harrison14allen

My screen display of average mpg has been off anywhere from .2 to 1.1 mpg. It has never once been correct. I've heard of them being even more off but my mother has a 2011 F150 with the 3.7 and she gets about 22-23 and checks by hand and it's usually within .1

bigred90gt

My hand calcs, which have been done on every fill up in 26,000 plus miles, have consistently been 0.3-0.6 mpg less than the on board calculator. I reset my MPG and trip odometer every time I fill up.

doolyd

I hand calc every fill up and also reset the mpg computer every fill up and my computer is always off by at least 1mpg. I haven't really been monitoring it but I know it is off. I am going to start comparing but not sure why as there isn't anything I can do about it. It is off in favor of the computer, meaning hand calc shows less mpg....color me not surprised.

y2kmxz

Ive been hand calculating on my 2013 and the computer average is always 1.0 to 1.5 high.

Chrisj

Im going to remember to set the trip meter next fill up.....if the computer is no more than 1mpg off Ill still be happy. BTW I had a trip out yesterday and the computer ave readout went down to a couple points over 24. But it wasn't a steady reduction.....it went up some too so I know Im getting pretty good gas milage. Even if its 23mph Im happy with that