• The world’s largest truck and bus fleet with hybrid drive
  
  
• World debut of the Mercedes-Benz Atego BlueTec Hybrid and Citaro G BlueTec Hybrid
  
  
• Trucks with parallel hybrid, buses with serial hybrid
  
  
• New Mercedes-Benz Citaro G BlueTec Hybrid: a technological trailblazer
  
  
• Orion VII HybriDrive: world market leader among hybrid buses
  
  
• Mitsubishi Fuso Aero Star Eco Hybrid: Asia’s first hybrid bus in series production
  
  
• Citaro with fuel cell drive system: two million kilometres
  
  
• Mercedes-Benz Atego with hybrid drive: weight-optimised
  
  
• Mitsubishi Fuso Canter Eco Hybrid: series successful, now to be launched in Great Britain
  
  
• Freightliner M2 Hybrid: electrically powered peripheral units
  
  
• Freightliner Van: reliable and economical, series production starting

Daimler is promoting measures for drastically reducing the emissions and fuel consumption of commercial vehicles. To mark the launch of the Shaping Future Transportation initiative, Daimler Trucks and Daimler Buses today presented 16 trucks and buses featuring alternative drive systems and fuels. The vehicles from Freightliner, Mitsubishi Fuso, Mercedes-Benz, Orion and Thomas Built Buses were exhibited at the Mercedes-BenzMuseumin Stuttgart, and included models making their world debut as well as vehicles that are already being used by customers. Hybrid technology plays a key role in these vehicles, as it can reduce diesel consumption by up to 30 percent, depending on the application.

Daimler is the global leader on the market for hybrid commercial vehicles, having delivered some 1,500 Orion hybrid buses, more than 100 Freightliner trucks, and 200 buses and trucks from Fuso. Added to this are 1,500 Mercedes-Benz trucks and buses that run on natural gas. As a result, Daimler has the world’s largest fleet of environmentally-friendly commercial vehicles in use by customers.

“Commercial vehicles are the force that’s driving economic growth and globalization. As the world market leader in this sector, we will therefore offer our customers vehicles that are even more economical and environmentally friendly in the future,” said Andreas Renschler, Daimler Board of Management member and Head of Daimler Trucks, at the presentation in Stuttgart. “The Shaping Future Transportation initiative demonstrates that we take our responsibility toward customers and the environment very seriously. The initiative encompasses all of the globally networked research and development activities in the area of alternative drives and fuels for all of the brands at Daimler Trucks and Daimler Buses. The Shaping Future Transportation initiative also demonstrates that the environmentally friendly commercial vehicles from Daimler are no longer prototypes, but real vehicles that are being used by customers.”

Daimler plans to employ alternative drive systems in additional vehicle models and regions, focusing primarily on hybrids. In North America, Freightliner will manufacture 1,500 M2 hybrid trucks over the next three years and also produce a hybrid version of a Thomas Built school bus. In the meantime, the second-generation Mitsubishi Fuso Aero Star Eco Hybrid will be launched on the market in Japan. In Europe, the first Mercedes-Benz Atego BlueTec Hybrids will be delivered to customers in Germany, France, and the CzechRepublicnext year. At the same time, customers in the UKwill be conducting a pilot project with ten Mitsubishi Fuso Canter Eco Hybrids. For public transportation needs, Daimler unveiled a three-axle articulated Mercedes-Benz bus with the designation Citaro G BlueTec Hybrid, which will go into series production in 2009.

Because of their decreased fuel consumption, trucks and buses equipped with hybrid drives also produce fewer pollutants and less CO2. Daimler is also investigating the possibility of using alternative fuels in order to preserve fossil sources of energy. According to the commercial vehicle experts at Daimler, the most promising fuels from renewable resources are vegetable oil-derived hydrated fuels (HVOs). Later, they will be joined by BTL (biomass to liquid) fuels. In cooperation with the oil company OMV and the vehicle fleets of two of its customers (DHL and SSB-Stuttgart), Daimler has now commenced fleet testing of HVO fuel in Mercedes-Benz trucks and buses.

