[Jackpine]

Originally Posted by 60DRB

I never "gun" the throttle. I don't leave the truck idling. I'm a "fuddy duddy" according to my family when driving. The tire size stock was 255-70/17 and the new tires are only one step larger at 265-70/17. All tire size, differential ratios, etc are set correctly. I just don't understand the large difference in mileage calculations. The mph is within 1-2 mph from the instrument panel and the Edge/Gryphon display. Performance (throttle response in all situations) is improved from stock. Actual mileage seems about the same as stock. It's just that the mpg reading on the Gryphon display is WAY off from reality. I think I'll just switch to one of the other displays so as not to be so annoyed at the unrealistic mpg claim/display.

I agree with that approach. I never found the Avg MPG values to be particularly accurate. But, my truck has a "message center" and it can show MPG too - again, the dashboard values tend to be higher than actual.

I've concluded there's a fault in the algorithm used for the calculation, or, a fault in the ability to sense the amount of fuel used vs distance driven.

I DO monitor Inst MPG though. If the number there is high, I know I'm getting good economy at that moment. At times, I've found by shifting out of OD (when towing) or locking the truck into 2nd gear actually improves my Inst MPG values.

- Jack