No but you realize these are not NASA grade instruments . Are you not resetting the dash readouts at each fill up ? And are your checking your miles per gallon with pen and paper to see just how close the read outs are ?
One of my vehicles on the highway the readout is really close but in town only driving it is about 2 miles per gallon higher than actual .
Frankly you should be more concerned about the noise then the read out.