Is there a way to calibrate the indicated MPG so that the reading is more accurate? My indicated is optimistic by about 6%. Over about 3000 miles the indicated is 15.04 and the calculated is 14.21. Granted this is not great mileage but my truck scaled at 8970#.


2011 F350 6.7L CC KR 4x4 Dually

 

no way to change it sorry.

 

mine seems to be a bit more optimistic when I "top off" the tank. I started letting the nozzle cut itself off, stopping there... and it's only off by about 1-2%. Pretty good considering it's an estimate

 

It's about as accurate as your fueling process. Can you guarantee that you are filling the tank to within ounces of the same capacity every single fill-up? Highly unlikely.

Filling up at the same pump every time, I have found like djjoshuad said that the fill capacity is relatively consistent and fills pretty close to full at the click of the nozzle. My 6.0 was a nightmare to get completely full. If I let the nozzle click off by itself and hang it up at that point, my hand calc has been within an acceptable deviance from the in-dash meter. My 6.0 was much the same way.

 

On a 35 gallon fill-up, 6% is 2.1 gallons not ounces.

 

mine is off about .5 mpg each tank which after tank after tank would not show itself each time if it was a difference in fueling. I checked it fueling it to the point of having diesel actually run out the filler. anyways .5 mpg is way better than the 4+mpg my old dodge was off.