Search Results

In this paper the relationship between weight reduction and fuel economy is determined. This is executed with simulations for the three different propulsion systems ICE (internal combustion engine), hybrid system and fuel cell (FC) system. Furthermore, the three different vehicles classes compact, mid-size and SUV are considered along with two driving cycles, NEDC and HYZEM. The re-sizing of the propulsion systems according to the lighter vehicle weight to achieve the same acceleration as the basis vehicle is implemented as well. As an overall result it is established that no general value for the fuel consumption reduction per weight reduction exists. It is very important to consider all boundary conditions, especially the used driving cycle, the examined vehicle class, the type of propulsion system and a possible powertrain re-sizing. In detail the results show values between 2 and 8 % fuel consumption reduction at a 10 % weight reduction.

Starting with NECAR 1 in 1994 DaimlerChrysler has developed a series of fuel cell (FC) concept vehicles to prove the practicability of FC technology in mobile applications. Within the next two years the first buses (2003) and passenger cars (2004) will be given into customer hands indicating the start of a new phase within FC technology development. Among DaimlerChrysler's concept vehicles, Necar 3 and Necar 5 are using methanol as fuel. Methanol is an interesting option, because its storing is much easier than the storage of pure hydrogen. In a rather simple process and at low temperature it can be reformed into a hydrogen rich gas. This paper is dealing with the simulation and the design of methanol FC powertrains with Matlab/Simulink®. The results are fuel consumption with special regard to the operating strategy and the dimensioning of the FC powertrain's components.