Picked up my new SuperCrew 4x4 w/ 3:55 and the short bed a few weeks ago , runs like a champ . Last week I made a 150 mile trip to pick up a 3926 lb travel trailer . On the trip up , I got 21.2 mpg running 70 up the interstate . On the way back on the same route , running @ 60 , I got 7.5 mpg. I took it into the dealer for another issue ( parking brake cable , which they fixed ) and asked the service writer about the mileage issue . His reply was that I "miscalculated " and for me to not pay any attention to the "instant mileage " display ( which I don't use anyway ) . Using my trip meters as well as manually calculating , I came up with the same #s .
We were scheduled for another short trip this weekend so I told him I would monitor the situation again and get back with him on Monday . A 200 mile trip , and a resounding 7.6 mpg . I went back in yesterday evening , he looked in his computer and said " Ford has no records of this problem , so just monitor it.... " I really didn't like that answer , so I went and talked to my salesman , and he said that didn't sound right to him either , and " I'll go talk to the service writer ... " While he was gone , I was talking to the guy in his office , who had purchased basically the same truck as mine @ a week before me , his truck has @ 500 miles less than mine on it ( mine is at 2,900 ) . He just got done with a 500 mile trip pulling a 3,000 lb boat and averaged 16.5 mpg .
The salesman returned and said the writer told him that " Ford does not even consider fuel economy issues until after 5,000 miles " . The truck does not run poorly , pulls the load with no problem , it just drains the tank to fast .
I could understand waiting out a 15-25 % discrepancy , but this big of a differential obviously indicates something is not right and I don't see why I should have to choose between refraining from doing what I bought the truck to do , or pouring my hard earned $$ into the tank until I each some arbitrary mileage point . Has anyone encountered this , have any ideas what could be causing this and where to go from here ?

 

Yeah that is about right. I get 18-20 mpg from my EB fx4 w/285/65/18 terra grapplers. Now when I pull my Polaris ranger on a 6.5x14 trailer I get around 10 mpg running 70-75. My mpg gets cut in half when I pull even a small trailer.

 

Thats a hard one, because there is very likely nothing wrong with the truck.
Here's pickuptrucks.com towing mileage on the ecoboost. http://blogs.cars.com/files/mileage-chart.pdf
I know they are running about twice the weight, but what you are pulling probably has more wind resistance.

This the the problem with turbo engines, it can get better fuel economy empty, but when you really get into the turbo, it will use the gas.

 

7.6 mpg is about right pulling a camper. My Screw with a 3.73 gets between 7 and 8 mpg pulling our 7,500 lb travel trailer. I know that this is heavier than yours, but the biggest issue with a camper is wind resistance. You are basically pulling a boat sail behind you.

 

I average 10-10.6mpg pulling my 32' 7500lb camper with the cruise set between 60-65mph. Something isn't right if your only getting 7.5mpg with only 4000lbs in tow.

 

That's kind of what I am thinking . I have worked for Cat for 35+ years , l

 

That's what I am thinking . I have worked for a Cat dealer for 35 + years , lots of turbocharged engines . I don't expect miracles , but have heard lots of reports in the range you mention . Even the chart posted earlier in this thread shows 8.5 with 5,000 lbs more than I am towing ( and a somewhat similar frontal area ) . Although I love the truck otherwise , if what I am getting now was what I was led to expect , I probably would not have purchased the truck. It pulls the trailer well , but at this rate of consumption that is irrelevant if I can't afford to take it on the road .

 

Would the dealer even be interested in doing a diagnostic for you? The MPG's on my truck increased a little as it aged but I don't have anything to pull so I'm basing this on empty traveling.

 

Just returned from a weekend of camping with our EB ... was 10.0 mpg to camp and return camp was 10.9 mpg.. 5ver cat scaled at 10k lbs. speed were 60-65 mph. I have towed this same 5ver and same route with 4 different vehicles (2v v10, 3v v10, 7.3L, 6.2L) and this truck as netted best economy of all.

 

Also would like to know how the Eco compared power wise against the other trucks??!!

 

Well the way I see it is - I personally would rather get around 10 mpg pulling a trailer every now and then. Also the empty mpg will be around 20 mpg vs the mpg of the other trucks mentioned will be close to or around 10 mpg before you hook up to a trailer.

 

My 5.4 gets 8-9 mpg towing around 6500, the ECO shouldn't be that low pulling that weight. Maybe try another dealer and see if they will check it and maybe re-flash it.

 

Most trucks get poor towing mpg , that is a fact we have to deal with. If I can get 18-20 mpg on prolly 25 of 30 tanks (example) and get around 10 mpg on the few tanks a year then I am happy with that.

 

I don't expect the same fuel economy towing as I do empty , nor anywhere near that . Having said that , the mileage I am getting towing almost half the weight of these examples listed here ( among MANY others I am aware of ) tells me that 7.5 mpg is NOT right . I am running 5-10 mph slower than these examples and should be experiencing at least a similar economy , indeed , considering weight and speed I don't think it is unreasonable to expect a little better . I don't tow that often , but when I do , I tend to tow long distances . 3 mpg ( or 4 , or 5 for that matter ) doesn't sound like much , but at $3.50-$4.00 a gallon over 3 or 4 thousand miles , it is a considerable amount of money . Last summer , we pulled our teardrop trailer on a 3-1/2 week trip from Austin , as far as Glacier Park , ended up logging 6,500 miles . That trip @ 7.5 mpg w/ 4$ a gallon gasoline would cost @ $3,714 . At 10.5 mpg - $2,476 , and at 12.5 mpg , $2,080 . That is a BIG difference !

 

I agree ! But I get around 10 mpg pulling my 6.5x14 single wheel trailer with my xp800 Polaris ranger.