Volkswagen has developed a new Adblue system which will cut diesel NOx emissions by “around 80%” compared to current engines.
The technology is already used in the Passat 2.0 TDI Evo with 150PS, and the manufacturer will gradually introduce it to all models with 2.0 TDI Evo engines, including the next generation Golf which will soon see its world premiere.
The system involves a ‘twin dosing’ process where Adblue is injected selectively upstream of two SCR (selective catalytic reduction) catalytic converters.
The twin dosing process is designed to compensate for a system-based disadvantage of diesel engines.
Modern diesel engines emit less CO2 than petrol engines because diesel fuel has a higher energy density and the combustion process is more efficient.
Diesel engines are also subject to special requirements, however, since fuel combustion takes place with excess air.
The main constituent of air is nitrogen and this reacts with oxygen during combustion, thereby forming nitrogen oxides.