Owners of older diesel vehicles can expect a $51 million Government subsidy to fit them with filters. The move is part of an environmental drive to reduce by six per cent total particulate emissions on the roads. The plan, pending funding approval by the legislature, would provide car owners with grants to install particulate traps on about 42,400 light vehicles of up to four tonnes built when older standards for emissions applied. In 1995, the Government introduced so-called Euro I emission standards, under which a diesel vehicle should emit about 50 per cent fewer particulates and 10 per cent less nitrogen oxide than the preceding model. A stricter Euro II standard was introduced in 1997 and the Government plans to introduce the Euro III standard next year. The $51 million grant scheme is aimed at pre-Euro standard diesel vehicles. The particulate traps cost about $1,000 each while installation would cost $200 each, the Environment and Food Bureau said. Diesel vehicles are a major source of air pollution in Hong Kong. They account for about one third of the local vehicle population and contribute to about two-thirds of vehicle mileage. About 98 per cent of the particulate emissions and 75 per cent of the nitrogen oxide emissions from the vehicle fleet are due to diesel vehicles. It is planned to start installing particulate traps before the end of the year and complete the task by 2002, the bureau said.