A couple of announcements today from Honda and Mercedes-Benz have hailed the start of the inevitable arrival of diesel cars on U.S. roads nationwide. Mercedes said that it plans to offer Bluetec diesel-powered versions of the M-, R-, and GL-class SUVs in all 50 states starting in 2008. According to Mercedes, the cars will be the first diesel-powered vehicles to meet new EPA Tier II Bin 5 emissions ratings. (While Mercedes will put the Bluetec diesel-powered E320 in dealer showrooms next month, it is rated as only Bin 8 on the EPA emissions scale and so will be ineligible for sale in California and the four other U.S. states with equally stringent emissions standards.)
Meanwhile, Honda, which has been busy making headlines with its plans to bring hydrogen fuel-cell vehicles to market in 2008, has said that its new diesel engine also meets California emissions standards, which are the toughest in the land. Unlike the Bluetec engines, which inject a urea-based solution into the exhaust stream to clean up the emissions (a process dubbed AdBlue), the Honda engine employs a two-layer catalytic converter to convert nitrogen oxide into less environmentally harmful nitrogen, thereby making the car's emissions compliant with the EPA's Bin 5 requirement.
With DaimlerChrysler also poised to bring its next-generation diesels to the States in 2008, it looks like the trend towards diesel adoption that is already well underway in Europe, where half of all new cars are diesels, is beginning to catch on across the pond.