Development of Future NGV Engine Combining Benefits of Diesel and Petrol Engine

It is generally known that Natural Gas Vehicles (NGV´s) have considerable lower Well to Wheel (WTW) CO2 and Green House Gas (GHG) emissions than petrol vehicles. In the near future this argument solely will not be sufficient anymore as the European emission requirements for petrol and diesel vehicles will probably be approaching each other. However, Euro 4 emission requirements, which will become effective from 2005 on, are considerably different for spark ignited and diesel vehicles. To achieve comparable emission levels as NGV´s , NOx and particulate matter (PM) emissions of diesel vehicles should have to decrease with respectively a factor three for NOx and a factor ten for Pm. Forced by future emission requirements, diesel vehicles will have to make a significant step and the question that will be risen more often in the future is whether NGV´s can achieve the same or lower emissions than petrol vehicles and if the WTW CO2 and GHG emissions of diesel vehicles can be met. At this moment the WTW CO2 and GHG emissions of diesel and NGV´s are on a comparable level but can become less favourable for NGV´s in Europe since Natural Gas for the European market will in future be transported over longer distances from outside the EU and thus higher transport losses will occur.