Biodiesel (FAME) has been commonly used in Mercedes-Benz trucks for the past ten years. And Mercedes-Benz has been producing and delivering buses and municipal vehicles that run on compressed natural gas (CNG) for almost just as long.

Daimler’s diesel engines have evolved into high-tech drive systems. As such, they will remain the chief means of commercial vehicle propulsion for many years to come. Diesel engines still have great potential, as evidenced by their minimized emissions and continuously increasing energy efficiency. As a result, emissions of particulates and nitrogen oxides have decreased by more than 90% on average since 1990. Mercedes-Benz trucks and buses equipped with BlueTec diesel technology combine environmental improvements with economic benefits for the vehicle operator. That’s because BlueTec technology has led to further substantial reductions in fuel consumption. In the case of long-haul trucks, for example, the annual reduction amounts to around 2,000 liters of fuel or more than five tons of CO2 emissions. “We often talk of the 'three-liter car,'" said Renschler (a vehicle capable of covering 100 kilometers on around 3 liters of fuel. “However in comparison, Daimler already has the 'one-liter commercial vehicle,' if you take the high transport volumes into account.”

Hybrid technology represents a further milestone in the reduction of fuel consumption on the path toward achieving economically viable zero-emission fuel cell drives. Hybrid vehicles incorporate two different types of drive system: an electric motor and an internal combustion engine. The energy released during braking is recovered as electric power, which is stored in batteries until it is used again to propel the vehicle via an electric motor. Thanks to this additional drive system, diesel engines can be made smaller and lighter without reducing driving performance.

Daimler has decided to use parallel hybrids for its trucks. In parallel systems, the electric motor is incorporated into the powertrain, where it generally works in parallel with the diesel engine to propel the vehicle. Due to the way they are used, Daimler’s hybrid buses are equipped with a serial hybrid drive. In this arrangement, a generator directly connected to the diesel engine provides the energy for the electric motors. In addition, all of the auxiliary systems of the Mitsubishi Fuso and Mercedes-Benz hybrid buses are electrically powered, which makes completely electrical and emission-free driving possible for short stretches. The technological transition to the zero-emission vehicle is being ushered in by the Mercedes-Benz Citaro G BlueTec Hybrid, which employs an innovative drive concept featuring wheel-hub motors. In principle, future generations of the vehicle will only need to replace the diesel-engine generator with fuel cells, as the electric drive components have already been tried and tested.

Fuel cell vehicles have already proved their suitability for day-to-day operations in the world’s largest field test, which involved 30 Mercedes-Benz Citaro buses. The vehicles were driven more than two million kilometers in over 125,000 hours of operation. However, the fuel cells’ service life needs to be substantially lengthened and their cost drastically reduced before they can be used in series-produced commercial vehicles. These goals will remain a challenge for the development engineers for some time to come. Another difficulty is that the necessary hydrogen infrastructure still needs to be created.

Because hybrid vehicles cost one-third more than today’s diesel vehicles, economic aspects will play a crucial role in the acceptance of alternative drive systems by operators. Although the overall cost of ownership of hybrid vehicles is substantially improved by their fuel savings, incentives will be needed for at least a few years following the market launch. This is confirmed by the success of alternative drive systems in the U.S.and Japanthanks to government incentives. Fleet operators in Europedo not yet have such inducements to purchase a hybrid vehicle. "Environmental protection will only be effective in the long term, if it also provides customers with economic benefits,” said Renschler.

Daimler Trucks and Daimler Buses - Worldwide leaders in alternate drive systems

Around 3000 trucks and buses with alternative drive systems from Daimler Trucks and Daimler Buses are in day-to-day operation around the world. Hybrid-drive vehicles such as regular-service city buses by Orion and trucks by Freightliner in North America, the Mitsubishi Fuso Canter Eco Hybrid light truck and the Aero Star Eco Hybrid city bus in Japan, or fuel-cell-powered buses in Europe, Australia and Asia – they have all successfully won their spurs in terms of technology. No other manu facturer in the world has produced more commercial vehicles with alternative drive systems.

