Years ago one of these lusers approached my Prius at the gas station and authoritatively proclaimed,
He: "All that hybrid stuff is junk. You don't get any better gas mileage than my <I forgot what>!"
Me: What MPG do you get?
He: 32 MPG. But you don't really get any better! Your computer lies!
Me: Golly, you know everything! All I know is that I drive one and buy my own gas. Want to read my logbook of every fuel purchase? Also have a calculator (HP-41C is delightful overkill for a MPG calculator) if you need. This column contains odometer, trip miles, gallons purchased, cost, brand, $/gallon, the fool computer's claimed MPG, and finally the miles column divided by the gallons column.
Back then my first year averaged about 47 MPG but the 7 year average is just under 51.