A gas engine is an internal combustion engine that runs on
gaseous fuel, such as coal gas, producer gas, biogas, landfill
gas, or natural gas. Gas engines refer to heavy-duty industrial
engines capable of running continuously at full load for
periods approaching a high fraction of 8,760 hours per year.
Gas engines, any of a class of internal combustion engines
that generate power by burning a volatile liquid fuel (gasoline
or a gasoline mixture such as ethanol) with ignition initiated
by an electric spark. They can be built to meet practically any
conceivable power-plant application requirements, the most
important being passenger automobiles, small trucks and
buses, general aviation aircraft, outboard, and small inboard
marine units, moderate-sized stationary pumping, lighting
plants, machine tools, and power tools.