World debut for new hybrid vehicles

And yet this is only a start, for the Mercedes-Benz Atego BlueTec Hybrid and the Citaro G BlueTec Hybrid are now celebrating their world debut. The Canter Eco Hybrid is due to start its customer trials in Great Britain, and Freightliner is producing a series of 1500 hybrid trucks. They are all witness to the outstanding expertise of Daimler Trucks and Daimler Buses in the field of alternative drive sys tems, and are major steps on the way to the ambitious goal of the Zero Emission Vehicle.

With 1500 city buses in regular service, Orion is the world’s leading manufacturer of hybrid buses. More than two dozen step-in vans by Freightliner are already in operation in North America, and this number is set to increase to 100. With the Mit subishi Fuso Canter Eco Hybrid, Fuso has already produced more than 200 units of the world’s cleanest light truck, while Mercedes-Benz has successfully completed trials of 36 fuel-cell-powered buses on three continents and can look back on al most 40 years of experience with hybrid-drive commercial vehicles. And this is only a part of the impressive balance sheet of Daimler Trucks and Daimler Buses when it comes to developing alternative drive systems.

All vehicles have proved their worth in everyday customer operations

One of the major factors is that these are not just one-off experimental vehicles in clinical trials, but that these and other vehicles are in operation with customers and are demonstrating their everyday viability. The unrivalled worldwide expertise of the individual brands is networked: for example, Mitsubishi Fuso is the world centre of competence for light trucks with hybrid drive within Daimler Trucks.

Trucks with parallel hybrid, buses with serial hybrid

Joint developments have been created from this, together with the practical expe rience gained across the continents. Whatever the drive unit required for different vehicle sizes or brands, the engineers at Daimler Trucks have opted for a common architecture in their hybrid-drive system. With a view to costs, reliability and the technical parameters, Daimler Trucks is focused on parallel hybrid drive for all its vehicles. In this configuration the additional electric motor is located behind the engine and clutch, but in front of the transmission. This arrangement allows purely electric drive, and has proved to be the best compromise between design complexity, dimensions, weight and performance. At the same time, the truck remains mobile even if the hybrid drive fails, which enhances overall reliability.

The completely different operating parameters of city buses in particular have led Daimler Buses to decide in favour of serial hybrid drive in the USA, Europe and Japan. One characteristic of serial drive is the lack of a mechanical link to the drive axles. This technology makes the "bus stop function" possible, allowing the bus to pull up to bus stops, and pull away from them, ultra-quietly and without any emissions. The drive units can be accommodated almost completely independently within the vehicle, which is a particular advantage given the limited installation space available in a low-floor city bus.

Zero Emission goal, and depending on the interpretation this goal has already been achieved with hybrid vehicles over short distances.

World debut: Mercedes-Benz Citaro G BlueTec Hybrid

Daimler Buses has produced a technologically pioneering hybrid-drive system in the Citaro G BlueTec Hybrid low-floor articulated bus, which celebrates its world debut in Stuttgart. Equipped with serial diesel-electric hybrid drive, this allows emissions-free driving under battery power alone over short distances.

In the Citaro with serial hybrid drive, the four-cylinder diesel engine no longer acts as a continuous propulsion unit but drives the generator to produce electric power as required. This is then stored by maintenance-free lithium-ion batteries on the roof of the Citaro. The batteries are not only charged by the diesel generator, but also by energy regained when braking in a process known as recuperation. The actual drive to the wheels of the Citaro G BlueTec Hybrid is provided by four electric wheel hub motors at the centre and rear axles of the articulated bus. Even under difficult operating conditions, their total output of 320 kW is very generous for an articulated bus, and two driven axles also ensure superior traction. An intelligent operating strategy ensures that the power is distributed among the different com ponents in an efficient manner.

Citaro G BlueTec Hybrid is intended to cover half its route under electric power only

The recuperated braking energy obtained when approaching bus stops or traffic lights is used both to supply the vehicle at standstill and for moving off after a stop. This allows the hybrid bus to operate under electric power alone, and therefore prac tically without emissions, at bus stops, at standstill and when accelerating, accompanied by a significant reduction in noise. The aim is for the Citaro G BlueTec Hybrid to cover around half of a demanding inner-city route under electric power alone, without the diesel engine running.

