Natural gas vehicle designing the cylinders, compression ratios, and fuel injectors such that pre-ignition is avoided, but at the same time as much fuel as possible can be injected, become well mixed, and still have time to complete the combustion process during the power stroke. Natural gas does not auto-ignite at pressures and temperatures relevant to traditional gasoline and diesel engine design, thus providing more flexibility in the design of a natural gas engine. Methane, the main component of natural gas, has an autoignition temperature of 580C/1076F, whereas gasoline and diesel autoignite at approximately 250C and 210C respectively. With a compressed natural gas
Natural gas and some off-grid engine-generators use natural gas. Particularly high efficiencies can be achieved through combining gas turbines with a steam turbine in combined cycle mode. Natural gas burns more cleanly than other fuels, such as oil and coal. Because burning natural gas produces both water and carbon dioxide, it produces less carbon dioxide per unit of energy released than coal, which produces mostly carbon dioxide. Burning natural gas produces only about half the carbon dioxide per kilowatt-hour (kWh) that coal does. For transportation, burning natural gas produces about 30% less carbon dioxide than burning petroleum. The US Energy Information Administration