The popular U.S. television show "MythBusters" investigated several fuel-saving devices using gasoline- and diesel-powered fuel-injected cars under controlled circumstances. Fuel line magnets, which supposedly align the fuel molecules so they burn better, were tested and found to make no difference in fuel consumption. The debunked notion that adding acetone to gasoline improves efficiency by making the gasoline burn more completely without damaging the plastic parts of the fuel system was tested, and although there was no apparent damage to the fuel system, the vehicle's fuel economy was actually worsened.