Vehicles with a higher capacity diesel engine, above 2000cc, which have been banned in Delhi by the Supreme Court since December 2015, do not pollute more than vehicles with smaller engine capacity, reports Malyaban Ghosh in Mumbai.
Data in a government affidavit filed with the Supreme Court shows that not only diesel vehicles with 2000cc engine and above emit Particulate Matter (PM) within the permissible limit of 0.06, but almost at same level that of vehicles with sma-ller engine capacity, 1300-1400cc. This clearly establishes that the size of the engine has no relation with pollution. It is the quality of engine which matters. A Land Rover Discovery Sport which has a 2993cc engine, for instance emits PM at 0.019 gm/km, well within the prescribed limit of 0.06.
Compare this to Renault Lodgy, which has an engine capacity of 1461cc but emits PM at 0.018 gm/km. (see chart). Simply put, there are two pollutants that come from vehicles — PM and carbon monoxide (CO). Diesel vehicles emit higher PM compared to petrol engine but lesser CO.
Therefore, according to industry veterans, banning diesel is not the option, as the Supreme Court has done. Though new-generation petrol cars are good on PM emission levels, the same is not true for two-wheelers, which also run on petrol, because they still have a carburettor engine, which leads to high emissions.