Since natural gas (methane) has long been a clean, economical, and readily available fuel, many industrial engines are either designed or modified to use gas, as distinguished from gasoline.
Kuna maagaas (metaan) on alati olnud puhas, ökonoomne ja kergesti kättesaadav kütus, on tööstuslikud mootorid disainitud kasutama just gaasi mitte bensiini.