query: How many miles per gallon did Charly's Perethian's motorcycle achieve at the 1983 challenge?
answer: A motorcycle designed by Charly Perethian with a 185 cc Yamaha motor achieved 372 miles per US gallon (0.632 L/100 km; 447 mpg‑imp) at the 1983 challenge, and is now displayed in the Smithsonian.