The division bench of Chief Justice Y K Sabharwal and S H Kapadia further said that all private vehicles which are registered in Mumbai after January 2001, will have to conform to the Euro-II norm.

The interim ruling comes in the wake of a public interest petition filed by the Smoke Affected Residents' Forum, which highlights the alarming increase in vehicular pollution in the city. It has called for stringent action against private vehicles which do not follow pollution control norms as laid down by the Supreme Court in the case of vehicles in New Delhi.

The petitioners were today joined by a group of doctors and other concerned citizens whose intervention applications were accepted by the division bench. The matter will be heard next on October 8. The respondent andpetitioner parties have been given three weeks time to add necessary details.

According to the intervenors, 40 per cent of Mumbaikars suffer from respiratory disorders like bronchitis and asthama while the state loses about Rs 18,000 crore per year due to the manhours lost due to pollution-related illnesses and reduced productivity levels. The intervenors also claim that 60 per cent of air pollution in Mumbai is attributable to vehicles.

The automobile industry, car-owners and the state government have meanwhile welcomed the Bombay High Court's landmark ruling. Mumbai will now become only the second city in the country after New Delhi to make pollution-controlling automobile engines mandatory for newly registered private, non-commercial vehicles.

However, as with Delhi, it is once again automobile giant Maruti that is likely to be most affected by the new rules. While all other new car models like the Indica, Cielo, Santro, Matiz and the Siena which are sold in the city are Euro-I compliant, Maruti,which accounts for the bulk of car sales here, is yet to start offering the Euro-I compliant engine. Even Fiat, which supplies the 137D model without the Euro-I norm, will be affected.

Maruti Udyog only recently began supplying Euro-I engines in the Delhi National Capital Region following a Supreme Court directive earlier this year making the sale of such engines mandatory.

``It is an excellent ruling, if it can be achieved in Delhi, it can be done in Mumbai too,'' says Transport Commissioner V M Lal.

However, the Western India Automobile Association (WIAA) President Nitin Dossa says the introduction of Euro-I and -II norms, though welcome, would not make a difference unless adulteration of petrol is stopped. ``Even Euro-5 is incapable of stopping pollution if it is used with adulterated petrol,'' he says.

India 2000, as Euro-I has been redesignated, basically replaces the old carburettor (which mixes the fuel and air) with a multi-point fuel-injection (MPFI) system controlled by a tiny computer chip.The system boasts of greater engine performance, fuel efficiency besides drastically reduces emission of pollutants.

``It will make life easier for all of us, the cars will perform better and pollute less,'' says Ajit Kamlani of the Petroleum Dealers' Association (PDA). He says with the phasing out of the carburettor and the distributor in MPFI engines, the days of the roadside mechanic opening the bonnet and repairing cars, will be over. But service stations too have to be upgraded to deal with the new technology.

``We don't want new rules and regulations, we want the implementation of the existing laws,'' says Dr Sandeep Rane of the Smoke Affected Residents Forum, one of the petitioners in the case.