Compressed Natural Gas (CNG)


CNG is a readily available alternative to gasoline that’s made by compressing natural gas to less than 1% of its volume at standard atmospheric pressure. Consisting mostly of methane, CNG is odorless, colorless and tasteless. It's drawn from domestically drilled natural gas wells or in conjunction with crude oil production.

Natural gas powers more than 12 million vehicles on the road today. Unfortunately, only about 250,000 of these are being used in the U.S., according to GE. The average growth rate in the U.S. shows a 3.7% increase per year since 2000, as contrasted with a booming global growth rate of 30.6% per year.

Compressed Natural Gas Information about CNG



Image referencing CNG for article about Compressed Natural Gas for fleets and drivers interested in CNG fuel.

What is Natural Gas?

Natural gas occurs deep beneath the earth's surface. Natural gas consists mainly of methane, a compound with one carbon atom and four hydrogen atoms. Natural gas also contains small amounts of hydrocarbon gas liquids and nonhydrocarbon gases. We use natural gas as a fuel and to make materials and chemicals.

Why Natural Gas?

Natural gas powers about 150,000 vehicles in the United States and roughly 22 million vehicles worldwide.1 Natural gas vehicles (NGVs) are a good choice for high-mileage fleets— such as buses, taxis, and refuse vehicles—that are centrally fueled or operate within a limited area or along a route with natural gas fueling stations. The advantages of natural gas as an alternative fuel include its domestic availability, established distribution network, relatively low cost, and emissions benefits.

What is Natural Gas?

Natural gas is an odorless, gaseous mixture of hydrocarbons—predominantly methane (CH4 ).

How and where is natural gas produced and distributed?

Most natural gas is drawn from wells or extracted in conjunction with crude oil production.

Is Natural Gas safe for use in vehicles?

Just like conventional vehicles, NGVs must comply with all applicable regulations, including Federal Motor Vehicle Safety Standards (FMVSS).

How do NGVs work?

A CNG fuel system transfers highpressure natural gas from the tank to the engine while reducing the fuelpressure to meet the operating requirements of the engine’s fuelmanagement system.

How well do NGVs perform?

NGVs are similar to gasoline or diesel vehicles with regard to power, acceleration, and cruising speed..

What NGVs are available?

A wide variety of light-, medium-, and heavy-duty NGVs are available and suitable for various applications.

How can I find reliable and EPA-compliant vehicles?

All natural gas fueling systems must be certified to meet U.S. Environmental Protection Agency (EPA)or California Air Resources Board (CARB) emissions standards.

How much do NGVs cost?

The price of an NGV is higher than that of a comparable conventional fuel vehicle; however, NGVs can provide an acceptable return on investment (ROI) for many fleets because of the fuel’s relatively low price.

Is it easy to fuel an NGV?

CNG vehicles are fueled with easyto-use, pressure-sealed dispensers. The amount of time it takes to fill a tank depends on several factors, including how the fueling station is configured.

How much does natural gas cost and where is it available?

Historically, the average retail price of natural gas has been lower an more stable than that of gasoline and diesel.

How do I calculate the ROI for NGVs?

The ROI associated with natural gas depends on a variety of factors. Because natural gas fuel is often less expensive than gasoline and diesel, fleets with higher annual vehicle mileage will experience shorter payback periods. Payback is therefore linked to fleet size and type.

How do NGV emissions compare to other emissions?

All new vehicles are equipped with effective emission control systems and must meet the same emissions standards, regardless of fuel type.


Natural Gas Vehicles


Natural gas powers more than 150,000 vehicles in the United States and roughly 15.2 million vehicles worldwide. Natural gas vehicles (NGVs) are good choices for high-mileage, centrally fueled fleets. Compressed natural gas (CNG) tanks and safety are improving, and in many cases CNG can provide adequate range for the required vehicle application. For vehicles needing to travel long distances, liquefied natural gas (LNG) is a good choice. The advantages of natural gas as a transportation fuel include its domestic availability, widespread distribution infrastructure, and reduced greenhouse gas emissions compared to conventional gasoline and diesel fuels.

CNG and LNG are considered alternative fuels under the Energy Policy Act of 1992. The horsepower, acceleration, and cruise speed of NGVs are comparable with those of equivalent conventional vehicles. Also, compared with conventional diesel and gasoline vehicles, NGVs offer other air-quality benefits.

There are light-, medium-, and heavy-duty natural gas vehicles available from original equipment manufacturers, as well as medium- and heavy-duty vehicle options available through qualified system retrofitters. Qualified system retrofitters can also economically, safely, and reliably convert many vehicles for natural gas operation with aftermarket conversion systems.

Compressed Natural Gas Vehicle information on CNG Fuel


CNG Fuel System

Compressed natural gas (CNG) fuel systems require different maintenance than conventional fuel systems. Technicians should regularly inspect and replace the fuel filter, which removes any oil or contaminants in the CNG. This filter generally needs to be replaced annually by a qualified service facility; owners should check their owner's manual for the specific requirements of their vehicle. In some cases filters should be drained of any contaminants on a more regular basis, depending upon the application.



Image referencing CNG for article about Compressed Natural Gas for fleets and drivers interested in CNG fuel.


The United States used about 27.49 trillion cubic feet (Tcf) of natural gas in 2016, the equivalent of 28.4 quadrillion British thermal units (Btu) and 29% of total U.S. energy consumption.

Natural gas use by U.S. consuming sectors by amount and share of total U.S. natural gas consumption in 2016:

Electric power—9.987 Tcf—36%
Industrial—9.31 Tcf—34%
Residential—4.35 Tcf—16%
Commercial—3.11 Tcf—11%
Transportation—0.74 Tcf—3%


- About 96% of U.S. natural gas used is domestically produced
- Roughly 20% to 45% less smog-producing pollutants
- About 5% to 9% less greenhouse gas emissions
- Less expensive than gasoline


- Limited vehicle availability
- Less readily available than gasoline and diesel
- Fewer miles on a tank of fuel

Natural Gas is Clean

Natural gas is the cleanest commercially available transportation fuel.

Natural Gas is American

Ninety-eight percent of all the natural gas consumed in the U.S. is produced in North America, while nearly 55 percent of the crude oil we use is imported.

Natural Gas is Abundant

Domestic reserves of natural gas are estimated to be twice that of petroleum based upon current consumption—more than 100 years.

Natural Gas is Affordable

Natural gas has been 25–42 percent cheaper than diesel over the last 14 years; EIA’s Annual Energy Outlook projects that this favorable cost-spread will continue into the future.

Natural Gas Vehicles are Widely Used

Use of NGVs is widespread and growing—there are approximately 120,000 NGVs on U.S. roads today and about 15 million worldwide.