Exemption is unfair, say some carmakers and dealers
NEA said last week that petrol cars with port fuel injection won't be tested for particulate matter emission
A number of carmakers and dealers are crying foul over a surprise move to exempt some models from getting particulate matter (PM) readings.
It is counterproductive to the Government's aim to reduce PM - or fine soot - in the air, they said.
The National Environment Agency (NEA) made public last week, in response to queries from The Straits Times, that petrol models with port fuel injection (PFI) will not be tested for one of the five pollutants.
The news came two months after the NEA announced a new car emission scheme that takes into account five pollutants, including PM.
NEA said petrol models with PFI - where fuel is injected just before the engine's combustion chamber - will not be measured for PM when the Euro 6 emission standard kicks in in September, and when the Vehicular Emissions Scheme (VES), which dishes out tax rebates or surcharges according to a car's emission levels, starts in January.
It explained that the European Commission makes a similar exemption for PFI models, citing the PM emissions from these models as being "very low".
Because of this exemption, a car like the Toyota Corolla Altis, which employs PFI, could enjoy a tax rebate while a similar model such as the Mazda 3 would be slapped with a surcharge.
This could make the Mazda 15 to 20 per cent costlier.
Sales director David Pang from Alpine Group, which sells Opel and Chevrolet cars, said: "Exempting one group of vehicles from what is a key pollutant count will just create unfair competition."
Meanwhile, PFI technology is deemed to be less fuel-efficient and could produce more carbon dioxide than direct injection where the fuel is sprayed directly into the combustion chamber.
A spokesman for the BMW Group said: "We cannot confirm that PFI always tends to produce less particulate emissions.
"This depends very much on the engine load."
He added that under high engine load, such as accelerating from a stop or overtaking, "the particulate emissions of engines with direct injection can be equal or even lower than those with PFI".
A 2012 European Commission study said there were concerns regarding the suitability of the legislated procedure for the assessment of the true particulate emissions of PFI vehicles.
"The particle number emissions of PFI vehicles are found to strongly depend on the driving behaviour," it said.