I am very dissapointed in the accuracy of the overhead computers that state the mileage, MPG, etc. I have a F-350 crewcab dually diesel 4X4 and the truck is getting 12.2 - 13 miles per gallon, however the computer reads 14.2 MPG and does change when driving no matter what the actual MPG is that we are getting.
The 14.2 MPG on the computer also doesn't correspond with the distance til empty mileage listed on the computer.
The dealer has told me that the accuracy of the computer is 10% below or above the actual.
Does anyone know anything about the computers or if the dealers are not liable to fix these problems?

 

There's a TSB out by Ford stating that the console is only for temperature and the compass. The MPG readout and miles to empty are for the V-10 or 5.4 V-8 engines only and don't apply to the PSD. Just another option that was either deleted or doesn't function as represented when ordered. My truck is the same way.

 

I have a v-10 and your right it dosen't seem to give an accurate reading

 

After veiwing yourm message Igot the owners manual out it statyes that to reset the coumpter you must press the two buttons simultaneously I tried that and after a couple of times it seews to be giving me more accurate readings I know notice that the figures change as the way I drive as anybody had this experence

 

The read out will change depending on how drive for a specific distance. I believe the indicated MPG on the computer is an average of the latest 100 miles. If you reset it, it will produce almost instant readings.

My F350, PSD does not have the instaneous fuel economy feature. The truck was assembled in Nov 98, but the owners manual says it should have it. The dealer says that this feature is only for the gassers.

 

I have a 99 Super Duty Lariet with the 5.4L gasser that was assembled in Oct. 98, and my overhead computer does NOT give instant fuel mileage readings. There are times when I wish it did.

 

When you press both buttons at once it resets and gives you instant mpg. Just for yucks reset it when going down a long grade you'll get better milage than a Geo Metro.

 

I noticed when doing the instant mpg reset when coasting down a 6 mile long grade that the mgp tops out at 99 mpg. Pretty good for a v-10.

BTW on a 3000 mile trip completed yesterday I averaged 13.8 mpg. Trip went from Minneapolis MN to 10K msl in the Colorado Rockies and back.
Pat

 

fwiw, I have a '99 F250 SD V10 gas auto and my overhead console is pretty accurate on MPG compared to my manual calculations.

No instant MPG -- except the reset trick.