The winner in that class got 2800 miles per gallon
Turkish, Sakarya University, was 4th, with only 1337 MPG.
The overall winner, France, LPTI St Joseph La Joliverie Nantes, got 8570 MPG, using Gasoline.
Sounds like the Turks should have gotten an award for best marketing though.
There little more than bicycles with 4 wheels, on a flat 3.7km track, doing 7 laps. Hydrogen has the highest energy, per pound of fuel. But, an extremely low energy per liter. Gasoline should be able to beat it, every time, it has a high energy per volume.
Diesel is the most efficient and cheapest fuel to produce we have. It will be in another 50 years too unless we make a push towards CNG, of which we have a 500 year supply in the Northern hemisphere.