The Dirty Truth About 'Clean Diesel'

A New York Times opinion piece explains the problems with diesel fuel.

The diesel engine is inherently efficient: Even a heavy sedan can get as much as 50 miles per gallon, while producing fewer carbon dioxide emissions per mile. The relatively light carbon footprint of Diesel’s invention meant that in the late 1990s, policy makers in Europe, eager to meet Kyoto Protocol goals, initiated a “dash for diesel.” Consumers got a push from sharply reduced taxes on diesel fuel.

Industry soon took the hint: Diesel could be marketed as green. The Diesel Technology Forum’s website proclaims that “Today’s ultralow sulfur diesel, advanced engines and effective emissions control combine to achieve near zero emissions.”

Diesel exhaust is laden with insidious soot particles, the so-called PM 2.5 (particulate matter smaller than 2.5 microns, or one-thirtieth the width of a human hair), which allow carcinogens to penetrate deep into tissues and organs. In other words, a driver who steps on the accelerator of a diesel car may be filling the lungs of nearby pedestrians, cyclists, infants in strollers and other drivers with potentially deadly particulate matter.