FROM being seen as the future, diesel engine cars are now suffering a backlash as governments seek to comply with clean air regulations. Diesel engine emissions are now blamed for the increased levels of nitrogen oxide (NO2) emissions. Previously, environmental issues were based on carbon emissions which meant petrol-powered vehicles were measured as less environmentally friendly than diesels.
Coupled with their superior fuel economy over their petrol equivalents, diesel powered cars rose in popularity to the point where there are now well over 10 million on the road in the UK. This rise was helped when the government decided to change vehicle taxation to a CO2 based system favouring diesel cars – a move a former Labour minister now reckons was ‘the wrong decision’.
The current dilemma
The International Council on Clean Transportation has found that the levels of NO2 – emitted by diesel vehicles – is some seven times higher than those contained in EU directives in some places. The NO2 limits were exceeded significantly in various locations in several European cities including London where seven sites exceeded the limit.
The Paris mayor declared she ‘wants diesel cars out of Paris by 2020’ and UK MP’s are considering plans to introduce a scrapping scheme with incentives for diesel car-owning motorists to get rid of their cars for something cleaner. Other camps are suggesting employing something similar to hypermilling, or even altering the highway code in order to force more economic driving – although this could impact heavily on theory tests and would be much harder to push through.
There is a groundswell of opinion saying the CO2 car taxing system should be revised so petrol cars are no longer taxed as highly as diesels, and some councils are already hitting diesel drivers in the pocket. Islington council now charges diesel vehicle owners £96 on top of the existing residents’ parking price – a move which has angered some residents who say the council had encouraged its residents to buy diesel cars with its emission-based parking scheme.
Another area in which diesels are coming in for criticism is in particulate matter emissions. Although many diesel vehicles have a particulate filter, they rely on the vehicle being driven relatively long distances so the filter heats up and works properly. People doing low mileages and stop start driving journeys have filters that basically don’t work as they should and, thus, are emitting particulates.
The motor manufacturers’ view
The Society of Motor Manufacturers and Traders (SMMT) claims the government is making far too much of the NO2 issue and is unfairly blaming diesel cars for the emission problems. It says that, far from being the main culprit, diesel cars’ emissions are dwarfed by other activities such as electricity generation, heating and non-road transport such as shipping.
Diesel engine technology has improved dramatically. The SMMT has said that today’s diesel engines are the cleanest ever that that particulates and NO2 emissions are down 84 per cent since 2000.
Still, the fact that diesel is more expensive at the pumps than petrol and that the gap between the fuel economy savings is narrowing means petrol car sales could rise again before long, especially if the political mood continues to turn against the fuel.
Given that many people were encouraged to buy diesel cars for their efficiency, it may be seen as being unfair but, fair or not, drivers need to be braced for a change in the mood.
