Fordlover wrote:
Saying the OBC always lies is outdated and wrong. But it's a good idea to run the numbers yourself ocasionally to check it. IIRC, the Dodge's were known to be way off a several years ago, but I'm sure that's changed.
Seems to depend on the make and the year, I suppose. My Dodge Durango was so far off (often 2-3 mpg) that I never even looked at it anymore. It also got to 147* ambient temperature on a sunny day! That display was useless ...
My '07 Subaru was also consistently 1.5-2 mpg off on the average reading. My last 3 GMs have been 0-.5 mpg off of hand calculations, and my F150 has been spot on so far.