|Vehicles that run on natural gas instead of
gasoline are called natural gas vehicles (NGVs). There are about
130,000 NGVs on our nation’s roads today and over 2 million
worldwide. More than 40 different manufacturers produce NGVs.
passenger vehicles are available today that run on natural gas
that has been compressed into special high-pressure cylinders to
get more volume into a smaller amount of space (called
compressed natural gas, or CNG). CNG is available at special
fueling stations. There are over 1,300 NGV fueling stations in
the United States.
Some vehicles run on CNG only, and others can run on either
CNG or gasoline; these are called bi-fuel vehicles. Some
long-haul trucks and transit buses run on a different form of
natural gas called liquefied natural gas, or LNG, which is made
by refrigerating natural gas to condense it into a liquid.
The liquid form is much more dense than natural gas or CNG,
and thus has much more energy for the amount of space it takes
up. So, more energy can be stored in the same amount of space on
a car or truck. That means LNG is good for large trucks that
need to go a long distance before they stop for more fuel.
Here is how NGVs work:
- NGVs burn natural gas that is compressed and stored in
- When the engine is started, natural gas flows into a
- The gas then enters a regulator where its pressure is
- The natural gas feeds into the engine through a fuel
injection system where it’s combined with air. The fuel/air
mixture is adjusted to burn most efficiently and with the
least possible emissions.
- Natural gas burns in the engine just like gasoline.
- NGVs can be refueled by attaching a hose at the fueling
NGVs are a popular transportation choice because they run
cleaner than other vehicles. Compared to gasoline- or
diesel-powered vehicles, they produce much lower levels of
pollutants and cost less to maintain. Also, natural gas costs,
on average, one-third less than conventional gasoline at the
The tanks used to store natural gas can withstand crashes and
heat far better than most gasoline tanks can. In the event of a
crash, natural gas disperses into the air, whereas gasoline
pools on the ground, creating a fire hazard.