Ford Motor Co. has developed a new diesel-powered Ford Focus research vehicle that will meet California’s Ultra Low Emission Vehicle II (ULEV II) standards, which go into effect in 2007. The vehicle uses co-fueling of diesel and urea, an ammonia-based compound, to reduce nitrogen oxide (NOx) emissions to levels previously not achieved with diesel technology.The keys to the ULEV II Diesel Focus’ low emissions are a very efficient NOx reduction catalyst and a soot-trapping particulate filter. The catalyst uses the ammonia to remove NOx from the exhaust. The chemical urea, in a water solution, is a convenient way to provide ammonia and is automatically sprayed on to the catalyst as needed. The urea — stored on-board in a small bottle like windshield washer fluid — is odorless and non-flammable.To ensure that the urea container is always filled, two tubes on a specially designed fuel nozzle fit to matching tubes in the fill pipe. This is called “co-fueling.” Co-fueling fills two separate tanks at the same time, so the driver does not need to make a second stop to replace the additive. Co-fueling is seamless for the customer.“Co-fueling with urea in a common-rail diesel engine allows us to produce a vehicle that provides the performance and fueling process customers are accustomed to,” said Dick Baker, corporate technical specialist for Ford’s Advanced Diesel Systems group. He added that Ford is working with other companies to develop an infrastructure for co-fueling.Along with the NOx catalyst, a particulate filter is used in the ULEV II Diesel Focus to trap carbon particles. Particulate filter technology is being developed by all diesel manufacturers to reach the future emission requirements, and to provide customers with a diesel vehicle that has no smoke and no odor. Availability of low-sulfur diesel fuel will help reduce the need for the particulate filter.“This prototype vehicle is a great example of what could be done in the future to make diesels fully comparable to gasoline vehicles in emission control, with lower CO2 emissions and excellent fuel economy,” says Baker.