Abstract
Keywords Spark ignition engine, port deactivation, charge dilution, fuel consumption, small displacement
Abstract Technologies for fuel consumption reduction are only effective when the customers are willing to purchase them. Especially with regard to the market segment of sub-compact cars, the customer is only accepting such technologies that show a reasonable cost-to-benefit ratio.
Port deactivation is a very cost efficient possibility to increase the dilution tolerance for exhaust gas of four-valve engines without compromising the full load performance. The fuel consumption of a sub-compact class vehicle in the European drive cycle can be reduced by 3 to 6 per cent. The proven port fuel injection and the three-way-catalytic converter can be retained.
80 per cent of the fuel consumption reduction of gasoline direct injection operated in stratified charge mode can be achieved with gasoline engines below 1.6 litre displacement while the additional product cost are less than 20 per cent.
Fiat-GM Powertrain is therefore consequently developing port-deactivation for the further refinements of their small gasoline engines.
The following paper describes the optimisation of port deactivation systems and compares the technology to the other thermodynamic measure.
The solutions applied to the different engine product lines of FIAT-GM Powertrain with displacements below 1.6 litres are described.