Cruising by the Courts
Photograph by Harley Soltes, National Geographic
Building a homemade high-efficiency vehicle that runs on diesel fuel instead of gasoline is not an easy undertaking. Mass-market diesel-powered vehicles—more popular in Europe than the United States—get better mileage than gasoline-powered spark-ignition engines, due to their higher thermal efficiency. But it's hard in a school shop to duplicate the commercial designs, including turbo-charging, that regulate how air reaches the combustion system.
To increase their car's fuel efficiency, the ShopGirls have made plenty of tweaks, adjustments, and wholesale modifications since last year's competition, including changing the front brakes from mechanical to hydraulic so there will be less drag.
During this test run, driver Shante Stowell is practicing turning the car off and on to allow the car to roll some distance without burning fuel.
(Related: "Hybrid Cars Losing Efficiency, Adding Oomph")
Published April 7, 2011