acadianbob

There are so many variable that contribute to the mileage you get that it is very difficult to compare. My experience is that if you get into the boost, the Eco will consume fuel. Other things that kill it: short-tripping, cold weather, lots of stop and go, extended idling.

I have an FX4, Eco, 3.73s, Max Tow. My average fuel mileage for the whole summer was 20.3 mpg; just about 4,000 mile average. I'm 60% highway and 40% mixed suburban driving. BUT, I accelerate modestly, time traffic lights, and hold my highway speed to 65 mph.

I can honestly say that, on flat roads and no wind, I get 21 mpg at 65 mph. Of course it all goes downhill from there. Wind, speed, load, etc all bring it down.

LastResort

I've got an XLT Eco MaxTow, stock, with a canopy and get about 16 or so. But I'm probably 80% city, use the throttle like a button and don't do a great deal of road trips. The best I've seen on a flat ish trip with some sections through small towns was 20 ish. I'm happy with that though.

jferg92

3:73's with bad mpg? Bigger tires: problem solved

SkiSmuggs

I rarely make short trips, cut the engine off for long construction stops and pretty much never go more than 5 miles over the speed limit and use cruise control a lot. My daily commute is 70 miles over secondary roads through the Green Mountains. In the summer months I average over 20 mpg and drop to 18 in the winter. I took a 1600 mile trip in 2012, mostly interstate and kept to the 65 mph speed limit. I got 21.5 for the trip.

ORCM

Since you have a '13, make sure you don't have any recalls. I had one on mine (built 5/25), which was a PCM reflash. The PCM wouldn't kick out of warm up mode, and would run rich all the time. After the flash, I gained about 1.5 to 2MPG. I get pretty decent MPG now.

rdkev

lol, what?

jferg92

EB owners with a light foot and 3:73's or 4:10's complain about crappy mpg, especially highway. Getting a larger diameter tire (not too heavy though) to numerically lower your effective ratio. Pull less rpms, better mpg, and looks better with a filled out wheel well. Win win

F-250,LD

Bigger tires raise the effective final gearing. If you raise the final ratio, it will rev lower at higher speeds and should increase MPGs on the highway. But they will also decrease towing capacity and may reduce low speed MPGs.

Bigger tires usually weigh more which can decrease MPGs too.

OP, I would expect that your setup should get better MPGs than that. Granted mine is not a max-tow, but I average about 17-18 (mixed) with my 5.0L.

lariut

I got the max tow 6.5 bed with eco boost and 3.73's. With stock wheels/tires I got 18-19 mpg 50/50 city/hwy.

With the raptor take off's (315/70/17), I get 16-17 avg mpg 50/50 city/hwy. What helped me was monitoring boost on my torque app. Stay out of boost and mpg's improve considerably. Downside is the truck is not as fun to drive like that.

Adobe2X

I have the same truck as the OP. Keep in mind that "winter" gas, cold temps and lots of stop and go driving will drop your mpg significantly.
During the summer I can get 18 mpg in town, but now that has dropped to 15/16 mpg. On the highway, I can get as high as 21.5 at 70 mph, but that has now dropped to 18/19 tops....
The EB is extremely thirsty accelerating up to speed --- you are trying to get nearly 3 tons back up to speed with only 214 cubic inches....
Coast up to red lights and remember that every application of the brakes burns gas to get back up to speed.