Potential of VVA systems for improvement of CO2, pollutant emission and performance of combustion engines

With Gasoline engines, a huge variety of variable valve actuation systems is already applied in series production, whereas with Diesel engines most activities still are concentrated on advanced development. The paper gives an overview on the respective potentials for fuel economy and emission improvements. With Gasoline engines, cam phaser will become the standard technology, both as stand alone solution but also in combination with other technologies like variable ch motion, variable valve titt, GDI and turbocharging long term, the cost effectiveness will determine the application of the different technical approaches. F With Diesel engines variable valve actuation C devices show much smaller potentials and consequently lower probabilty for a broad short term series introduction.