enjoy it, but do not rely on panel mpg

i experienced more than couple times that the japanese car panel mpg was way higher than pen and paper caculated.  toyota and nissan seemed inflated the nunmbers the most.  today i drove 300 miles with nissan versa.  the panel mpg showed 33.6, but i calculated with total mileage divided by the gas i refilled, it's only 26 mpg.  prius was another car i found having inflated mpg.