Generac natural gas-fueled generators feature automotive-style spark-ignited engines that are more readily available in high volumes, making them more cost-effective components to source than similarly sized diesel engines. A key benefit to natural gas fuel is long running time. Because natural gas is supplied by a utility, refueling is not an issue. And not only do natural gas-fueled engines emit fewer nitrogen oxides and particulate matter than comparable diesel-fueled engines, but they avoid the fuel containment, spillage, and environmental concerns associated with storing diesel fuel.