text: If you have a truck in America, what do you think your gas is doing to the envirnment? Wll, in France they use diesel fuel instead of gasoline, which means 67% of their vehicles is diesel. Car traffic in France was 60%, after five days of intensifying smog, and where do you think that smog came from? Deisel! cold nights and warm days caused the warmer layer of air to trap car emissioms. Paris typicaly has more smog than other European capitals, last week Paris had 147 micrograms of particulate matter per cubic meter compared with 114 in Brussels and 79.7 in London.