I tested fer 2 month, 1999 e350 reg van, 3.55 gears, 4r100, curb weight 1/2 tank fuel with me in it 6,700 lbs....keepin rpm below 2500, 67 mph on highway...... i get 16mpg city and 20 highway.

 

02 F350 CC LB DRW 4x2, 3.73 axle, auto. Get about the same mpg under similar conditions.

 

03 F350 CC LB SRW FWD 3.73; Think is 16 highway 12 towing TT, but I quit counting.

 

no way, ur runnin bout 7800 lbs, u should get 14 city, 18 highway

 

Truck weights right at 8k, but at 69.999 mph (thats a small hair below 7000rpm) I think I'm gett 16, I should recalc since I got rid of the mud terrains and put these Michelin A/T's on. Might of gone up some.

 

Who, me? Cat scales recently put my truck, with no passengers and 1/2 tank of fuel, at 7,140 lb. If it were a 4x4, it'd be closer to 7,800.

Example trip from mid-Alabama to central KY. First 125 miles at 55-65 state highways, next 75 miles or so at 70 on the interstate, then dropped back to 65 for the remaining 300 miles. Arrived at destination with trip computer showing 20.3 mpg. Filled up the next day and verified that was accurate to within a couple of tenths (hand-calculated at 20.1).



Trip back, same speeds for same distances but with about 600 lb. of stuff in the bed. Pulling into the driveway said 19.8 mpg. A tad windy most of the trip back.

That includes the hills of northern TN and southern KY on I-75.

My "city" driving is mostly rural, so I manage to plug along in the mid 18's on a normal basis. I've seen 16.8 - 17.3 when having to spend a lot of time in town (we have really long stop lights).

 

7,000 rpms at 70 mph ?

 

1999 SD F250, ext cab, 8" bed, 8,000 pounds, 7.3, 6 speed manual, 3.73 rear, 305/70 tires..............19 mpg with the motor turned up on I-10 here in Louisiana........22 mpg sightseeing in the rockies in Colorado with the motor back in stock tune. 12 mpg towing a travel trailer with the aerodynamics of a parachute or a brick turned sideways. All this with 278,000 on the odometer

 

My 2002 350 shortbox crewcab at 72 mph and almost 2200 rpms is getting 14.4. That's four hundred miles into it and nothing but. A quarter city driving and three quarter straight flat road cruise control on 60 is 16.2 mpgs and the best I've ever gotten is 18.8. All hand calculated. Although lie o meter was never far off by .3 or .4. I have a superchips tuner, a 6637 air filter kit setup with the big boost air filter, a four gauge pillar pod and that's it besides a 3:73 rear end with 4x4. and recently my mpgs have dropped 1 mpg to 2 mpgs so I highly suspect a clogged epbv tube. I cleaned it out about 8 months ago, but still suspect the tube for for these 13.9 and 14.2 attrocities. Stop rollin so much coal, clean your epbv tube, get the right tire set up for mpgs, take care of boost leaks and these should get you right around 14 to 17 mpgs. Anything above that is an above average, highly maintained work of art. Which is what I consider mine everytime I turn that key and it fires up light its never been touched god blessed america and god blessed these 7.3's.

 

I weigh in at 7050lbs and on 285/75/r16 Cooper Discover STTs I'm seeing 14-16mpg.

Rustbucket (Ford F-350 Super Duty) | Fuelly

2wd trucks get a few MPG more. But... then they lose that fuel efficiency in winter when they're idling in one spot so the driver doesn't freeze while they wait for a 4x4 to come pull them out of wherever they're stuck at.

 

'02 F350 Service truck weighs in at 13,000 Lbs and I can nurse 14 MPG @ 55 MPH and @ 70 it drops down to 12.

 

2000 F250 4X4 extended cab 8' bed with 3.73 rear end and 240K. New manifolds, up-pipes, collector (old ones leaked), 50K on turbo, 60e DP-tune, HD4R100, big air filter... but 3" exhaust (ran out of cash). 700-mile round trip to Montana (75 MPH and 70 MPH) gave me 17.25 MPG (calculated)... and this was before tuner and new exhaust. With new exhaust/tuner, 16.99 city/highway combined and no black smoke - ever. My liedometer says 19.2 on that last test. I have a long road trip in a month and will test the highway miles.

 

I change the oil twice a year, regardless of mileage, only God knows how it was maintained before I aquired it a year and a half ago. Everything on it is original, cept for the Turbo (I think) I check the oil every two weeks, if I think about it. "Highly maintained" ? Not this truck.It gets no special treatment. 19 mpg is what it averages, everytime I check it down here (sea level) I suspect those that are getting 13-14 are mostly automatic transmission trucks, although I haven't really read thru to see. That's the main reason I turned away from an auto truck, I passed on a 99 that had 100K fewer miles, but it had an automatic, it was only a matter of time before I'd have to fork over 3-4 grand to go thru the trans. Great thing about the manual is clutches will last forever, if you do not abuse em and shift without using it. I spent $500 on a new clutch, flywheel and pressure plate a few months after buying the truck, I figure that's all I'll have to do to that part of the drivetrain for another 10 years.

 

I have 2001 350 four door long bed with large tires and a small lift (and ranch hand bumpers front and back ) ...hand calculating I average 14.5 to 16.5...mostly highway miles at about 75 mph.

 

I guess I'll have to see what my stock 6-speed will do, seems to like fuel but I'm comparing it to a 4cyl car. I'd be happy with 20 MPG.