Transport operator EMT in Madrid, Spain, has ordered 82 Mercedes-Benz Citaro NGT (Natural Gas Technology) buses. The order includes 40 Mercedes-Benz Citaro natural-gas-powered 18m articulated busesand 42 Mercedes-Benz natural-gas-powered rigids with a length of 12 meters.
The new Citaro NGT with natural-gas engine is approved without restriction for the use of renewable natural gas to DIN 51624. This makes for an even smaller carbon footprint. In addition, the noise level of the natural-gas engine is noticeably lower than that of a comparable diesel engine—depending on the driving status, noise emissions are up to 4 dB(A) lower.
The centerpiece of the new Citaro NGT is the 7.7-liter Mercedes-Benz M 936 G natural-gas engine. The natural-gas engine is based on the state-of-the-art OM 936 turbodiesel engine. The vertically installed six-cylinder in-line mono-fuel engine runs on compressed natural gas or biogas.
It has an output of 222 kW (302 hp) at 2000 rpm while delivering a peak torque of 1200 N·m (885 lb-ft) consistently from 1200 to 1600 rpm. In many instances, it undercuts the Euro VI emission limits by a considerable margin, According to Mercedes-Benz.
In the main driving range, output and torque characteristics remain consistent from idle speed to around 1500 rpm. Above this, the natural-gas engine actually delivers a slight advantage in terms of power and torque compared to the diesel. CO2 emissions of a natural-gas engine are up to 10% lower than those of a diesel engine. Using renewable natural gas to power the bus makes the carbon footprint even lower.
Western Europe’s urban-bus market amounts to around 10,500 new registrations a year on average and remains steady at this level. The European segment for urban buses with natural gas drives currently accounts for just under 1,000 units a year. Mercedes-Benz expects this number to increase further in the future.
EMT Madrid has a fleet of 1920 buses. The buses cover just under one million kilometers each year while transporting 425 million passengers.