|Mercedes-Benz E 200 NGT. Click to enlarge.|
In parallel with its appearance at the Geneva Show, Mercedes-Benz’ new E 200 NGT BlueEFFICIENCY with bi-fuel natural gas drive is rolling out to European dealers. The basis for the natural gas engine is provided by the four-cylinder supercharged "Kompressor" engine with an output of 120 kW (163 hp). This has been modified with the addition of further injectors on the underside of the intake manifold and can run on either natural gas or unleaded premium-grade gasoline.
The output and torque characteristics of the four-cylinder power unit are maintained even when it is running on natural gas. In conjunction with a five-speed automatic transmission, the E-Class accelerates from 0 to 100 km/h in 10.4 seconds, while its top speed is 224 km/h (139 mph). Fuel consumption in gasoline-driven mode has been reduced compared with the predecessor model by 1.2 liters to 8.1 liters per 100 kilometers (29 mpg US), NEDC combined. In CNG operating mode, consumption could be reduced by 0.6 kg per 100 kilometers to 5.5 kg—corresponding to CO2 emissions of 149 g per kilometer.
Running on natural gas, the car has a range of around 360 kilometers (224 miles), while its standard 59 L fuel tank gives it a gasoline-driven range of around 730 kilometers (454 miles). Mercedes-Benz cites the advantages of running on natural gas as a reduction of around 10% in fuel consumption, a more than 20% reduction in CO2 emissions and significantly cleaner emissions than comparable models with gasoline engine only.
Along with the conventional gasoline tank from the standard model, four gas cylinders are concealed in the natural gas-powered vehicle—one behind the rear seat backrest and two underneath the floor of the trunk. They have a total capacity of 121.5 liters of natural gas (corresponding to 19.5 kg).
A pressure regulator with sensor and electromagnetic shut-off valve is fitted near the engine to regulate the supply of natural gas and maintain the required system pressure at a constant level. An engine management system ensures a smooth, jolt-free switch between modes even when the vehicle is moving.