Natural Gas - an environmentally friendly fuel for urban vehicles: the SMART demonstrator approach

The main objective of this project was to confirm the high potential of Natural Gas as fuel for downsizing turbocharged engines. For this purpose, a demonstrator vehicle has been developed when modifying a Smart gasoline vehicle. The target was to achieve low CO₂ emissions with a maximum level of 100 g/km on a European Driving Cycle (NEDC), while keeping pollutant emissions below the EURO IV level. At full load conditions, thermal efficiency is 25% higher than for gasoline. That represents a CO2 gain of 35%.

After a brief description of the main Natural Gas characteristics as a transportation fuel, the downsizing approach will be described as a most promising way to reduce engine specific fuel consumption. Results obtained on bench and with the Natural Gas Smart vehicle will be presented focusing the CO₂, regulated emissions, drive-ability and driving range in accordance with “urban” expectations.