I really can't say as I don't drive my truck much empty on the road in fact I have had my truck almost 2 years and have just over 13000 miles on it. There was one time I got 17 MPG on the road but I was driving slower but there were still hills in it and some stop and go but I was really taking it easy on the go pedal

 

Just drove a couple hundred miles back from Houston TX, mostly interstate driving with speeds between 70-75mph and got 13.8mpg. The truck was empty.

 

Here is my first test of brand new 2012 6.2L F250 CC LB. This was round trip Cheyenne to south Denver and back. 65mph except in the city. I hand calculated as well and it's slightly off. I put 15.03 gallons in it which is 16.6 mpg. I filled at the same pump facing the same direction before leaving and on return.

 

Liftime average on the 6.2 is 14 over 20,000miles.
Lifetime average for the 5.4 is 15 over 26000miled

Epty the 5.4 is 1000lbs lighter plus the manual trans probably is most of the difference.

With the trailer the 6.2 gets alot better mpg and does a bit better on the hills. I do much prefer towing with a manual; and usually tow with the 5.4 unless i need the crew cab

 

Does it matter what type of fuel? I have run only E85 since I purchased my 2012 F250XLT FX4 6.2L in July. I now have about 2700 miles on it and only avg. about 10mpg. Is it really good to switch between fuels of 87 and E85?

 

E85 has less energy in it and gets less mpg than regular gas.

 

Start using 87 and you will see about 2 mpg increase. It may take 1 or 2 tanks to get all the E85 out. IMO the cost savings per gallon don't match up to the mpg decrease of the E85, so I just stick with the 87 and only use Shell or Mobil.

 

Sounds good to me. I will try that. Thanks for the input.

 

Also the manual states not to run more than 3 tanks of E85 in a row.

 

Thought I would update this. 1300 miles now and looks like daily average is going to be comfortably in the 14's. This is 2 mpg better than my 2005 5.4 F150 2wd when it was stock and new. I'm happy.

 

Just picked up my new to me 2011 F-250 CC Lariat FX4 w/45k miles. Drove 367 miles in my 2008 GMC Sierra 1500 w/DOD to pick it up and averaged 16.9mpg in the GMC on the way there. Picked up the F-250 and rolled out with a full tank of gas from Branson, MO to Omaha, NE and averaged 15.3 on the computer with 87. Did not do the math on return.

Mixed driving all week so far with 13.3mpg on 89 E10

 

618 mile trip including driving around Williston and Minot for a day and a half and averaged 14.8mpg hand caculated. Highway speed was 70mph and half of the trip into a headwind.

 

I have a quad cab with 3.73 gears been getting 12.8 city driving. Have seen numbers as high as 16.5 at 65mph. Took off all the exhaust up to first resinator then piped it to rear wheel, seems to me increased 2-3 mpg.

 

2012 crew 4x4 6 ft bed 18" wheels bed cover. Local around town12.0 mpg highway15 mpg
373 gears 9,000 miles synthetic oil

 

I just finished testing the same truck in XLT trim for ProPickup magazine. Unloaded. 15.4mpg @70mph over 200 mile run on I-10 flat interstate. No wind. Ideal weather. Pump figures--not onboard computer. 13.2mpg during 150 miles of city driving with light to moderate stop-and-go.