Downsizing: a compact diesel engine is enough

Downsizing is one of the great advantages of the serial hybrid technology in the Citaro: instead of the large, 12-litre in-line six-cylinder engine usually installed in articulated buses, a compact 4-cylinder engine with a displacement of 4.8 litres and an output of 160 kW (218 hp) is sufficient. As a result the engine weight is reduced from around 1000 kg to just 450 kg or so.

As the diesel engine in the hybrid Citaro is not used as a drive unit, it is not required to deliver peak performance levels and can therefore operate very economically and ecologically, near its optimum operating point and within a narrow engine speed range. The bus is able to dispense with a conventional automatic trans mission, which improves efficiency and reduces weight at the same time. Owing to these downsized major units, the additional weight of the Citaro G BlueTec Hybrid prototype is only around one tonne compared to a conventional articulated bus with diesel drive, and further improvements appear possible.

Ancillary units such as the air conditioning compressor, steering servo pump and air compressor are no longer driven by the internal combustion engine, but individually by electric motor. This means a further improvement in efficiency, as all these units are only powered when they are required. Moreover, thanks to this elec tric power the ancillary units can be positioned almost anywhere, for example on the roof of the bus. This concerted opti misation of all the individual units makes the Citaro G BlueTec hybrid bus unique worldwide.

Up to 30% lower consumption

Depending on the type of operation, the developers expect the Citaro G BlueTec Hybrid to consume around 20 to 30% less fuel (expressed in litres per 100 km) than with conventional diesel drive. Despite the extra cost for the hybrid drive, which is around one third, the investment in the Citaro G BlueTec Hybrid should be amor tised within about six years. In addition to environmental aspects, economic con siderations therefore also play an important part in the development process. The bus will be able to demonstrate its potential in the coming year, when it enters customer trials in regular service. Series production is planned for 2009.

Next step: Citaro with fuel cell hybrid drive

The Citaro with hybrid drive is a logical step on the way to the fuel-cell-powered city bus. It already features a capable electric drive system and batteries as an energy reservoir, therefore only the diesel engine would need to be replaced by a fuel cell system. With these comparatively minor design modifications, the goal of practi cally emissions-free operation in inner city areas would be achieved – the Zero Emission Vehicle without particulates, nitrogen oxides or CO2, and with a very quiet drive system. The next step on this road is therefore obvious: the Citaro with fuel cell hybrid drive – a vision becoming reality.

The new Citaro G BlueTec Hybrid continues a great tradition and draws on nearly 40 years of experience in using alternative drive systems in buses: as early as 1969 Mercedes-Benz presented the world’s first hybrid bus in the form of the OE 302. It was followed by the OE 305, and then duo-buses like the OE 305 GTD and its successor, the OE 405 GTD. Mercedes-Benz supplied more than 200 of these models to the Ecuadorian capital of Quito, and around 50 units of the O 405 GTD were operational in Europe – indeed some of them are still in operation in Esslingen near Stuttgart. Other steps on the way to the new Citaro BlueTec Hybrid included the 0 405 NÜH, a low-floor inter-urban bus with wheel hub drive, a diesel engine and traction batteries, as well as the electrically powered Cito which was in series production from 1999 to 2003.

Orion VII HybriDrive: world market leader among hybrid buses

The hybrid buses produced by the American brand Orion are well beyond the tes ting stage. With its Orion VII HybriDrive solo, low-entry regular-service city bus, Orion has won tenders in numerous American and Canadian cities from New York to San Francisco since 2003. More than 1000 vehicles are now in daily operation, and together with orders yet to be completed the grand total is almost 1500 hybrid buses. This makes Orion the world market leader in this segment. The total fleet of Orion hybrid buses currently in operation covers a mileage of around 50 million kilometres per year.

