MPGs on 2010
 

unloaded HWY 14.5
City 12
Towing 8500 5th wheel 8.5-9.5
Only 3300 on truck since new F350 CrewCab 2WD SRW
Sound about right?:-newbie

yup...

ur unloaded HWY numbers are NICE...

2010 4x4 crew 4.10 auto 6.8, stock best was 13.5 highway,10 or so city,3'' lift and 33.7'' tires best highway is about 12.1 at 70 mph 9 to 10 city, towing 4000lbs nets 7.5 to 8 winter time high way same speeds. the other guy must drive very conservative to get those numbers esspecially towing over 8k!!

RE:
 

I thought lifts and big tires and 4X4 would account for those differences

How are you calculating your numbers? By hand or using the computer? My computer is always about 0.6mpg high.

Even running a 2wd truck, I'd say you're lucky to be getting those numbers. The highway seems reasonable, but the city seems high. I ran 20K miles my first year and averaged about 10.5mpg. Highway was in the 13mpg neighborhood, city was about 9mpg. I've seen a jump to about 11.2 the past few months which I think is the non-winter fuel.

Are you running one of the aftermarket tuner programs by chance? If not wonder how these might improve with something from Mike at 5 Star tuners?

Depending on the person city driving can involve a lot of high speed freeways that can give you higher mileage than others. It is the stop and go light to light traffic that is a killer.

No tuner just stock. Small town just 2 lights lots of secondary roads with 45-55 limits couple 25-35 school zones. Pretty much use it for hardware runs and towing the fifth wheel. Coming from 6.0 dually milage seems about 3mpgs less.

That's why your city MPGs are so good. I'm always stop-n-go in the city. It takes at least three lights for me to get anywhere.

I have a 5-star tow tune on mine and it makes the truck run great but hasn't helped the milage any!