On the Road to Emission-Free Mobility: Mercedes-Benz - Engine for Sustainable Mobility Today, Tomorrow and the Day After

Since then, Mercedes-Benz has been consistently pursuing the route to emission-free mobility. All relevant technologies – from CDI and BLUETEC, through petrol direct injection (CGI) and hybridisation to battery and fuel cell drive – have been further developed and, in some cases, have already been in series production for years. In contrast to other premium manufacturers, Mercedes-Benz has the advantage of being able to use synergies from within the Daimler Group. One example of technology transfer between the commercial vehicle and passenger car divisions is the multiple award-winning BLUETEC exhaust gas treatment system. Presented at the IAA for commercial vehicles in 2004, the BlueTec exhaust treatment system for diesel engines made its debut in January 2005 in the Actros heavy truck, enabling it to fulfil the Euro 4 and Euro 5 exhaust gas standards ahead of time. May of the same year saw the launch of the first Citaro city buses with BlueTec. In 2006, the technology for the world’s cleanest diesel engines made its first appearance in a Mercedes-Benz passenger car – the E 320 BlueTEC – which was promptly voted “World Green Car of the Year 2007”.

Diesels as clean as petrol engines, petrol engines as fuel-efficient as diesels
More Mercedes-Benz BlueTEC passenger cars are set to follow this year. The GL, M and R-Class BlueTEC SUVs, which were already successfully introduced in the U.S. in 2008, will also come to the European market in autumn – along with the new E 350 BlueTEC. All new BlueTEC models already fulfil the limits laid down in the EU-6 standard scheduled for 2014. Also in 2006, and in parallel to the optimisation of the diesel engine, Mercedes-Benz was the first vehicle maker to introduce extremely fuel-efficient piezo petrol direct injection with jet-guided combustion – in the CLS 350 CGI. This technology represents a milestone in fuel efficiency and also brings considerable reductions in emissions. Mercedes-Benz has since introduced petrol direct injection into 4 and 6-cylinder engine versions of the C and E-Class. Progress is particularly evident in the newly introduced four-cylinder direct injection petrol engines in the latest E-Class. Despite their significantly smaller displacements, they generate more power than the preceding six-cylinder engines, yet consume up to 21 percent less fuel. This technology is being introduced successively across all petrol engines. Highly efficient CGI engines are now also available in the C-Class. The results speak for themselves – the new C 250 CGI boasts a fuel consumption of only 7.2 litres, at a power output of 150 kW/240 hp. Diesel versions start with fuel consumption as low as 4.8 litres per 100 kilometres. With a peak power output of 125 kW/170 hp and a maximum torque of 400 Nm, the most frugal C-Class of all time sets a new benchmark in fuel efficiency. The objective of making petrol engines as fuel-efficient as diesels and diesels as clean as petrol engines, has already been achieved in many Mercedes-Benz models. The account balance of BlueEFFICIENCY models currently stands at – twelve models with a CO2 value below 140 grams per kilometre, 24 vehicles emit less than 160 grams per kilometre and a total of 36 models come in beneath 180 grams per kilometre. The new, extremely frugal CGI engines and the highly efficient BlueTEC exhaust gas treatment system contribute considerably to this result. In particular, the technology for the world’s cleanest diesels has laid the foundation for the future of economical, high-torque diesel engines in the U.S. Right now, state-of-the-art diesel technology is delivering its best fuel-consumption figures in large saloon cars and non-hybrid SUVs in particular. This is evidenced by the success of the E 320 BlueTEC, with which Mercedes-Benz kicked off the renaissance of diesel power for passenger cars on the U.S. market in October 2006.

Further efficiency improvements through needs-based hybridisation
The main key to greater efficiency and environmental compatibility lies in driveline electrification – not only in electric cars, but also in vehicles with combustion engines. The potential is considerable – it ranges from ancillary units, through the start-stop function all the way to hybridisation. To this end, Mercedes-Benz has developed a modular hybrid platform that offers a vast range of expansion possibilities in terms of performance and field of application. Hybrid modules with various levels of power output and batteries with the right degree of capacity can be combined with the highest volume Mercedes-Benz petrol and diesel engines. All hybrid modules are – like the high-volume four and six-cylinder combustion engines – compatible with the 7G-TRONIC automatic transmission. From this basis, all variations of hybrid drive can be realised – from mild hybrid all the way to full hybrid, which can also drive on electric power alone. One further option is the plug-in hybrid, whereby the battery can also be charged from an electrical outlet in order to extend its range. Mercedes-Benz is setting benchmarks with the broad range of this modular platform – from technology, through economy to safety and driving comfort.

