While the fuel is hugely popular in countries like Brazil, gasoline has always reigned supreme in North America. Or diesel, if you're a long-haul trucker--though that could be about to change.
Natural gas is already becoming a major power source across the U.S, but the trucking industry is quickly turning to its two major benefits--cleaner running and lower pricing.
The former is particularly important environmentally, given the billions of miles truckers drive every year delivering produce to each corner of the country. But as an industry that spends vast amounts on fuel, the potential for something cheaper is highly attractive.
Cheaper fuel, cheaper produce
The New York Times reports that natural gas fuel prices are as much as $1.50 per gallon equivalent cheaper than diesel. With eight million medium and heavy-duty trucks on U.S. roads, the savings for the industry would be enormous.
If you're wondering, "How does this benefit me?" then consider some of the products you use on a daily basis.
The vast majority of your food and other items--including the computer you're reading this on--probably reached you via a truck.
If that industry can reduce its costs by $1.50 per gallon equivalent, some of those savings can be passed on to the consumer--the whole supply chain becomes more affordable, so the cost of products need not rise as quickly.
Less foreign oil... less oil in general
The other benefits are even further-reaching.
The industry consumes three million barrels of oil per day, the equivalent of three quarters of the oil imported into the U.S. Roughly two-thirds of the diesel used as transportation fuel is currently used by three million 18-wheelers.
Swap some of those diesel vehicles for gas, and it means less money spent on imports, and more money kept inside the country--before you even consider the environmental benefits of using gas rather than oil.
Some way to go
So natural gas is perfect for the trucking industry, then?
Not just yet. For a start, Department of Energy figures suggest the network of filling stations is fairly small. Only 53 liquefied natural gas (LNG) and 1,047 compressed natural gas (CNG) stations pepper the U.S.--in comparison to 157,000 gasoline filling stations.
It's something which has hampered the adoption of natural gas in passenger cars too, but it's rather more important for truckers crossing the country than those who just need a filling station at the end of their street.
The number is increasing, but it faces an identical issue to any other alternative fuel--the "chicken and egg" issue of ensuring supply and demand for vehicles and filling stations is evenly matched.
Some estimates suggest that around a third of new heavy-duty vehicles could be natural gas-powered over the next few decades--though that's by no means a certainty.
There's also a risk the attractive price of natural gas could rise. Low price means high demand from other sectors too, pushing the price up and negating the cost benefits.
More sense than cars?
Ultimately, converting the trucking fleet to natural gas is more productive than doing the same for passenger vehicles.
The cost savings are more effective, as trucks use vastly more fuel on an individual basis--$1.50 per gallon is a much greater difference when you have a 200 gallon tank than it is with a 12-gallon tank.
Likewise, the emissions savings are greater per vehicle, even though fuel consumption itself is greater on natural gas than it is on diesel.
And while only one natural gas vehicle is currently on sale in the U.S, the Honda Civic Natural Gas, many commercial vehicles already use the fuel.
Fleets of commercial vehicles requiring natural gas will be more of a driving force for improving the natural gas filling network than the occasional passenger vehicle. Only half the existing network of stations is open to the public--the other half is already used by fleets.
If natural gas trucks start filling the roads then the stations will appear to accommodate them--and then the market for natural gas cars may increase with it.