My lowest MPG vehicles were
1. 1968 Chevy Chevelle SS 396, with lots of go fast goodies, 5-12mpg. Got Religon and started racing sports cars
2. 1970 Ford F100 360cid, 11-12 mpg. Sold when we moved on to a boat.
3. 1986 Mazda RX-7 15-32mpg. Seals shot if left sitting for two days restart took forever.
Highest
Tomos moped, MPG so high who cares. Filled every few weeks