The Orion VII HybriDrive has a serial hybrid-drive system. In the case of Orion the diesel engine runs constantly and transfers its power to a generator, which in turn supplies the electric motor and is located immediately behind the rear axle. Power is transferred to a conventional drive axle with a differential. The compact diesel engine transversely mounted in the rear has a displacement of 5.9 litres, generates an output of 191 kW (260 hp) and is equipped with a particulate filter. The electric motor has an output of 184 kW (250 hp), with even 235 kW (320 hp) possible for short periods.

Compared to diesel-powered city buses, and depending on the type of operation, the Orion VII HybriDrive achieves a reduction in fuel consumption of around 20% to 25%. Particulates are reduced by 90% versus a diesel engine with no filter, nitrogen oxide emissions by 40% and carbon monoxide by around 30%. Over its entire ser vice life, each bus saves 75,000 litres of diesel fuel and avoids emissions of four tonnes of nitrogen oxides and 195,000 kilograms of CO2.

Remarkably, these hybrid buses have proved to be more reliable than conventional diesel buses in New York. Thanks to their electric drive they accelerate more rapid ly and smoothly, with no jerking due to gearchanges. The operating life of the brakes is twice as long, and both the diesel engine and electric motor look set to have an extremely long operating life as well.

Mitsubishi Fuso Aero Star Eco Hybrid: new hybrid bus

The Japanese brand Mitsubishi Fuso, a member of the group, has also opted for hybrid drive in its city bus. Since as early as 2004, five Aero HEV vehicles have been operating successfully in three Japanese cities and have each driven around 150,000 km without problems.

The technical architecture of the serial drive is similar to that of the North American Orion: a diesel engine transversely mounted at the rear operates with an optimised characteristic map and drives a generator. This supplies two electric traction mo tors. These are located immediately behind the rear axle, and transfer their torque to a portal axle with super-single tyres via a power collecting gear. In this case the batteries carried on the roof are lithium-ion accumulators.

The development of hybrid buses is advancing in leaps and bounds: at the end of 2007 Mitsubishi Fuso presented the second generation under the name Aero Star Eco Hybrid. The completely redesigned drive system now uses a compact four-cylinder diesel engine with a displacement of only 4.9 litres. It has an output of 132 kW (180 hp) and serves only to generate electricity. This downsizing saves con siderably on both space and weight, and moreover also reduces fuel con sump tion even further. The generator driven by the engine in turn supplies the power to two electric motors each with an output of 79 kW.

When stopping at traffic lights and bus stops, the diesel engine of the low-entry bus switches off automatically. For this reason the doors and ancillary units such as the power steering pump, air compressor and air conditioning are now powered by elec­tricity only. The bus also moves off under electric power, the diesel engine not cutting in to generate power until a medium speed is reached. Kinetic braking energy is transformed into electrical energy and fed to the batteries (recuperation).

The Aero Star Eco Hybrid is available as a city bus with a 4800 mm wheelbase or as a suburban version with a wheelbase of 5300 mm. Passenger capacity amounts to 65 persons in both cases.

Mitsubishi Fuso presented a first battery-powered city bus back in 1973. In 1994 the company introduced a system to recuperate braking energy, and a further en vi ron ­mentally friendly vehicle was a natural-gas-powered city bus launched in the year 2000.

Citaro with fuel cell drive: two million kilometres

Hybrid drive in buses is a logical interim stage on the way from the internal com bustion engine to the fuel cell and hydrogen power, i.e. on the way to the Zero Emission Vehicle. Exactly ten years ago Mercedes-Benz presented the "Nebus" (New Electric Bus), the world’s first fuel-cell-powered bus.

At the 2003 UITP Congress in Madrid, Mercedes-Benz presented the first fuel-cell-powered Citaro, and findings obtained since then clearly demonstrate its practical viability. In the world’s most extensive practical trials with fuel cell vehicles, 30 buses based on the Citaro entered operation with transport companies throughout Europe for a two-year period. Three further vehicles were also in operation in Australia for two years, and another three fuel cell buses are operational in the Chinese capital Beijing. In some cities the European trials were even extended for a further two years. No less than nine of these buses are currently in operation in Hamburg, with a further three in Amsterdam.

