The paramount goals for Mercedes-Benz in vehicle development are maximum ride comfort, dynamics and safety combined with economical consumption and environmentally-compatible emission levels. “For the drive concepts of the near future the objective is to make petrol cars as efficient as diesels, and diesels as clean as petrol cars” stated Dr. Thomas Weber, Member of the Board of Management of DaimlerChrysler AG responsible for research and technology and for development at the Mercedes Car Group.
For the petrol engine car, the main emphasis is on reducing fuel consumption even further. With the second-generation spray-guided petrol direct injection system, the engineers at Mercedes-Benz have achieved a crucial innovation that allows considerable fuel savings. Using the current 3.5-litre V6 as the basis, this technology was implemented under the bonnet of the new S-Class. This vehicle, which incorporates a compact, high-torque electric motor, will be presented in Frankfurt as the “DIRECT HYBRID.”
Now that the particulate filter has been introduced as standard equipment, the task for the diesel is to adhere to the most stringent exhaust limits worldwide with regard to nitrogen oxide emissions, too - while retaining the celebrated fuel economy. Nitrogen oxides are currently the only exhaust gas component still emitted in greater quantities by the diesel than by the petrol engine. The goal of achieving the lowest possible emissions has been implemented commendably by the “BLUETEC HYBRID” concept car based on the new 3-litre V6 diesel in the new S-Class — and also incorporating a high-torque electric motor. The crucial element in the success of this system is “BLUETEC,” a new exhaust gas purification technology that reduces the nitrogen oxides by about 80 per cent through selective catalytic reduction (SCR). This technology makes the “BLUETEC HYBRID” the cleanest diesel in the world.
Both of the drive systems in the concept cars introduced in Frankfurt are combined with an electric motor integrated in the drive train, thereby becoming what are called “mild hybrids”. This makes it possible to once more significantly reduce the already excellent fuel consumption of the optimised combustion engine, especially in urban stop-and-go traffic. The combustion engine switches off whenever it is not needed. At other times, the combination of combustion engine and high-torque electric motor act in concert to ensure a powerful and silky-smooth start when pulling away. Moreover, the electric motor reclaims energy during coasting and braking. These combined features allow a 20 per cent reduction in fuel consumption in the “BLUETEC HYBRID” relative to the comparable predecessor model, and as much as a 25 per cent reduction in the “DIRECT HYBRID.”
The two drive systems not only provide a dynamic driving performance, but also are extremely fuel-efficient and comply with the most stringent emissions standards worldwide. The drive system of the vision S320 BLUETEC HYBRID have a combined output of 179 kW/243 hp and 575 Nm of combined torque. The car can accelerate from zero to 100 km/h in 7.2 seconds and its top speed is electronically limited to 250 km/h. The vehicle is extremely fuel efficient, consuming only 7.7 litres of fuel per 100 km in the NEDC. The corresponding values for the S 350 DIRECT HYBRID are: 221 kW/300 hp; 395 Nm, 7.5 seconds, 250 km/h and 8.3 litres/100 km.
In the coming years, the hybrid - either in its mild or full hybrid configuration - can supplement the combustion engine in certain regions and traffic situations where it represents a reasonable and economical option for increasing dynamics, comfort and fuel efficiency. Trend-setting examples of such hybrids are the “DIRECT HYBRID” and “BLUETEC HYBRID” concept cars introduced at the IAA.
On 22 August 2005, DaimlerChrysler and General Motors (GM) signed a cooperation agreement regarding the joint development of hybrid drive systems begun in late 2004. In a memorandum of understanding, another partner, BMW, has now declared its intention to conclude an agreement with GM and DaimlerChrysler towards the end of the year. The three global automakers are cooperating in order to pool their expertise for the rapid and efficient development of future hybrid drive systems.
Mercedes-Benz is combining its clear commitment to the combustion engine as the indispensable basis for the coming years with a strong effort to help establish clean fuels and fuel alternatives. Their use goes a long way towards reducing emissions, because they immediately make all vehicles in the market cleaner and not only new cars. Synthetically produced designer fuels from natural gas or biomass are one option here. In particular, the fuels produced from biomass can contribute towards reducing CO2 emissions. In the ideal case, the CO2 produced by the combustion of biogenic fuels was previously absorbed by the plants during their growth, resulting in a closed CO2 cycle. Mercedes-Benz is actively participating in making SunDiesel a viable product for the market.
Yet the fuel cell remains the vision of researchers and developers at Mercedes-Benz for the automotive drive of the future. They have been working on it for more than ten years. The company has more than 100 fuel cell vehicles, from passenger cars to buses, engaged in road trials throughout the world — the largest fleet of its kind. To date, the A-Class F-Cell fleet has covered a total of around 440,000 kilometres in around 90,000 hours of operation. The reactions of the customers and passengers are very positive and give valuable insights that will help ensure the success of further development work.
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