German version

In the new Lion's City Hybrid, MAN is presenting an innovative city bus at the IAA 2010 that will bring greater eco-friendliness and economy to urban mobility.

• Up to 30 percent lower fuel consumption and CO2 emission
• Quiet and free of exhaust gases when stationary and when pulling away from bus stops and intersections
• Significantly more efficient than the most modern conventional diesel-powered city bus, but just as safe and reliable

The Muenchner Verkehrsgesellschaft (MVG) Munich Transportation Company) has put the first MAN Lion's City Hybrid into service.

After years of research and development work followed by intensive testing in laboratories and on the road, MAN is now premiering the new Lion's City Hybrid. The innovative city bus is one of MAN's highlights at the IAA and can be ordered by customers in Europe with immediate effect.

Urban transport is the ideal sphere of operation for buses equipped with serial hybrid drive. Here, solo vehicles of up to 18 tonnes are driven at low average speeds, accelerating no end of times to between 40 and 50 km/h, only to slow down again shortly afterwards for a stop. When they decelerate, conventional buses transform their great kinetic energy to heat: the energy is thus lost. The innovative low-floor bus with serial hybrid drive on the other hand recuperates its braking energy and transforms it into drive energy. With the automatic start-stop system, the Lion's City Hybrid is able to reduce its fuel consumption and emissions even further. After all, city buses spend 25 to 40 percent of their operating time standing at bus stops or red lights.

The MAN Lion's City Hybrid is driven by two electric motors delivering 75 kW each, coupled by a summation gearbox. Together, the two motors produce a maximum torque of 3,000 Nm. This is why the MAN Lion's City Hybrid can do without conventional stepped transmission. The advantages: the bus accelerates powerfully from a standing start without any interruption of tractive force until it reaches the desired speed – this makes the ride more comfortable for the passengers and driving even simpler for the driver.

When the bus decelerates, the electric motors function as generators, transforming the braking energy into electrical energy. This is stored in so-called traction energy storage, consisting of six ultracap modules mounted behind attractively formed and aerodynamically optimised panelling on the roof of the Lion’s City Hybrid. Ultracaps, also known as high-power capacitors, have a number of advantages relative to the battery systems currently available: high power density, extremely fast power input, long cycle life, constant reliability and a high degree of efficiency. Unlike batteries, no chemical conversion is involved in charging and discharging - electric charges are simply shifted. The absence of moving parts and freedom from maintenance add to the high cost-effectiveness already being achieved. Memory effects and loss of power due to ageing are considerably lower in ultracaps than in lithium-ion or nickel-metal hydride batteries. Ultracaps have a much longer service life than battery systems. Operators of MAN Lion's City Hybrids will be spared the complicated and expensive process of exchanging the energy storage unit during the usual service life of a city bus (around ten years). This is one of the great advantages that the MAN system has over hybrid buses that use batteries for transaction energy storage. The fact that batteries deliver considerably less power at low temperatures than ultracaps is another aspect in favour of the MAN system.

When running on energy from its ultracap modules, the MAN Lion's City accelerates quietly and without emitting exhaust gases: depending on the operating conditions, this can be for a distance of up to two hundred metres. Once the energy storage is empty, the eco-friendly MAN diesel engine mounted at the rear of the bus cuts in automatically and with the help of a generator, produces the current needed for the electric traction motors. The Lion's City Hybrid uses a small-volume MAN six-cylinder diesel engine with a capacity of 6.9 litres and an output of 184 kW (250 hp) to produce electricity. This economical diesel engine with modern common-rail injection complies with the voluntary EEV emission standard and is equipped with a controlled CRTec® particulate filter that cleans the exhaust gas of up to 99 percent of its soot. The diesel engine is operated mainly in its optimum speed range with reduced dynamic performance.

Intelligent energy management keeps the driver continually informed of the system's charge status and its readiness for operation. The driver workplace developed by MAN, as well as the VDV dashboard which will be available as series equipment at a later date, have a central display showing all the data needed for efficient, stress-free and economical operation. These include instruments showing the charge status, the current degree of energy recuperation and general diagnostic information. The only difference to the conventional city bus with regard to the hardware is an emergency cut-off switch, whose installation is required by Directive 2001/85/EU on buses. MAN offers special introductory courses and training for MAN Lion's City Hybrid drivers so that they can fully utilise the energy advantages of the vehicle in day-to-day operation.

One of the first prototypes of the MAN Lion's City Hybrid was tested as early as 2001 on regular bus routes in Nuremberg, followed by practical operation in Paris and Spain. As of today, the MAN Lion's City Hybrid has done more than 100,000 kilometres. To produce exact data, conventional vehicles of similar performance and the same payload operated a reference service. The results showed savings of up to 30 percent in when operating on real bus routes. Moreover, the MAN Lion's City Hybrid had to pass the entire program of tests and trials that all MAN commercial vehicles have to pass in order to obtain series approval.

The new MAN Lion?s City Hybrid with its innovative EfficiencyDesign was presented at the UITP Congress at Vienna in June 2009 for the first time.

Photos, video-clip and text:
MAN Nutzfahrzeuge Group