MPG Change

boatto5er

Founding VA Chap Ldr (Ret)
I've heard and seen stories about the Ford 6.4 Diesel getting better fuel mileage after a certain point (around 20,000mi), but have always been a little skeptical until now. On our recent trip to Arkansas (without the 5er:(), I got 16.3 MPG. On the return trip, I got 20.4 MPG. Same road, same weather conditions, same load. We did go over 20,000mi shortly after leaving my mom's house. We'll see how it goes over the next few fill-ups before reaching a final conclusion.
 

CrazyScotsman

Well-known member
Wish my 6.0 would get 10mpg running around town, this wewekend we pulled the Horn and drove a total of 300 miles, when I got home low fuel light was on, and was showing 4 miles to empty, the needle on guage couldn't get no lower in the red if I tried. Average mpg was 8.3 according to read out in truck.
This is one reason I am thinking about pulling the Horn with my Volvo, it averages between 7.5 and 8.1 mpg pulling a 53' trailer with a load. Not a very heavy load, but a lot more than the Horn weighs.
 

2010augusta

Well-known member
Wish my 6.0 would get 10mpg running around town, this wewekend we pulled the Horn and drove a total of 300 miles, when I got home low fuel light was on, and was showing 4 miles to empty, the needle on guage couldn't get no lower in the red if I tried. Average mpg was 8.3 according to read out in truck.
This is one reason I am thinking about pulling the Horn with my Volvo, it averages between 7.5 and 8.1 mpg pulling a 53' trailer with a load. Not a very heavy load, but a lot more than the Horn weighs.
You might have a problem, Our 6.0 gets an average of 9.0 with the Landmark in tow. And the only trip I did without the trailer was out to Indiana to get the trailer, and i got around 12-14 Mpg running at interstate speeds. This is right in line with what my '94 F-350 7.3 was doing after 215,000.
 

CrazyScotsman

Well-known member
You might have a problem, Our 6.0 gets an average of 9.0 with the Landmark in tow. And the only trip I did without the trailer was out to Indiana to get the trailer, and i got around 12-14 Mpg running at interstate speeds. This is right in line with what my '94 F-350 7.3 was doing after 215,000.

I have had this truck 3 years and fuel mileage has always been the pit's, not that I bought it for fuel mileage, best I ever done running empty was 14 mpg and best towing was going to Goshen rallye and that was 10.5 mpg a lot depends on the terrain, plus it has 4:10 rears.
Oh well, that's life.
 

2010augusta

Well-known member
I have had this truck 3 years and fuel mileage has always been the pit's, not that I bought it for fuel mileage, best I ever done running empty was 14 mpg and best towing was going to Goshen rallye and that was 10.5 mpg a lot depends on the terrain, plus it has 4:10 rears.
Oh well, that's life.

10.5 is not bad, I think my best is right about that too. The F-450 has 4:30 gears and highway truck tires. I don't know what the city and unloaded mileage really are because the truck is parked most of the time if the Landmark is parked. I have gone over three months without a refuel when we are camping in one spot. I agree that the mileage depends a lot on the terrain, but my best and worst tanks happened the same day on the "flat lands" between Marathon TX and Albuquerque NM this was almost all interstate driving. The fill up point was near Las Cruses NM. The difference between the two tanks was 10.74 to 7.35 mpg, I did not think the "hills" on I-25 would make a 3.5 mpg difference.
 

lcdrdean

Active Member
I've heard and seen stories about the Ford 6.4 Diesel getting better fuel mileage after a certain point (around 20,000mi), but have always been a little skeptical until now. On our recent trip to Arkansas (without the 5er:(), I got 16.3 MPG. On the return trip, I got 20.4 MPG. Same road, same weather conditions, same load. We did go over 20,000mi shortly after leaving my mom's house. We'll see how it goes over the next few fill-ups before reaching a final conclusion.

Are you sure you weren't going uphill on the way to Arkansas and downhill on the way back!
 

jmgratz

Original Owners Club Member
I hope you are right about better mileage on the 6.4. We have 6000 miles on ours and am getting 9 mpg towing the 5er and 12.5 not towing. We have the 3.73 rear end. I have heard it will get better. We shall see. The previous truck 99 F350 SRW with the 7.3 was getting 16-18 not towing and 10-12 towing. I know the newer truck may get less though as it is DRW 4x4. Oh well it is only money.
 

boatto5er

Founding VA Chap Ldr (Ret)
I hope you are right about better mileage on the 6.4. We have 6000 miles on ours and am getting 9 mpg towing the 5er and 12.5 not towing. We have the 3.73 rear end. I have heard it will get better. We shall see. The previous truck 99 F350 SRW with the 7.3 was getting 16-18 not towing and 10-12 towing. I know the newer truck may get less though as it is DRW 4x4. Oh well it is only money.

Jimj, I think you will get some improvements. We also have the 3.73 rear end and 4X4 and there's not a significant difference between the 250 and 350 weight-wise. The DRW proabaly lowerss fuel mileage a little, but not by a hugely significant amount. Back in the "low mileage days" we were getting 10.5-11 towing a Sundance and 16 or so not towing.
 

superduty08

Tennessee Chapter Leaders
My '08 6.4 has 27,000 and the mileage really hasn't changed much since new. I get 8.5-10 towing and 14-16 rural highway (small towns between). I don't think it will ever get what my '03 6.0 did at 21 mpg not towing at 70mph all interstate driving. My 6.0 got about the same towing as my 6.4.
 

Rrloren

Well-known member
I consistently get 17 to 17 1/2 around town with my 6.7 Dodge, hand calculated.
Last summer we towed our old TT weighing 11m lbs. out West putting just over 6000 miles on and averaged 13.1mpg. All but about 600 miles were towing.
Only towed the Sundance twice since getting it and saw 13mpg but not much Interstate driving , can't wait to get going in 2010 with several long trips planned.

I saw a 2 to 2 1/2 mpg improvement by unplugging the EGR valve about a year ago. Air intake improvement and a mild programmer may have helped also but the EGR unplug was significant. Don't know if that would work on the other make trucks.
 

caissiel

Senior Member
I had a GM 6.5L that did about 12MPG average since new. I had it checked by the dealer all the while it was on warranty and never improved. I bought a $3.25 boost fooler electronic pot and installed it across the Boost sensor and the millage just sored, and it was like having a new truck. Last millage was in the high teens, like 19 MPG most of the time even in city. I was convinced that the boost sensor had been sending the wrong signal to the Contols for 5 years. It could be a sensor giving wrong signal. All the 6.0L that I know do around 17 MPG empty, and 10MPG towing. There is a write up by Ford that 17MPG is the norm, and they would repair if under that.
 

jpjulian

Active Member
We have 38,000 miles, give or take a few, on our '08 6.4L and have yet to see any significant mileage gains. Since parking the BigHorn for the winter I am getting 11.6 mpg running around town and shorter trips. The best I've done without the BH in tow was just over 14 mpg on a 210 mile round trip. With the BH in tow we get ~9-9.5 mpg, sometimes a bit better, sometimes a bit less, terain, weather and speed considered. Poor mileage is my only gripe with this truck. Not so much as a squeak or rattle anywhere.

Joe
 
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