Clean, quiet and efficient: Oldenburg opts for CNG city buses from MAN

“Every time the new MAN buses brake we benefit,” says Michael Emschermann, Chief Executive of Verkehr und Wasser GmbH (VWG) in Oldenburg. That’s because of an innovative development by the MAN engineers: the new MAN Lion's City 12 G EfficientHybrid has a crankshaft starter generator which recuperates the energy generated during braking and converts it into electric power. That means the MAN EfficientHybrid module helps significantly cut fuel consumption. “Also, the stop-start function installed as standard means the bus is virtually silent when waiting at stops and traffic lights,” Michael Emschermann adds.

The EfficientHybrid module’s intelligent energy management utilises the energy stored in UltraCaps – produced by recuperation when braking – to supply the vehicle's electrical system. As the stored electricity is also used while driving, the natural gas engine has to generate less energy, further reducing fuel consumption.

The Oldenburg public transport utility got together with local politicians and business representatives to explore what the city needed to do in order to be ready to meet the challenges of the future. That question was at the heart of the “Übermorgenstadt”, or Day-after-Tomorrow City, concept for which Oldenburg was awarded the official title of Germany's “City of Science” by the Stifterverband association for the promotion of science and humanities in Germany.

“The new MAN Lion's City EfficientHybrid perfectly fits the VWG’s philosophy too, because of its natural gas engine option, among other features,” adds Emschermann. Science to look at and touch is a trend that is also reflected in Germany's Science Centers. More and more people are interested in the application of science, and the stop-start function enables passengers in Oldenburg to really experience hybrid technology in action.

Local public transport operator VWG Oldenburg is a pioneer in natural gas technology, and is committed to sustainable mobility: in 2004, when the decision was made that only scheduled service buses powered by natural gas would be used in subsequent years, MAN already had a presence in the market with suitable vehicle types. VWG Oldenburg put 15 new Lion’s City 12 G buses featuring MAN EfficientHybrid technology into service in spring this year. It was four years ago that the company converted its entire fleet of 112 scheduled service buses to natural gas. It has been using bio-natural gas since 2013. “We are proud that Oldenburg has Germany's most environmentally friendly bus fleet,” says Michael Emschermann.

The 12.2 metre long Lion's City buses for Oldenburg are fitted with the 6-cylinder E1856 LOH natural gas engine developing 280 hp (206 KW) and the Voith D854.6 SensoTop automatic gearbox with retarder. The new natural gas vehicles with Euro 6 engines are virtually emission-free. That means air quality is significantly improved, especially in the city of Oldenburg. Another benefit is that the newly developed natural gas engines consume much less fuel than their predecessors. The bio-natural gas for the VWG fleet is produced from plant residues. These plants take the same amount of CO2 out of the air during their growth as is emitted during combustion in the engine. This means that VWG buses are almost entirely CO2-neutral. “By using biogas as fuel for our scheduled service buses, we as a public transport service provider are making an active contribution to climate protection in Oldenburg,” Michael Emschermann explains.

The natural gas buses in Oldenburg are saving some 9,500 tonnes of CO2 per year as a result. Efficient drives powered by alternative fuels are vital to the efforts being made to reduce emissions in city centres – and the new Lion's City series meets the needs in that respect with the MAN EfficientHybrid module incorporating many feature details. For example, a slight boost at idling speed improves the efficiency of the combustion engine.

The entirely newly developed MAN Lion's City bus not only looks modern, it’s also state-of-the-art in terms of economy, engine specification, driver's workplace and safety. "Everything about it has been rethought, and all the component elements combine perfectly,” Michael Emschermann enthuses. And because that is also true of the Lion's City 18 G, and MAN is continuously improving its vehicles, the articulated bus is undergoing driver trials with VWG in Oldenburg. That fits with the development of the new MAN Lion's City series, which has gone hand-in-hand with input from customers.