Practical primer on EFI, diesel, propane, compressed natural gas and electric zero-turn mowing Click image to enlarge. It was hot. The little bit of coolness that had greeted the crush of rush-hour pedestrians had, by 10:30 a.m., been baked away, with not so much as a wisp of a cloud in the sky. This late June day in Washington, D.C., promised to be a scorcher. Even so, the National Park Service Going Green event at the Jefferson Memorial had to go on. The functionaries for the event, seemingly impervious to the morning’s oppressive humidity and heat, came dressed in business suits and in the case of Robert “Bob” Vogel, superintendent National Mall and Memorial Parks, in full park service uniform and wide-brimmed hat. Click image to enlarge. Martin Radue Fittingly, the event, which had the distinct feel of a coming out party, previewed the marriage of the two hottest trends in commercial mowing technology—propane-fueled commercial mowers featuring closed loop electronic fuel ignition (EFI) engines. About 40 well-dressed spectators sat attentively in metal folding chairs and politely listened as Vogel, Ron Flowers, executive director of the Greater Washington Region Clean Cities Coalition, and Roy Willis, president and CEO of the Propane Education and Research Council, gave short presentations extolling the National Mall’s commitment to “green” goals and the role of six new EFI, propane-fueled Exmark mowers in advancing those goals. Then, after a ribbon-cutting ceremony, prim and attractive WUSA-TV personality Andrea Roane ordered the six shiny Lazer Z S-Series zero turns ...