http://www.dw.de
Trucks are the workhorses of trade - both national and international. They're also notorious air polluters. On the highway, they regularly block traffic and belch out clouds of acrid smoke, rich in harmful emissions and CO2. But there have been some changes in recent years.
For more go to: http://www.dw.de/drive-it-the-motor-magazine-2012-10-17/e-16264462-9798