Lest you think Honda's devoting all its attention these days to developing future instruments of destruction, you can take some comfort in the fact that it is (for now) primarily a car company and, as such, is still working on technology to help us humans while we're stuck driving ourselves around. To that end, the company's just unveiled a new diesel powertrain system that is says will run as clean as a gasoline-powered car, not to mention provide better mileage. Diesel-powered vehicles are already known as gas-sippers, of course, but also have higher exhaust levels of nitrogen oxide. To cut that down, Honda incorporated a rather dangerous-sounding two-layer catalytic converter into the drivetrain, which converts the nitrogen oxide into less environmentally-harmful nitrogen. The first cars using the new diesel technology are set to hit the U.S. market in 2009, with Honda also open to the idea of licensing the technology to other automakers. In related news, Honda also announced an updated version of its Honda FCX fuel-cell vehicle, upping the maximum driving range to 354 miles and the max speed to a respectable 100 miles per hour. It'll be available in limited numbers in Japan and the United States in 2008, and we assume that when they say "limited" they really mean it.