Future Policy for Motor Vehicle Exhaust Emission Reduction(second report) - Chapter 5

Exhaust Emission Reduction Measures for Off-road Vehicles

(1) Introduction of exhaust emission regulations for off-road vehicles and its applicable motor vehicles

With regard to those off-road vehicles currently not subjected to motor vehicle exhaust emission regulations, they emit a considerable quantity of nitrogen oxides and particulate matters. Because of this reason, it is appropriate to make them subjected to the motor vehicle exhaust emission regulations. In this case, taking into consideration the emission contribution ratio, and so forth, among off-road vehicles fueled by diesel oil (hereinafter referred to as "diesel off-road vehicles"), it would be proper to make motor vehicles mounted with engines with a rated output of 19 kW or more, but of less than 560 kW subjected to the said regulations. As regards the introduction of the regulations to other off-road vehicles, it is advisable to conduct continual studies, while evaluating the trend of emission contribution ratio, the development situation of exhaust emission reduction technologies, and so on.

As for exhaust emission components to be reduced, it is recommended that nitrogen oxides, hydrocarbons, carbon monoxide and particulate matters be controlled. As for black smoke among particulate matters, it would be proper to continue studying along with the smoke tests.

(2) Exhaust emission test procedure

When enforcing the exhaust emission reduction measures for the diesel off-road vehicles mounted with engines with a rated output of 19 kW or more, but of less than 560 kW, it is advisable to adopt the measuring mode as posted in Attached Table 4, in which the engine is measured as a unit.

(3) Target values for permissible limits and achievement time

With regard to nitrogen oxides, hydrocarbons, carbon monoxide and particulate matters emitted from the diesel off-road vehicles mounted with engines with a rated output of 19 kW or more, but of less than 560 kW, it would be proper that these are reduced according to the target values for permissible limits as indicated in Attached Table 5.

In this case, it is imperative to carry out efficiently the design, development, preparation of production, and so on of the engines and bodies for the diesel off-road vehicles in addition to preparing the exhaust emission measuring equipment and facilities, so that the target values may be achieved by the year 2004.

(4) Others

With a view to assuring proper functioning of the exhaust emission control devices for off-road vehicles in use, it is necessary for engine manufacturers to perform the technical development and measures concerning the assurance of durability. Moreover, it is indispensable to carry out the dissemination and enlightenment for the users in connection with their observance of check and maintenance of motor vehicles, the use of proper fuel, and so forth.