S 400 HYBIRD – the most fuel-efficient luxury saloon with a petrol engine
This is the position occupied by the S 400 HYBRID, with which Mercedes-Benz was the first European manufacturer to offer a hybrid passenger car. The combination of the modified V6 petrol engine and the compact hybrid module makes the S 400 HYBRID the world’s most fuel-efficient luxury saloon with a petrol engine (7.9 l/100 km, NEDC combined). At 186 grams per kilometre, it also boasts the world’s lowest CO2 emissions in this vehicle and performance class. Furthermore, the S 400 HYBRID is the first series production hybrid with state-of-the-art lithium-ion battery technology. The modular hybrid concept from Mercedes-Benz enables the application of petrol and diesel engines of various configurations, as demonstrated by the Vision E 300 BlueTEC HYBRID. Mercedes-Benz experts believe that clean diesel hybrids currently offer the greatest potential for fuel savings in the upper vehicle segments. Equipped with the new four-cylinder diesel, the Vision E 300 BlueTEC HYBRID underscores this position with its low combined consumption of around 4.5 l/100 km (preliminary figure). This equates to CO2 emissions of only 119 grams per kilometre. At the same time, the diesel hybrid generates a refined level of performance that, at 165 kW/224 hp and between 580 and 600 Nm of torque (both combined), is above that of current six-cylinder diesels.

“An S-Class with less than four litres consumption is do-able”
This is the positive answer to the fundamental question surrounding the future of large cars. Dr. Thomas Weber comments, “Comfortable, refined and safe premium cars such as the E-Class and the S-Class are among our core competences and a major factor in our business model. That will remain the case in future, too. Adopting the formula of ‘BlueEFFICIENCY package plus hybrid platform’, even an S-Class with less than four litres fuel consumption is conceivable - specifically through the combination of a plug-in hybrid drive with targeted vehicle optimisation, particularly in the fields of aerodynamics, lightweight design and energy management.” Mercedes-Benz has at its disposal all the necessary conceptual and technological means for the systematic electrification of vehicles. This means that diesel and petrol engines – combined with efficient transmissions - will remain, as they have been for many decades, the backbone of road-going mobility around the globe.

The combustion engine is irreplaceable for the foreseeable future
The application of state-of-the-art internal combustion engines with and without hybridisation is an indispensable option for the future. In the first instance, they are needed if only because electric drivelines cannot be produced in the required numbers and at the costs necessary for the high-volume segment in the short term. Therefore, the quality of combustion engines will also be a decisive factor in determining how much fuel can actually be saved and the degree to which emissions can be avoided. One thing is clear – all advances being made mean electric vehicles will not be able to replace vehicles with combustion engines in the short term. Modern diesel and petrol engines will also remain the driving force for the automobile in the longer term – in individual mobility with passenger cars, over long distances in particular, and especially in the transportation of goods with heavy trucks. As a consequence, Daimler and Mercedes-Benz engineers have developed a broad-based approach, in which the internal combustion engine continues to play an important role that is far from being that of an obsolescent model. The outcome is a multi-faceted driveline mix – dependent on vehicle class, usage profile and customer preference, Mercedes-Benz is bringing to bear a range of different vehicle concepts with tailor-made drive solutions. In long-distance travel, the dominant force will continue to be modern combustion engines with and without hybrid modules, complemented by fuel cell vehicles. This scenario can be boosted by plug-in hybrids and fuel cell cars for cross-country traffic. In city traffic – primarily in the increasing number of mega cities around the globe – the roads will be characterised largely by local emission-free vehicle concepts with battery and fuel cell drives.

Comprehensive commitment to alternative fuels and infrastructure
This broad-based and determined commitment also encompasses – over and above the further development of driveline technology – the testing of alternative fuels and the development of a suitable infrastructure, in respect of facilities such as battery charging points and hydrogen fuel stations. Examples of this work can be seen in projects such as “e-mobility” Berlin or the fuel cell project in Hamburg. For the project in Berlin, Daimler is providing more than 100 electric vehicles from the Mercedes-Benz and smart brands. Project partner RWE is managing the construction of 500 electricity charging stations throughout the city. For the Hamburg project, Mercedes-Benz is supplying the city with ten fuel cell buses and 20 B-Class F-CELL vehicles, while Vattenfall sources the necessary hydrogen from regenerative energies and partners Total and Shell build a total of four hydrogen fuel stations in Hamburg. For tomorrow and the day after – cars with electric drive In parallel to the optimisation of vehicles with combustion engines, Daimler and Mercedes-Benz engineers are working intensively towards the company’s stated long-term goal – local emission-free driving with fuel cell and battery-powered vehicles. Mercedes-Benz and smart electric test vehicles have already proven themselves in far-reaching field trials, clocking up several million emission-free test kilometres under everyday driving conditions. The latest generation, equipped with close-to-production technology, is currently being tested within the scope of ongoing pilot projects.

