279L / 100km or 120gal / 100mi.

[LDB]

I was watching an episode of Combat. A tanker said his tank used 4 gallons of fuel per mile. I thought that sounded too high and looked it up. The M4 Sherman tanks weren't such fuel hogs. They just sip fuel using only 1.2 gallons per mile.

[Draigflag]

Seems crazy, but when you look at how much they weigh, it's surprising they move at all, nevermind at the speeds they do.

[trollbait]

NASA's crawler-transporter has that beat with 296 liters per kilometer (125.7 U.S. gal/mi).
https://en.wikipedia.org/wiki/Crawler-transporter