All in all, these vehicles have covered more than two million kilometres and accu mu­lated a total of 125,000 operating hours. With an availability of 90 to 95 %, the buses have impressively demonstrated their suitability. As a next step in the right direction, the newly presented Citaro BlueTec Hybrid will be developed further into a Citaro G fuel cell hybrid. The infrastructure of the electric drive system can be retained, while the diesel engine and generator will be replaced by fuel cell stacks. Instead of tanks for diesel fuel and AdBlue, hydrogen tanks will be mounted on the vehicle roof.

The facts speak for the fuel cell as the drive system of the future. It will make the Zero Emission Vehicle a reality, with buses emitting no harmful exhaust gases, travelling extremely quietly and operating with a high efficiency. Hydrogen can be generated in a variety of ways. This drive system has demonstrated its efficiency and reliability in day-to-day operations.

World debut: Mercedes-Benz Atego BlueTec (7.5 t) with hybrid drive

Just as Daimler Buses leads the field in the hybrid bus segment, Daimler Trucks is the leader in the truck sector. No manufacturer offers a wider range, and no other manufacturer can boast as many vehicles in day-to-day customer operations. And the number is growing constantly: the Mercedes-Benz Atego BlueTec Hybrid is now celebrating its debut in Stuttgart, and will shortly be demonstrating its practical suitability during customer trials.

The Atego BlueTec Hybrid benefits from the worldwide Daimler Trucks network and a superb level of cooperation between the engineers in Stuttgart and Kawasaki, Japan, where around 200 light trucks have already been series-produced.

Daimler Trucks has generally opted for an architecture with a parallel hybrid.  This has proved most suitable for the technical powertrain configuration of the truck, and also offers advantages during procurement.  These costs are of lesser importanct to a city bus, owing to their generally higher price and the long period of first ownership. The goal is for the hybrid drive to recoup the first owner’s investment in all cases.

Downsizing saves weight for the benefit of payload

With a view to weight optimisation, downsizing is the order of the day for the Mer cedes-Benz Atego, which is in a payload-sensitive category with its permissible gross vehicle weight of 7.5 t. When it comes to hybrid drive, therefore, the engineers try to limit the extra weight of the second propulsion system while retaining the vehicle's performance by such measures as using smaller diesel engines. The compact, lightweight four-cylinder diesel engine with a displacement of 3.0 l develops an output of 92 kW (125 hp) and a maximum torque of 294 Nm. This is supplemented with a water-cooled electric motor generating a peak output of 35 kW and 200 Nm of torque. It is located between the clutch and the auto mated transmission. The electric motor mainly assists the diesel engine at lower and me dium engine speeds. Once the truck is cruising along after acceleration, it runs economically on diesel power alone, but electric power only is used when moving off.

The electric motor obtains its energy from lithium-ion batteries mounted in a housing on the left side of the frame. The battery pack weighs 87.5 kg and has a capacity of 1.9 kWh. The water cooler for the hybrid drive is mounted on the oppo site side. The batteries are charged by recuperated braking energy. The de velopers expect a fuel saving of up to 20% to be achieved during customer trials in the distribution sector.

World debut: Atego BlueTec Hybrid with 12 t gross vehicle weight

For high performance requirements, there is also an Atego twelve-tonner. This enters the scene with an identical architecture, i.e. parallel hybrid drive, but has different components adapted to suit the greater vehicle weight. In this case Daimler Trucks benefits from the cooperation with Eaton: the powertrain consists of the Mercedes-Benz OM 924 four-cylinder engine developing an output of 160 kW (218 hp) and 810 Nm of torque, plus the electric unit from the component manufacturer Eaton.

The electric motor generates a peak output of 44 kW and a maximum torque of 420 Nm. Power is transferred by an automated Mercedes-Benz G 85 transmission. In the Atego BlueTec Hybrid, both units working together produce a performance which can only be equalled by a truck with a powerful six-cylinder diesel engine. Thanks to the use of a lightweight four-cylinder engine, the Atego BlueTec Hybrid weighs only around 60 kg more despite the additional hybrid-drive components and the lithium-ion batteries.

