Originally Posted by
contango
I find it hard to believe that a 60mpg diesel car from Europe can possibly produce more pollution than a 12mpg petrol muscle car from Detroit.
In is the NOx emissions that do in the diesel. Oddly, bio diesel produces higher NOx emissions than petrol diesel. However, this is not the problem it used to be with the introduction of low sulfur fuel in the USA the cat. converters can do a better job eliminating the NOx. Engine type makes a big difference, a two stroke moped puts out way more toxic fumes than even a Hummer, so MPG is only one factor in the total environmental equation.