The bigger the trailer, the more gas you are going to use. Your eco boost
is probably set up for best mpg without towing. On towing it can reduce
your mpg in half, and might not be good for the truck. I have a Toyota
Tundra with 5.7 engine, and I tow my Ranger around on a 12 single axle
trailer, and hardly see any reduction in mpg. I also can hardly tell it is
behind me. The towing is related to your trucks engine, transmission,
and its rear end gearing.

 

The ecoboost is a towing engine. It's has 365hp and 420ftlbs. These engines are torque monsters. Pulling up a grade there is no other 1/2 truck motor i would rather have. The engine starts to build boost at around 1600rpm so it's likely that cruising down the highway unloaded your not building boost. But cruising down same road at same speed with loaded trailer you are building boost. In these direct injection twin turbo motors
boost+more power=less mpg

 

I also gave a ecoboost 2011 with 3.31 rear diff.
I pull my 2015 full size ranger on a 5 x10 steel single 3500# axle. I get around 14mpg on the highway about 65 to 70 mph. Any higher than 70 cuts mpg down alot. I slightly modified my trailer by widening the wheel wells a bit.

 

I feel a lot better about my 14 mpg average spending most of its time pulling a 30' tandem dual wheel trailer. Gross wt loaded is 35,000 lbs on a 2500 Chevy.

 

If your pulling @ 75-80, your going to get your worst mileage. If you must pull @ those speeds then you definitely want 2 axles. A tire failure on a single axle @ those speeds can be catastrophic, you could end up on that All-State commercial--your getting sued by 12 different people/ whose your insurance co.

When we were pulling a fully loaded (3 ATV's) 16' trailer up to Tennessee, there was 5-6 mpg difference between 65 and 75 mph with a Duramax.

 

When I bought my Ranger I wanted an enclosed trailer because I didn't want it exposed to the elements while I was towing. Plus I was hoping to do a little better with gas mileage. Only because of the wind resistance? I had to have one custom built because of door height problems. It's a Homesteader Challenger. I went with a 14'x7' V-nose tandem axle. I had to add a foot in height. The trailers dry weight is 2,020lbs.. The Ranger with cab and acc. is about 1,500lbs. or so. So I'm towing around 3,500lbs. give or take. I tow it with an '11 F150 Lariat Supercrew 4x4 with the 6.2. She has the Stainless Works long tube headers and full exhaust, and I'm also running her on a SCT Livewire. I ordered this truck in Oct. of '10 and took delivery in Jan. '11. Everybody told me to go with the Ecoboost. But I'm a V8 guy. From my home in Delaware, I tow about 265 miles to my place in Burlington, West Virginia. The first half of the trip is relatively flat, but the last half of the trip is all mountains and hills. I usually travel a steady 60mph. on the highway. The trip regularly averages 11.5-12 mpg. On flat sections in good conditions I can do 13.5 mpg or so. I can't say if having an open trailer would be better or worse, But for what I have I'm pleased.

 

I also have an EcoBoost F150 4x4 but I don't have an enclosed trailer. I have a 7x18 Big Tex and I average 14mpg with my Ranger and RZR on it. I also have a single axle trailer but to be honest I've never bothered to check the fuel consumption with that one.

 

5.0

Never bought an eco boost because of this, had a 2011, 2013 and now 2015 4X4 F 150 and always average 13 to 14 mpg when towing my ranger or 23' boat.

 

Tandem should pull easier than a single.........

 

It takes power to pull weight, and turn tires. A tandem will pull harder than a single, and a tri axle will pull harder than a tandem. An enclosed will pull harder yet bc of wind. Speed also makes a major difference. The tailgate on these little trailers make a big difference also. I gained 2 mpg by taking it off. My trucks sweet spot is 72 mph. At that speed the egt r perfect, engine temp is all happy, and I get 9.5 mpg pulling my 5th wheel with the ranger on a trailer behind in triple tow style. But if I go 75mph, I lose 2 mpg and am down to 7.5 mpg.

 

I have a 2011 ford f-150 w/ eco boost and tow a 6x12 single axle with either a kubota tractor of my FS 2015 Ranger and get at best 13-15 mpg. I agree with others, a tandem axle trailer will weigh more and thus yield a lower mpg.

 

If the trailer you are towing has a vertical expanded metal loading ramp your mileage will be greatly effected and not because of weight, but air resistance from the expanded metal ramp.