The engines for the new Mercedes-Benz Citaro are based on BlueTec diesel technology. The wide-ranging choice of engines for the Citaro covers the full spectrum of power requirements. The OM 906 hLA turbocharged diesel engine is a particularly compact and lightweight six-cylinder unit with a displacement of 6.37 litres, an output of 210 kW (286 hp) and a maximum torque of 1120 Nm. Alternatively, there is the OM 457 hLA six-cylinder engine with a 12 l displacement in a choice of two power ratings: 220 kW (299 hp) and 260 kW (354 hp) with maximum torques of 1250 Nm and 1600 Nm respectively. All of the engine variants stand out for their high pulling power from low rev speeds. This is of particular importance for enabling the bus to pull away dynamically in city traffic, even when full to capacity.
EEV emissions rating even without particulate filter
All engines are Euro V compliant as standard. The engines can furthermore be specified in a version that meets the most stringent voluntary emissions standard that currently exists – the EEV (Enhanced Environmentally-friendly Vehicle) standard. The new Citaro achieves EEV compliance by means of internal engine measures alone without the need for a particulate filter – further evidence of the enormous potential of the efficient, eco-friendly BlueTec diesel technology and its viability for the future. EEV with no filter means reduced costs for procurement as well as maintenance. Further benefits include the lower kerb weight and reduced space requirements, which in turn increases the number of seats. A particulate filter can, of course, be installed as an option. Power transmission is handled by fully automatic torque-converter transmissions made by Voith and ZF. The most up-to-date versions of both are fitted in the Citaro to maximise efficiency. With a choice of engine, transmission and matching final drive ratio, the new Citaro takes to the road with a customised drivetrain, just as its predecessor did.
Further reduction in fuel consumption
A new, electronically controlled air compressor is employed on the articulated Citaro bus with the vertically mounted OM 457 LA engine. This is an EAPU (Electronic Air Processing Unit) that combines the compressed-air drier, pressure governor, four-circuit safety valve and pressure sensors into a single component. The compact construction simplifies assembly and reduces the number of lines required. Where possible, the electronically controlled air compressor operates when the Citaro G is in overrun mode to save fuel. To ensure this is the case as often as possible, the system pressure for the suspension and door operation has been increased from 10 to 13 bar with the introduction of the new air compressor. This produces greater air reserves in day-to-day operation and saves fuel.
Detailed improvements to comfort suspension
The chassis on the new Mercedes-Benz Citaro again excels with exceptional comfort and handling safety thanks to its independent front suspension. In this respect too though, the new Citaro has now gone one better, especially from the driver’s point of view. The reworked steering has improved steering-wheel return, for instance – a key consideration for urban regular-service buses which have to turn so frequently.
Supreme safety levels thanks to innovative assistance system
A new assistance system is making its debut in the low-floor bus and in the Citaro simultaneously: for the first time, the Electronic Stability Program (ESP) is available for an urban regular-service bus. The Mercedes‑Benz Citaro is taking safety technology for urban regular-service buses into a new era with this innovative feature – thereby emulating its predecessor, which also set new benchmarks on its launch.