Natural Gas Vehicles
What is CNG?
Natural gas used as a transportation fuel is called compressed natural gas (CNG). That's because the gas is compressed to a pressure of about 3,600 pounds per square inch (psi) and stored in a fuel cylinder aboard the vehicle. CNG flows into the engine's combustion chamber and is ignited to create power to drive the vehicle.
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The Advantages of Compressed Natural Gas
The Environmentally Clean Advantage
- Compressed natural gas is the cleanest burning fuel operating today, producing the fewest emissions of any motor fuel.
- Dedicated Natural Gas Vehicles (NGV) have little or no emissions during fueling. In gasoline vehicles, fueling emissions account for at least 50 percent of a vehicle's total hydrocarbon emissions.
- CNG produces significantly less pollutants than gasoline.
- Tailpipe emissions from gasoline operated cars release carbon dioxide, which contributes to global warming. This is greatly reduced with natural gas.
The Maintenance Advantage
- Some fleet operators have reduced maintenance costs by as much as 40 percent by converting their vehicles to CNG.
- Natural gas does not react to metals the way gasoline does, so pipes and mufflers last much longer.
The Performance Advantage
- Natural gas provides the same mileage as gasoline in a converted vehicle.
- Dedicated CNG engines are superior in performance to gasoline engines.
- CNG has an octane rating of 130 and has a slight efficiency advantage over gasoline.
- Because CNG is already in a gaseous state, NGVs have superior starting and drivability, even under severe hot and cold weather conditions.
- NGVs experience less knocking and no vapor locking.
The CNG Cost Advantage
- Natural gas is cheaper per equivalent gallon than gasoline.
The Safety Advantage
- Surveys indicate that NGVs are as safe as or safer than those powered by other fuels. A 1992 AGA survey of more than 8,000 vehicles found that with more than 278 million miles traveled, NGV injury rates per vehicle mile traveled were 34 percent lower than the rate for gasoline vehicles. There were no fatalities reported--even though these vehicles were involved in more than 1,800 collisions.
The Financial Incentive Advantage