What tires do you have? I have learned that even your mood affects the mpg on these lol. If I'm in a hurry it goes to crap!

 

Just arrived in Florida after a 2 day run from Verona Ontario Canada. 1400 mile trip at interstate speeds 65 - 75 we averaged 16.9 mpg (U.S. gallons) . Coincidently with this low mpg the liters per 100 kilometers works out about the same. Also I stepped up to mid grade fuel so I think we did OK for fuel.
(5.4 , 3:55 gears, 20 inch wheels, ls and 4 wheel drive) Oh if this cold down here continues may I can go 4 wheelin' thuough the snow! Southern folks are such a bunch of Mary's when it comes to cold.

 

I got stock wheels and tires. Bridgestone 265/70/R17

 

I have a 2001 Screw with 175,500 miles with BFG All terrains (285-75-17) and I get about 14 on the highway and about 11 in town. Not the greatest, but if I wanted good gas mileage, I woulda bought a Prius

 

mine gets 17 hwy and 14 city not bad for a 5.4

 

08 SCrew 4x4 5.4L 3.55 ls, stck 255/65r17 tires, Hi-Liner Snugtop shell/cap: around town I get around 11.9 mpg. Freeway it depends on speed: @55 mph when I truely baby it, it is around 19mpg. @70 mph it is around 16mpg. I don't 'baby' it enough.

 

2001 5.4 Supercrew. 12 city and 17-21 highway (70mph). This is using Canadian gallons (4.5 vs 3.8 litres).

My work truck is a 2009 4.6 Supercab and the mileage varies between 12-20 mpg. Last week I got 14 highway pulling a trailer with 2 quads. I do lots of logging road miles in it with 1/2 in 4WD and get about 13.

I had a 4L V6 Ranger at work and in the bush the difference was 3 mpg.

 

Supercrews come stock with gas mileage?!?! I need to go to dealership and see if they can install that on my truck lol

 

14.8 mpg. mostly city driving.

 

17mpg highway. 15 mixed. 2wd with 5.4 and 145K miles now.

 

my 4.6L gets about 15 around town a 19 on the highway when i'm not flooring it.

my mods are a spectre cold air intake, side exit exhaust straight from the cats out before the rear tire, 3.73 gears, and stock tune. will be picking up an SCT xcal3 from a friend shortly. hopefully i will see a slight increase

oh and i have 285/60R18 bridgestone dueler H/L's on 18"x9.5" '99 lightning rims with a 2.5" leveling kit

and i have a spray in bedliner....not sure if that decreases mpg since it adds weight or not

 

13 City, 17 highway and around 14-15 mixed

Lowest was 12.8 and i run 87 all the time

2.5" HBS leveling kit, 35x12.5x18 mud grapplers, edge evo on level 2, afe stage II intake, magnaflow muffler before passenger tire

FX4 Screw. Weighs in at 7200lbs

Stock i went from San Diego to Vegas and got 520 miles on the first tank around 70 with a few hard runs to break her in. Havent gotten close since and im trying to swap out for the stock intake with headers and efans

 

with the 5.4l w/edge, 4:56 yukons, and 37s on 20s i avg bout 12.5 - 13 city and 14.5 -15.5 and sometimes 16 hwy. thats usally cruisin bout 60-62 @ 1800rpms. and a flat stretch are far and few around here

 

I get 17-18 around town and about the same on the highway. I actually can get upwards of 20 if im easy on her. Custom tunes are gr8! Need to get some 4.56s and see how much better I can get

 

I have been getting 15-16 around town. 2007 5.4 with the stock BFG's on it and 3.73: 1 gearing. My trip computer says 15.2 but my calculations have been .4-.5 mpg higher. My 99 4.6 only got 12.5 so anything better than that is a plus.