Nissan Diesel Motor Co. said Wednesday it will launch a 16-ton environmentally friendly truck in fall 2004.

The heavy truck will use a urea-dosing system to cut emissions of nitrogen oxide by about 50 percent, becoming the first vehicle to use the system in Japan. The system applies urea-containing water to emission gas to create chemical reactions that are useful in cutting nitrogen oxide, the firm said.

The vehicle also has a next-generation diesel engine that can cut soot emissions and improve fuel efficiency by more than 6 percent over current large diesel trucks, company officials said.

The truck maker is planning to build necessary refueling infrastructure for the vehicles by fall 2004 in cooperation with the government, gas station operators and related businesses, they said. The truck needs to refill a special tank with a mixture of urea and water to make the urea-dosing system work.

Nissan Diesel said the new truck can clear tougher exhaust regulations that take effect in 2005. Diesel vehicles will have to reduce soot emissions by more than 85 percent from the current level and nitrogen oxide emissions by more than 50 percent.