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This paper deals with development and optimization of combustion process, cold start system and exhaust after-treatment carried out on the steady state and transient test bed as well as with vehicle development on chassis dynamometer and on the road at standard ambient temperatures and under cold conditions of a) SPFI or MPFI-SI engine with catalyst (closed loop), neat ethanol fuelled, compared to b) glow plug assisted direct injection methanol engine equipped with oxidation catalyst. The main emphasis is laid on the optimization of the cold start behaviour with and w/o catalyst in order to obtain low emissions, primarily during the first phase of the FTP 75 cycle. The emission results show that with both engine types the achievement of US-1994 limits will be possible, including a very low aldehyde emission.

During the last four years FIAT AUTO has cooperated with AVL in the development of three generations of ethanol vehicles for the Brasilian market for current, 1992 and 1997 Brasilian emission standards. This paper deals with suitability of ethanol as SI-engine fuel combustion system development and calibration strategies for 1992 lean burn engines and 1997 TWC-concepts transient and warm up development single fuel cold start systems TWC emission control requirements vehicle performance, fuel economy, emissions with and w/o catalyst. The paper shows that the concepts chosen allow calibrations with sufficient margin with respect to emission standards. Cold start and driveability can be developed for single fuel operation down to 0 deg. C. Vehicle driveability and performance are on a competitive level. For aldehyde control the TWC is a very good solution. Application problems with TWC can occur if the catalyst is located remote from the engine.