Natural Gas Vehicles (CNG Cars) FAQs

Where does natural gas come from?

Over 99% of the natural gas used in the U.S. comes from domestic or other North American sources. However, increasing demand for natural gas will require new supplies from non-North American countries, increasing our dependence on foreign sources. The Energy Information Administration (EIA) predicts that by 2025, more than 15% of the U.S.’s natural gas supplies will be provided from countries other than Canada and Mexico. Almost all of the today’s natural gas is fossil-based, non-renewable, and requires drilling and non-traditional extraction techniques that can be environmentally damaging. Biogas, or gas produced from plant material and solid waste, can be used in place of natural gas. Many municipal waste managers and local companies have begun capturing landfill gas to generate electricity or sell directly to commercial customers.

Which vehicles are best suited for natural gas?

There are currently more than 300,000 natural gas vehicles on U.S. roads today, including passenger cars and trucks, heavy-duty transit buses, school buses, and refuse haulers. According to DOE, over 10% of our nation’s fleet of transit buses and 20% of new buses on order operate on natural gas. There are a growing number of natural gas refueling stations, currently numbering over 1,500 across the country. Fleets that refuel at a central location are best suited for natural gas. However, manufacturers are planning on offering equipment to allow home refueling of vehicles, potentially expanding the market for passenger natural gas vehicles.

For passenger vehicles, natural gas also provides emissions benefits. For example, Honda’s 2004 Civic GX runs on compressed natural gas (CNG) was the cleanest federally certified passenger vehicle available, except zero-emission electrified vehicles. It is also one of a handful of vehicles including gasoline and hybrid electric vehicles that meet California’s strictest emissions standards. Another emissions benefit of natural gas vehicles is that there are no evaporative emissions during refueling.

What is the cost of a natural gas vehicle?

Because of low volume production, passenger natural gas vehicles tend to be about $3,000 to $6,000 more than equivalent gasoline vehicles, while heavy-duty natural gas buses cost about $30,000 to $40,000 more than equivalent diesel buses. Some fleet operators report that these costs can be recouped by lower operating costs, which are a combination of maintenance costs, fuel costs, and the fuel economy of the vehicle. Compared to diesel fleets, maintenance costs of natural gas fleets have varied widely across the country, with some fleets reporting lower or equivalent maintenance costs and others experiencing higher costs.

Historically, natural gas has been less costly than diesel and gasoline, but natural gas prices have been volatile over the past few years. The EIA estimates that natural gas prices may get some relief in the short term, but will continue to creep up over the next two decades due in large part to increased demand from new natural gas-fired power plants. Natural gas demand for transportation is also expected to increase significantly but is projected to remain well under 1% of total U.S. natural gas consumption. On average, CNG is expected to remain less costly on a gasoline gallon equivalent basis than diesel or gasoline.

Are natural gas vehicles safe?

Although both natural gas and diesel fuels are flammable and require special precautions and fire protection equipment, natural gas lacks some of the risks of diesel or gasoline. In fact, DOE reports that natural gas fuel tanks are much stronger and safer than either diesel or gasoline fuel tanks. Diesel and gasoline tanks can leak and contaminate groundwater, which is not a risk with natural gas. Diesel bus facilities often store much larger quantities of fuel on the site than natural gas facilities. And, while natural gas vapors are nontoxic, diesel vapors contain toxins that are dangerous to ingest or breathe.

Do natural gas vehicles help combat global warming?

It has been estimated that CNG (Compressed Natural Gas) vehicles using North American natural gas achieve greenhouse gas emission reductions within a range of 5 to 25% compared to conventional passenger gasoline vehicles. Use of non-North American natural gas would all but eliminate the greenhouse gas reductions because of emissions associated with transportation of liquid natural gas in large ocean tankers.

Are there other benefits to using natural gas as a transportation fuel?

Increased use of natural gas for transportation applications will require infrastructure investments, laying the groundwork for the future introduction of fuel cell vehicles. Experience with gaseous fuels and infrastructure can facilitate a transition to a future hydrogen transportation system. Also, demonstration projects are proceeding that use a blend of hydrogen and natural gas in transit buses, both reducing smog-forming pollutants and introducing hydrogen as a transportation fuel.