While electric cars get a lot of press, electricity is hardly the only way to power vehicles without using gasoline.
Discussion of natural gas as a vehicle fuel is rising again, in part due to huge supplies coming online in North America.
Now Mercedes-Benz has launched its latest vehicle powered by the fuel, with the rather cumbersome name of 2014 Mercedes-Benz E 200 Natural Gas Drive, in its native market of Germany.
It's a bi-fuel car, meaning that it can run on natural gas or gasoline--making it more practical for longer-distance and varied use patterns than a fully natural-gas vehicle like the 2013 Honda Civic Natural Gas sold in this country.
The natural-gas E-Class mid-size luxury sedan uses a 156-horsepower four-cylinder engine that's been adapted to run on either natural gas or gasoline.
The car switches automatically to gasoline when the 121.5 liters of natural gas, stored under high pressure, runs low. It's also fitted with a start-stop system that switches off the engine, on either fuel, when the car is at rest.
Running on natural gas in the European test cycle, the bi-fuel E 200 emits just 116 grams of carbon per kilometer. When it switches to gasoline, that rises to 147 g/km.
Mercedes-Benz quotes a 0-to-62-mph acceleration time of 10.4 seconds.
Natural gas is considerably cheaper than gasoline in Germany, where the company estimates that if a driver covers 12,400 miles (20,000 km) a year on the gaseous fuel, the cost savings will be €1,000 (roughly $1,340).
Mercedes-Benz quotes a range of more than 250 miles on natural gas, and another 560 on gasoline--or another 744 miles if the buyer chooses to fit an optional 80-liter (21-gallon) gas tank.
The natural gas is stored in three cylinders: two under the trunk floor, and one behind the rear seat back. Despite this, the company says the trunk offers 14 cubic feet of cargo volume.
While the company notes that the E 200 Natural Gas Drive is the first bi-fuel vehicle offered in the luxury sedan segment, it has no plans to offer the natural-gas E-Class in North America.