|In addition to the gasoline tank, the B 170 NGT has five natural gas reservoirs with a total capacity of 16 kilograms. Click to enlarge.|
Mercedes-Benz has introduced a new natural-gas platform in its revamped B-Class range: the B 170 NGT BlueEFFICIENCY. (Earlier post.)
The bi-fuel drive B 170 NGT can run on both natural gas and premium grade gasoline while delivering an identical maximum output of 85 kW (116 hp). Five natural gas tanks with a total capacity of 16 kg provide a natural gas range of more than 300 kilometers (186 miles). With the gasoline tank, the B 170 NGT has a total range in excess of 1,000 kilometers (621 miles).
Fuel consumption is 7.3 liters of premium gasoline and 4.9 kilograms of natural gas per 100 kilometers (32 mpg gasoline). The driver determines which power source the engine is run on at the touch of a button using the multifunction steering wheel; an electronic control unit carries out the switch instantaneously without any jolts.
The four-cylinder engine has been modified by Mercedes-Benz to include additional gas injectors on the underside of the intake manifold. A close-coupled pressure governor with an electromagnetic shut-off valve regulates the supply of natural gas and keeps the pressure within the system constant.
The installation of the gas reservoirs, which are located in the rear and underneath the front passenger footwell, reduces the trunk capacity of the B-Class by 128 to 422 liters (as per the VDA measurement method).
On the NEDC cycle, the CO2 emissions when running on natural gas are 17% lower than in the gasoline-powered B 170 at 135 g/km. If the 4.9 kilograms (7.5 m³) of natural gas consumed per 100 kilometers by the new B 170 NGT BlueEFFICIENCY is converted into the equivalent quantity of gasoline energy, the fuel cost per kilometer is around 50% less than when running on gasoline, according to Daimler.
Mercedes engineers have also, for the first time, compiled a full lifecycle analysis for the natural-gas vehicle. Assuming a total distance travelled of 150,000 kilometers (93,205 miles), overall CO2 emissions are some 20% below the figure for the comparable gasoline-engined model. NOx emissions are 11% lower, and CO emissions are down 54%. The greater ecological cost of the manufacturing process for the new B 170 NGT is balanced out after a distance of 17,300 kilometers (10,750 miles).