Photos: Racing at 6,786 miles per gallon Summary: At the European Shell Eco-marathon, it's the best fuel efficiency that wins the race. By Bill Detwiler | July 20, 2006 -- 14:45 GMT (07:45 PDT) Follow @billdetwiler Previous | Next Image 14 of 15 solar energy This vehicle received a boost from its solar energy panel. Topic: CXO Kick off your day with ZDNet's daily email newsletter. It's the freshest tech news and opinion, served hot. Get it.