The world records for efficiency are here: https://www.fai.org/records?f%5B0%5D=field_type_of_record%3A1119 https://www.fai.org/records?f%5B0%5D=field_type_of_

The world records for efficiency are here: https://www.fai.org/records?f%5B0%5D=field_type_of_record%3A1119 https://www.fai.org/records?f%5B0%5D=field_type_of_record%3A... The world record for the 1000-1750kg weight class is about 16 miles per gallon. That is burning jet fuel rather than ordinary gasoline. 1000 kg is light for a modern car. There are no aircraft that can compete with a Prius for transporting small numbers of people. There are few that can compete with a Hummer. (Note that I'm not sure how the records are calculated. There are a lot of relevant variables, most importantly how fast the plane is flying. And I'm not an aeronautical engineer, just a hobbyist.) EDIT: More information on that record can be found here: https://lift.erau.edu/for-the-record/ https://lift.erau.edu/for-the-record/ I get a slightly different figure of 17-ish mpg. Still pretty bad.