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From SAE-Papers and several publications, the easy, effective function and management of an EHC-System is well known. The direction of the development is now to reduce the electrical energy consumption and to show the mechanical durability of the heating structure. This paper shows that it is possible to minimize the energy consumption and that the required service life can be in principle achieved with the introduction of these developments. The physical characteristics such as mass, geometrical surface area, cell density and electrical resistance of the EHC construction could be optimized to save energy. This, in conjunction with the operating parameters of the engine, the controlling of the secondary air and the catalyst configuration, will enable the goals to be met. The design of the converter, the physical characteristics and the results of the tests are shown with the Porsche 944 S2 and 968 applications.

Metallic substrates for catalysts constitute a supporting technology to meet the various emission legislations world wide for passenger cars as well as for 2- and 3-wheelers. Hot tubes offer additional advantages, especially for 2- and 3-wheelers in combination with metallic substrates or as independent systems. Low thermal capacity data indicates an early light off. High thermal conductivity assists the catalyst under engine misfiring conditions. The wall thickness of the foil material used is responsible for low back pressure and high engine performance. The greater geometrical surface area of metallic substrates and hot tubes in combination with structured surfaces offers the automotive industry an opportunity to reduce catalyst volume. Simple, economical canning methods are a field of special interest in the automotive industry. These advantages combined allow metallic substrates a significant market share in automotive applications.