The Atego BlueTec Hybrid with a gross vehicle weight of 12 t is likewise due to undergo rigorous day-to-day testing soon: in the coming year six units will be entering customer trials for a period of one year.

Canter Eco Hybrid: successful start-up in Japan

The greatest success so far for a hybrid-drive truck has been achieved by the Mit subishi Canter Eco Hybrid. Introduced in the summer of last year, around 200 units of this light truck have left the production lines to date. The Canter Eco Hybrid is the first light truck to have met the stringent exhaust emission standards in force in Japan since the summer, and also excels with a very favourable fuel consumption approx. 20% lower than that of a comparable diesel truck.

The drive system is based on a 3.0-litre four-cylinder diesel engine developing an output of 92 kW (125 hp) and a torque of 294 Nm – a very compact and lightweight power unit in relation to the overall weight. This engine also features exhaust gas recirculation and a particulate filter. It is combined with an electric motor which acts as a generator when braking (output 35 kW), as well as a lithium-ion battery pack with a capacity of 1.9 kWh. The batteries are charged by recuperated braking energy. To augment this effect the drive unit is disengaged during braking. Power is transferred by an automated manual transmission. A start-stop function switches the engine off when the vehicle is idling at standstill.

The Canter Eco Hybrid changes its operating mode depending on the driving situa tion. Electric drive is used when moving off. The diesel engine is switched on in addition when strong acceleration is required, and this powers the truck alone when cruising speed is reached. With a net weight of 2.9 t and a permissible gross vehicle weight of 4.5, 6.5 or 7.5 t, the Canter has a high payload despite its hybrid-drive system.

Canter Eco-D study: medium-heavy tipper with hybrid drive

The 2007 Tokyo Motor Show saw the presentation of the first concept study of a hybrid-drive tipper truck based on the Mitsubishi Fuso Canter. The outstanding feature of the Mitsubishi Fuso Canter Eco-D is the electrically powered tipper body. This considerably reduces noise and exhaust emissions, as the necessary power comes from the batteries and the diesel engine remains off while tipping is in pro gress. It would also be conceivable to drive other implements and attachments electrically, e.g. crane bodies or platform hoists. In the case of the actual pro pulsion system, the benefits of the Canter Eco Hybrid remain unchanged.

New: Canter Eco Hybrid entering its first customer trials in Europe

The Canter Eco Hybrid from the Daimler Trucks worldwide centre of competence for hybrid systems is such a convincing proposition that it is also making its way to Europe now. Before the end of this year, the first of 10 vehicles will be entering customer trials for a period of 3 years in Great Britain. This is a genuine first, for these are the first customer trials with hybrid trucks in Europe. In technical terms the powertrain is the same as on the Japanese Canter Eco Hybrid, however the vehicles are configured for European requirements and the engines for the European emissions standards.

Freightliner M2 Hybrid: electrically powered ancillary units

Freightliner, the largest truck manufacturer in North America and part of Daimler Trucks, is also developing hybrid vehicles using parallel systems like the other brands in the group. The latest, a medium cab-behind-engine truck in the M2 series with a permissible gross vehicle weight of 15 tonnes, is however configured expressly for North American conditions.

Here vehicles with platform hoists play an important role as service vehicles be cause overhead power lines are in widespread use. Accordingly Freightliner not only uses the elec tric drive unit as an alternative, and to assist the vehicle’s diesel engine, but also for emissions-free and quiet operation of the power take-off for a platform hoist, whose hydraulics are powered by a high-voltage battery. This advantage can be applied to numerous other applications, e.g. to drive tail-lift pumps for tankers or firefighting vehicles and many other equipment items. This approach also avoids unnecessary idling by the diesel engine.

