What passenger airplane has the lowest fuel efficiency? What is the airplane with the lowest fuel efficiency? To set some parameters, let's limit it to the following:


Must be manufactured between 1960 and modern day.
Must be a non-military passenger airplane.
Must use liquid fuel (100LL, Jet-A, etc.)
Can be a commercial aircraft or GA airplane, but must be manned and have passenger seats. No helicopters!
Spacecraft don't count! (You know you were thinking of this)
Must be in the highest standard seat count configuration for the airplane. You cannot take a large jet like an A380, and remove all of the seats save for one!


Fuel efficiency is calculated in pmpg (Passenger miles per gallon), which is the total miles per gallon of the aircraft, divided by the maximum number of seated passengers. This does not include pilot, copilot, or any associated crew as passengers.

Please link back to credible sources, and show how you arrived at your pmpg in terms of mpg and passenger count.
TU-144 =  9.78 passenger mpg

TU-144 figures found on another forum, from an official flight planning document:
https://www.airliners.net/forum/viewtopic.php?t=1355819#p19483811

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By comparison the TU-104A = 15.88 passenger mpg

From an old Aviation Week story on the TU-104:
http://aviationweek.com/blog/tupolev-104-harsh-proof-rapid-soviet-progress-1956

Using that article and assuming 0.8 l per kg and 20% reserve, imperial gallons. These figures (especially TU-104A) are rough and would vary by loading and flight profile.