The competition, which began in 2007 with 136 vehicles from 111 teams, required that the vehicles achieve 100 miles per gallon or the energy equivalent. While two of winning vehicles reached that goal with electric power plants, the top winner did it with an internal combustion engine.

“When you have a background in racing, you focus on what you’re trying to achieve, and you know that you have a given time period to do it,” said Oliver Kuttner, the founder and chief executive of Edison2 of Lynchburg, Va., which won the $5 million top prize with its Edison2 Very Light Car. The company’s fabricators and mechanics have worked for teams participating in auto races like the 24 Hours of Daytona and Indianapolis 500.