Airliners beat cars in fuel economy, especially on longer trips. That would not be news to attendees at recent Electric Aircraft Symposia, where speakers like Ilan Kroo, Stanford University professor and aircraft designer, have brought that message home. One of Kroo’s slides, shown below in a 2009 lecture (It’s nearly an hour, but worth a look and listen), lists a “narrow-body” airliner (in this case a Boeing 737-800) as able to fly one passenger coast-to-coast on 29 gallons of fuel, at about 81 passenger miles per gallon. A person carpooling his or her four-passenger Prius and driving responsibly could beat that (although not in the five hours required for the jet to make the total flight), but most trips are solo affairs, especially during commutes. Not anywhere near Green Flight Challenge efficiencies (403.5 ppmg for the winning Pipistrel G-4), such economies are improving with more modern versions of fuel efficient airliners. Cars are also gaining in fuel economy, prompted by government …