Clean, Green, Diesels -- Will they find an American Market?

Gasoline carbon content per gallon: 2,421 grams

Diesel carbon content per gallon: 2,778 grams

Clean Diesel as the “green alternative”

When I was in Germany earlier this year I rented two clean Diesel automobiles. In fact, it seemed that in the moderate car rental price range the only cars I could rent were Diesel-powered vehicles. In Germany about 40% of autos sold are diesels, and they get 30%+ more miles per gallon. I drove an Audi A4 Diesel over 1000 km, and found it to be a comfortable and economical vehicle. Since these German cars are turbo-charged, performance was more than adequate. Although once I got the car over 200 km/hr on the autobahn, it felt like I was leaving the envelope of safety and total control. Noise, always an issue with the Diesels that previously came to the U.S. (mostly M-B or VW), was only noticeable at idle. Once the car got going, it was as quiet as any ICE-powered car.

The other factor that was different in Germany than currently in the U.S. was the price differential for Diesel fuel, as in Germany Diesel was less than regular gasoline, whereas in the U.S. due to environmental measures, the cost comparison is the other way around. The drop in sulfur content in refined Diesel had upped the price of the fuel, but made it far more environmentally friendly. However, NOX emissions remain an engineering problem, one that M-B solved with their urea injection system. Honda, however, has accomplished this just a effectively with an elegant system of their own.

The second Diesel that I rented, a VW Golf, was not as positive experience, as I was involved in a crash with it that my have been partially attributed to a lack of punch (and of course my driver judgment). Diesels are simply not that quick from standing start, and I wonder if American drivers will accept these cars because of this. The fact that electrics have such high torque and are so fast from standing start may make them the long-term favorite in the American market. We are a 0-60 nation of drivers.

Another shortcoming of the older Diesels was their difficulties in starting in cold temperatures. European climates are more moderate that that of the most northerly states. However, since the migration of some many Americans to the Sun Belt, I doubt that will be a major issue in marketing these cars. Additionally, Americans still have the memory of Diesel buses and large trucks with their dirty exhaust fumes, and so the German car makers are going to have to overcome a historical legacy. We all remember getting behind a dirty bus.

There is no doubt that since the first auto Diesel was marketed by M-B in 1935 – and especially the importation M-B and VW Diesels beginning in the late 1960s, that there were great advantages to these cars. Above all, they are incredibly rugged engines, and are durable well beyond a comparable ICE. They are relatively simple. But because of the need for thicker cylinder walls, and expensive injection pump mechanisms, they are also more expensive to make.

Finally, for some Americans green means getting away from any fuel combustion system. Even though electricity is a product of fossil fuel burning, electric cars are one step beyond the sight of a consumer. If the pollution is out of sight, perhaps it is also out of mind.