HOW VEHICLES ARE EVALUATED FOR FUEL ECONOMY:
Fuel economy, or MPG, is measured under controlled conditions executed in a special laboratory. After performing a series of examinations specified by federal law, the OEM designers calculate MPG numbers for each pre-production prototype. Vehicle producers evaluate their automobiles and report the estimated outcomes to the EPA (Environmental Protection Agency). After the EPA reviews the results they retest the vehicle at the National Vehicles and Fuel Emissions Laboratory by running the vehicles through a series of driving routines also called cycles or schedules, that specify vehicle speed for each point in time during the laboratory tests. Once this is all completed and reported, the final number is then verified and released.