The drive system of the M2 combines a compact 6.4-litre Mercedes-Benz OM 906 (US designation: MBE 906) six-cylinder in-line engine developing 186 kW/252 hp with an electric motor. This generates a peak output of 44 kW and a maximum torque of 420 Nm. Power is transferred by an automated six-speed transmission. Electric power is supplied by lithium-ion batteries with a total capacity of 5.5 Ah, which are charged by recuperation of braking energy. Fuel savings amount to around 25 to 30%.
The Freightliner M2 has successfully passed its practical trials, and celebrated its public debut in the summer of last year. The concept of this truck is so convincing that Freightliner now plans to produce a series of 1500 M2s with hybrid drive.

Freightliner Van: reliable and economical, entering series production

Courier services frequently make deliveries to businesses and households in parti­cularly emissions-sensitive locations, such as residential areas and pedestrian pre cincts. Frequently they are also on the roads at night. Among parcel services large numbers of these vehicles are in operation in North America. The Freightliner sub sidiary Freightliner Custom Chassis Corporation (FCCC) produces many thou sands of chassis for distribution vehicles each year. As what are called walk-in vans they are tailor-made for the typical requirements of American distribution opera tions, with a practical box body, a gross vehicle weight of 7.3 tonnes and a load capacity of 17.9 cubic metres.

For more than three years, 25 of these vans with hybrid drive have been success fully undergoing practical trials with a large fleet customer. During this period they have achieved outstanding results: large fuel savings and a high level of reliability amounting to an availability of 99%. A further 75 vehicles are being delivered as a result of this success.

The architecture of the van’s drive system follows the familiar parallel hybrid prin ciple, and is based on a 900-series (US designation: MBE 900) four-cylinder diesel engine with a displacement of 4.25 litres and an output of 125 kW (170 hp). The electric motor delivers 44 kW and is supplied with power by lithium-ion batteries.

Hybrid drive undergoing long-distance trials

Frequently changing acceleration and braking cycles, as well as a particularly emissions-sensitive operating environment, mean that hybrid drive is eminently suitable for short-radius transport. Depending on the topography, however, it can also produce noticeable fuel savings in long-distance operations. According to calculations by Daimler Trucks these amount to around 4% on average.
Owing to the high mileages covered, with a correspondingly high annual fuel consumption, the absolute advantages are potentially even greater than in the case of distribution vehicles in short-radius operations. This must be offset against a redu ced payload and limited installation space in semitrailer tractors or touring coaches. Daimler Trucks and Daimler Buses are also planning practical trials with hybrid-drive long-distance trucks and touring coaches in the future.

Excellent future prospects for hybrid drive

Specialists agree that hybrid drive has excellent future prospects. Clear advantages include highly reliable components, no additional maintenance requirements despite the additional powertrain components, environmental compatibility thanks to a considerably lower fuel consumption, quiet operation in electric mode and emissions-free driving over short distances. The favourable fuel consumption automatically leads to low CO2 emissions, and the emission of fine particulates is also significantly reduced.

The problem of electric energy storage, previously a great handicap of hybrid ve hicles, appears to have been solved. Modern lithium-ion batteries combine a high power density with a large storage capacity, and they are also able to cope with rapid charging/discharging cycles. They can also be expected to last for the entire operating life of the vehicle, though only extensive long-term tests can finally confirm this.

Emission measuring cycles are still lacking for hybrid vehicles

There are still problems that remain to be solved, however. Classification according to emission standards and the measuring cycle used to measure emissions are out­standing issues, for example. Rapid progress in these areas is essential to ensure that operators know where they stand. A standardised measuring cycle appears to be emerging in Japan, for example.

The considerable additional technology in a hybrid vehicle is naturally reflected in significantly higher procurement costs. In order to make hybrid vehicles a paying proposition for the first owner, and in order to increase the vehicle population rapid ly with a view to environmental protection, the question of public subsidies cannot be ignored.

There are examples of this in Japan and in the USA. In the latter case there are federal and state subsidies towards the extra cost of procuring buses with hybrid drive. In Japan the procurement of a Canter Eco Hybrid is already amortised after five to seven years, thanks to a subsidy towards part of the additional costs for the hybrid-drive system and the fuel savings during operation.

Copyright © 2007, Daimler AG