Re: "DCX: Diesel meets EPA's '07 rules" (Aug. 11): It's certainly good news that DaimlerChrysler has built a diesel engine that can meet the EPA's upcoming emission standards for 2007. But the key question facing the auto industry in its drive to develop new diesel-powered cars is not whether they can make them "clean."
As you noted, Toyota and Volkswagen have also demonstrated that they can build diesel engines that can meet future environmental targets. The key question is whether automakers will use the greater efficiency of the clean diesels to improve fleetwide fuel economy and reduce U.S. reliance on imported oil.
During the last 20 years, automakers have designed car engines to work more efficiently. But greater engine efficiency has not translated into reduced energy consumption.
Instead, automakers have focused on greater horsepower, faster acceleration and heavier vehicles. As a result, fleetwide fuel economy is at its lowest point in more than two decades.
If automakers produce a truly clean diesel engine that dramatically increases fuel economy across their entire fleets, it will improve public health, air quality and U.S. energy security.
But if the result is merely bigger, heavier and more powerful SUVs that do nothing to break our addiction to imported oil, we will have missed a historic opportunity.