeler. Truck does good on gas, will see when I upgrade my wheels to 20's how it does. Right now with winter gas I am averaging 17-18.5 combined driving.
03-05-2015, 09:06 PM
#15
Junior Member
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I can't tell u how much I love the 3.5 ecoboost. ..2014 xlt ...4x4..and love the truck...I have 7000 miles on the truck and love driving it every day...live in phx,az ..and have a ton of red lights stop and go..and love that you don't have to smash the gas to get going up to speed ...the truck just takes off..!...great gas mileage for a truck with that kind of power..! Any ways ..just saying it the best truck on the market. ..
03-05-2015, 09:57 PM
#16
Senior Member
I got the 3.31s and 33s, truck still hauls the mail. The EcoBoost motor is a blast to drive. This truck gets up and goes. Really it does. I haul around two polaris 850xp quads on a flat bed trailer, around 3000lb total. I get up to 75-80 like its nothing.
Noww my mpg did drop when I added the tires, I still get around 20 if crusing the freeway with no traffic, but soon as it's stop and go and get into the city it goes down to like 15. I don't really care cause it such a fun truck.
Gears now are a lot different than when it really mattered 10 yrs ago. These 6 speed trannys have a pretty low 1st gear. the trannys from 10 yrs ago (old 4-5speeds) vs now is huge advancements.
Noww my mpg did drop when I added the tires, I still get around 20 if crusing the freeway with no traffic, but soon as it's stop and go and get into the city it goes down to like 15. I don't really care cause it such a fun truck.
Gears now are a lot different than when it really mattered 10 yrs ago. These 6 speed trannys have a pretty low 1st gear. the trannys from 10 yrs ago (old 4-5speeds) vs now is huge advancements.
03-06-2015, 06:51 PM
#17
Happy Camper
I have a bone stock 2013 Eco Screw 4x2 XLT, with 3:31 gears, and 18" wheels. I tow a 5200 lb travel trailer several times a year. Have had zero problems pulling the weight. Drops into 4th crossing the Blue Ridge at Fancy Gap, VA, but usually holds in 5 or 6.
As for normal mpg, I get exactly what the window sticker claimed, 16 & 22. Couldn't be happier.
As for normal mpg, I get exactly what the window sticker claimed, 16 & 22. Couldn't be happier.
06-22-2015, 07:48 PM
#18
Senior Member
I have a bone stock 2013 Eco Screw 4x2 XLT, with 3:31 gears, and 18" wheels. I tow a 5200 lb travel trailer several times a year. Have had zero problems pulling the weight. Drops into 4th crossing the Blue Ridge at Fancy Gap, VA, but usually holds in 5 or 6.
As for normal mpg, I get exactly what the window sticker claimed, 16 & 22. Couldn't be happier.
As for normal mpg, I get exactly what the window sticker claimed, 16 & 22. Couldn't be happier.
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Sirikenewtron (06-22-2015)
06-22-2015, 09:33 PM
#20
Senior Member
I was about to add a trans cooler, tbc and 7 pin plug but that got put on hold till end of summer. My truck has the 3.31 gears and no tow package, was kinda pissed at myself for not getting tow package but all well, is what it is. I'm only going to be towing around 5k travel trailer one or two times a year.