As noted in several threads the MPG calculations in the information display on our cars is wildly optimistic. I religiously reset the system at each fill-up and keep track of my real MPG in a log. In my car it looks like ithe display, on average, reads 4.5 MPG higher than real.

Is there a way to tweak any of the inputs into this system to provide a more accurate reading? Odds are, no, but if anyone would know it would be someone on this forum.