In an effort to save money on fuel costs, many Americans turn to electric vehicles (EVs), hybrids, and fuel-efficient small cars.
Electric cars seem to be the future, with nearly every major automaker planning to release at least one electric vehicle in the U.S. this year. However, EV infrastructure still lags well behind the framework supporting gasoline-powered cars.
Is there a third fuel that Americans could use to meet their driving needs?
Automakers have experimented with several during the past decade, including liquefied natural gas (LNG) and compressed natural gas (CNG). Why haven’t natural gas cars caught on?
Natural gas is a type of fossil fuel extracted from the earth. It’s mostly composed of methane. A natural gas car, also known as a CNG car (for compressed natural gas), is a vehicle powered by natural gas instead of conventional gasoline or diesel fuel.
In a natural gas car, the compressed fuel is stored in high-pressure tanks, which are typically located in the trunk or under the car. Once pumped into the engine, it powers the car — similar to a conventional gasoline or diesel vehicle.
Natural gas is a cleaner-burning fuel. It produces fewer greenhouse gas emissions and pollutants that contribute to smog and air pollution. Fleet applications are ideal for CNG since fleet vehicles tend to drive predictable routes and can refuel where they are stored. Most automakers also sell such CNG models to private buyers.
There are two different kinds of natural gas cars: liquefied and compressed. To turn natural gas into usable fuel, engineers must convert it into one of these more manageable forms.
Liquefied natural gas (LNG) is cooled into a liquid form for storage and use. It has limited use as a vehicle fuel because of the expense and complication of keeping it cool. Internal combustion engines can burn it instead of gasoline with just a few design changes, but storing it is challenging. It powers some long-haul trucks, but no company has yet made a practical way to store LNG in a vehicle small enough to serve as a daily driver for the average family.
Compressed natural gas (CNG) is gas that has been compressed into a much smaller volume. Internal combustion engines can burn it instead of gasoline. For a car to run on CNG, it needs a special fuel tank to store the gas under extreme pressure and a device called a fuel regulator that reduces the pressure as it enters the engine. These components are larger than a conventional fuel tank, meaning that CNG cars often have reduced trunk space compared to their gasoline-powered cousins.
Both forms of natural gas are generally less expensive than gasoline at current prices.
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CNG cars feel almost indistinguishable from gasoline-powered cars from the driver’s seat. They accelerate, turn, and brake just like you’re used to. They run quieter than gasoline-powered cars, though not as quiet as EVs.
CNG-powered cars are arguably better for the environment than gasoline-powered cars, as they emit less pollution. Studies vary, but most find that CNG-powered cars emit at least 20% fewer greenhouse gases than gasoline-powered cars.
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It is possible to convert nearly any car to run on CNG, but the process is expensive. The Clean Air Act requires you to have the work performed by a certified installer. Conversion costs start at around $6,000 and can climb as high as $12,000 for some engines. Gas prices would have to get much higher for that to be a practical economic decision for most drivers.
Natural gas vehicles produce fewer emissions and offer lower fuel costs, benefiting the environment and drivers. However, limited refueling stations, reduced range, and higher upfront costs have slowed their adoption, mostly restricting use to fleets and heavy-duty vehicles. Advances in technology and infrastructure could expand their appeal in the future.
Editor’s Note: This article has been updated since its initial publication.
