Not sure if this is the best spot, but didnt get any feedback on the superduty section and after all it is a 6.0
I have a 2006 F250 that I cant understand the MPG calculator on the dash. No matter where I go, what I haul or how hard I drive it never varies much from 13.6. I have even had the same thing when I tow my 20' enclosed trailer. I replaced the fuel gauge in February because it was having a dead spot and putting me in limp mode. but before that it was always at 13.6 or there close by. I have stock tires, no suspension mods or anything I can imagine that would affect the calculations. I have even gone so far as to have the speedo check to verify speed and distance as being close to actual. When I calculate it by the pump and a calculator, I am in the 16.5 area.. Any ideas? I have reset the dash and it starts at 12 and then makes it to 13.6 or 13.7 and thats it.

Thanks for any ideas.

 

We call those things the Lie-o-meters. The only way to calculate is by hand.

 

I actually had a fuel computer on my 04 truck that was pretty close. It was never over 1 mpg off of a hand calculation. YMMV

 

Do you reset it at each fill up. My 02 Dodge manual said the mpg meter quits when it reaches 600 miles. Or if you never reset it will give the lifetime mpg but prolly way off.

 

IIRC, my Ford owner's manual said that the reading is your total average since the last time it was reset. That would imply that it keeps counting indefinitely, though I would have expected it to be a decaying average over perhaps a couple thousand miles. It also said that the number of miles until empty is a decaying average, I want to say over the last 500 miles. This is all from memory for my 04, I could be off a little.

I've also found that the meter is always within a couple tenths of the hand calculation (I calculate every tank) whether I'm empty or towing, and I have a SCT tuner as well.

 

What he said

and do you leave the vehicle running when filling up ?
Know it will confuse the fuel gauge, wonder if it messes with the mpg....

I have the overhead, not the in dash,
and try to reset it each fillup when I care about mpg (rarely !)...

but I can report is that mine is actually very close now that I have 110k miles on the truck...

 

How do you reset the overhead MPG meter? I can't figure it out for the life of me...

 

I presently own an XL f350 but I remeber pushing 2 buttons at same time and hold a few seconds on my 2000 F350 lariat.

 

Yes, that's how you reset it.