I got 618 once. 2007 Audi A6 Avante. MPLS to Princeville, IL (just out of Peoria). Driving to the inlaws. Still had enough to get to the gas station up the street. Put in 20.6 gallons in. I told my (then) wife. I have to try, we have come so far. She was not as impressed as I was. Oh well.