text: congestion droped around 60 percent in the capital of france after five continuos days of intesifying smog. The smog debated between beijing france and china which is the most polluted city. people wanted to know what was to blame for this. The people blamed diesel since frnace has created a tax policy that is in favor of the use of diesel or the use of gasoline. Abgout more than half of frances vehicles are fueled by diesel. 53.3 percent average of vehicles are diesel engines in the rest of europe.