MPG
Senior User
Joined: Aug 2009
Posts: 102
Likes: 0
From: MA
Hey, I can get 20 up a slight hill at the right speed. 
I agree with your post. For your own purposes, relative numbers are good enough, as long as the computer is consistent. But people across all type of platforms and their respective forums like to compare numbers and the argue whether or not they are comparable, which seems to require further testing.
I did try to top off the tank tonight, and it was really easy, as you guys said it would be. Much different from the old '04's tank. Filling up only 2.5 gallons, it took another quarter gallon to fill up and only took a minute to do waiting for the foam to settle. I can certainly see a 0.5 gallon difference at 20 gallons which I recorded last week, maybe more for a full fill up. Still not terrible, and consistency is more important. Either way, with the ease of which I can top off at the pump to a known location in the filler neck, I'm not sure how much value the gas jug test will add, unless it's to compare to the accuracy of the station's pump meter. I'm not sure that's ever been called into question, I've always assumed the meter was accurate enough. In the mean time I may just repeat the test of the last two weeks topping it off to at least remove the foam from the picture.
I agree with your post. For your own purposes, relative numbers are good enough, as long as the computer is consistent. But people across all type of platforms and their respective forums like to compare numbers and the argue whether or not they are comparable, which seems to require further testing. I did try to top off the tank tonight, and it was really easy, as you guys said it would be. Much different from the old '04's tank. Filling up only 2.5 gallons, it took another quarter gallon to fill up and only took a minute to do waiting for the foam to settle. I can certainly see a 0.5 gallon difference at 20 gallons which I recorded last week, maybe more for a full fill up. Still not terrible, and consistency is more important. Either way, with the ease of which I can top off at the pump to a known location in the filler neck, I'm not sure how much value the gas jug test will add, unless it's to compare to the accuracy of the station's pump meter. I'm not sure that's ever been called into question, I've always assumed the meter was accurate enough. In the mean time I may just repeat the test of the last two weeks topping it off to at least remove the foam from the picture.
Senior User
Joined: Aug 2009
Posts: 102
Likes: 0
From: MA
I forgot to post the results of the top off stuff. I found a while back that it's actually impossible to top off the tank reliably. It seems so at first, but I watched it for a bit and watched it drop slowly. I was able to stuff another 1.5 gallons or so in there before I got bored and gave up. With no good solution for that, there isn't much more I can do.
Senior User
Joined: May 2012
Posts: 331
Likes: 0
mileage - Yikes!
You should be getting way better mileage than that, especially if you are empty. I have a 2011 F-250 6.7 with 3.55 and just drove over 10 hours on a trip mixing city, stop lights, construction, and highway. I got 11.2 litre per 100 kilometres which equals over 25 miles per gallon. My highway speed varied between 100 to 110 kph, or 62 to 68 mph. (In U.S. measure that mileage is 21 miles per gallon) If I was getting your mileage I would try to find out why such a big discrepancy as most owners are getting better mileage. I have 134,000 kms on it and bought it new. I think most owners are getting close to 20 empty U.S.
Hotshot
Joined: Nov 2000
Posts: 11,591
Likes: 14
From: Pflugerville, tx
can't wait to see what the dually gets.
Sam
Senior User
Joined: Oct 2012
Posts: 151
Likes: 0
From: Terrell, Texas
in my 250 I was getting the same.. live 20 miles one way from anything. 9 miles rural, 11 miles decent road or highway.. over 13,000 the calculated average was 15.45. some towing, mostly not. (2000 of the 13000). Highway at 75 I was getting 18.7 - 19.5 depending on the wind. on Texas 35 you will get run over if you are under 75!
can't wait to see what the dually gets.
Sam
can't wait to see what the dually gets.
Sam
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Posting Guru
Joined: Sep 2009
Posts: 2,015
Likes: 4
From: Lakehills, TX
I forgot to post the results of the top off stuff. I found a while back that it's actually impossible to top off the tank reliably. It seems so at first, but I watched it for a bit and watched it drop slowly. I was able to stuff another 1.5 gallons or so in there before I got bored and gave up. With no good solution for that, there isn't much more I can do.
Realistically, that mileage isn't unreasonable for a slow and relaxed trip mostly on the flat highway. You don't say which cab and bed configuration, whether you have 4x4, which wheels/tires, or any of that jazz, which together can all add up to a mile or two more or less per gallon.
Hotshot
Joined: Nov 2000
Posts: 11,591
Likes: 14
From: Pflugerville, tx
also can't wait to tow a 5th wheel. we never noticed the 7,000 loaded enclosed car hauler with our 08 dually (other than the fuel gauge declining rapidly!)
Sam
Senior User
Joined: May 2012
Posts: 331
Likes: 0
mileage
This is part of the reason hand calculations aren't reliable, despite the best intentions of the people doing them and swearing by them. The best hand calculations still only come within about .5 mpg of the computer's injector measurements.
How do you know? Dash or hand calculated?
Realistically, that mileage isn't unreasonable for a slow and relaxed trip mostly on the flat highway. You don't say which cab and bed configuration, whether you have 4x4, which wheels/tires, or any of that jazz, which together can all add up to a mile or two more or less per gallon.
How do you know? Dash or hand calculated?
Realistically, that mileage isn't unreasonable for a slow and relaxed trip mostly on the flat highway. You don't say which cab and bed configuration, whether you have 4x4, which wheels/tires, or any of that jazz, which together can all add up to a mile or two more or less per gallon.
I have a 2011 F-250 crew cab 4x4 SRW FX4 with swapped out shocks. I have 20 inch rims with the stock OEM Michelins as mentioned. Tires are 65 psi and that mileage of 21 mpg US was on paved highway, some hills, and going through a number of towns....with lights and stop and go. Mostly though it was highway, on cruise control for 90 % or so of the trip. Truck was unloaded, one passenger. I don't think it is unusual mileage from what I read other owners generally get. Hey, I hardly hit any bugs on the windshield and grill which was a surprise. Must be the cool weather front we have been having. Oh, on the way back had some rain and wet roads. Quite pleased with the mileage. Had the truck since new, Dec. 2010 and drive a lot for business and pleasure.
Elder User
Joined: Feb 2004
Posts: 576
Likes: 0
From: Aromas, CA
i have a 2012 F-350 SRW XLT 4x4 with 3.31 gears. i do 150 miles a day over pacheco pass to work. if i set my cruise at 70-72mph, i will consistently get 19.5 mpg. 140 miles of highway, and about 5 miles of stop and go in town with traffic lights. on a recent trip down I5, did a tank of 100% highway and averaged 22mpg. very happy with this truck, was a huge improvement over the 6.4! but yes, gears make a huge difference, my friend recently bought the same truck with 3.55 and he has never seen over 18mpg