The electric car – one of several options
In respect of the minimisation of CO2 emissions in road traffic, the electric car is currently being presented as the “favourite”. This has led to the impression among the general public that the age of the electric car is right around the corner. It is fair to say that, whether they run on fuel cells, battery power or range extenders, electric cars offer enormous potential when it comes to environmental friendliness. They are, however, not yet ready for series production. Alongside insufficient production capacity for powerful and safe batteries, there is also no comprehensive infrastructure of charging facilities or of hydrogen fuel stations for fuel cell vehicles. Local emission-free, quiet and highly efficient driving is, in the first instance, most suited to major urban areas, where access restrictions and environment zones are now commonplace. A critical pre-requisite for all electric drive systems is a powerful, safe and reliable energy storage device. The performance of the overall electric system is dependent upon the battery, starting with its storage capacity. For this reason, Daimler is focusing its attention on the development of a powerful traction battery. Alongside the aforementioned characteristics, it must also have a long lifespan and a high level of crash safety and be suitable for recycling. All these pre-requisites are offered by the new lithium-ion battery, which has already proven itself in hybrid applications. Its particular benefits lie in its compact dimensions combined with a considerably higher capacity compared with existing nickel metal-hydride batteries. Furthermore, thanks to the innovative cooling system and temperature management, it also possesses a high degree of reliability independent of climatic conditions and outstanding cold-start characteristics.

Targeted commitment to electric mobility infrastructure
In order that the electric car can become a real option for the security of sustainable mobility, a number of technological limitations must first be overcome. In particular, the thus-far relatively low range of batteries and their lengthy charging times are in conflict with what people have come to understand over a period of decades as “auto-mobility” and what they continue to expect – freedom, the ability to drive anywhere at any time, and to be able to refuel in virtually every part of the world. Daimler and Mercedes-Benz are thus committed to the development of the necessary infrastructure within the scope of programs such as “e-mobility Berlin”. Further challenges still to overcome include the costs, technical every day usability and, not least, the issue of regenerative primary energy. Mercedes-Benz has already developed suitable vehicle concepts. The close-to-production Concept BlueZERO provides a tangible perspective on environmentally compatible electric mobility. The intelligent, modular concept uses a single vehicle architecture to facilitate three models with different driveline configurations capable of fulfilling all customer demands for sustainable mobility. These are the BlueZERO E-CELL with battery-powered drive and an electric-only range of up to 200 kilometres; the BlueZERO F-CELL with a fuel cell that achieves an electrical range of considerably more than 400 kilometres; and the BlueZERO E-CELL PLUS with electric drive and an additional combustion engine as a range extender. This version boasts an overall range of up to 600 kilometres and can drive on electricity alone for up to 100 kilometres – it is also completely suitable for everyday use in respect of safety and packaging. At the very core of electric mobility is the battery. State-of-the-art, high-capacity lithium-ion batteries are at the heart of vehicle electrification in all areas. This is why Daimler is working on the industrialisation and standardisation of this battery technology, thus establishing the pre-requisites for the achievement of reasonable margins and enabling products to be offered at fair market prices. The development objective is the standardised, industrialised production of lithium-ion batteries for hybrid vehicles, as well as for fuel-cell and battery-powered vehicles.

In the field of lithium-ion technology, Daimler benefits from its in-house expertise gathered over many years of research work. The company has already filed more than 600 patent applications in respect of battery-powered vehicles over the last 30 years – more than 230 of which are in the field of lithium-ion technology. In order to secure its pioneering role in this sector over the long term, Daimler took a 49.9 percent shareholding in Evonik subsidiary Li-Tec in 2008. In addition, the joint venture “Deutsche Accumotive GmbH & Co. KG” (shares: 90% Daimler, 10% Evonik) was also founded. This means that, as of 2012, Daimler has exclusive access to production capacity for state-of-the-art lithium-ion batteries that can then be manufactured to suit the specific requirements of all individual automotive applications – ranging from hybrid to electric vehicles, and from passenger to commercial vehicles. Thus, Daimler has direct access to the key technology for emission-free driving. In parallel, Daimler is also pushing forward the development of electric drives, where it makes sense to do so, together with other partner.

Sustainable mobility through a needs-based drive mix
“The mobility of tomorrow will not be borne by one solitary solution, but instead, the load will, quite literally, be spread across several shoulders,” comments Dr. Thomas Weber. “The key to forward-looking, i.e. environmentally compatible and, at the same time, needs-based auto-mobility, is a multi-faceted drive mix comprising combustion engines, hybrids, battery power and fuel cell drives. These drive technologies, that we are systematically bringing to market to the benefit of our customers and the environment, are an integral part of our strategy for sustainable mobility.”