I thought this might interest some of the smogmonster drivers out there, gives an idea of Euro emissions levels. Sorry for infringing copyright, if its any consolation I'd recommend a subscription to PE magazine to anyone, its a very interesting read.

Dust busters

The designers of diesel engines are aiming to see the back of clouds of tiny particles billowing from exhausts. But its proving a difficult challenge. Richard Butler explains

Pollution from traffic is a concern for anybody who has to live or work near a busy road. Over the past 14 years, European emissions standards have tried to push carmakers into producing cars that are more pleasant to be around.

With each set of emissions regulations, the European Union raises the bar that bit higher. The first couple of these hurdles could be overcome by tweaking with injection timings and other methods of achieving more efficient combustion. But, with each stage of targets, new technologies are having to be added to help overcome the challenge.

Part of the need for this application of technology has come because of a shifting emphasis as the stages have progressed. At first, the regulations focused on reducing carbon monoxide but as they have gone on, the focus on oxides of nitrogen (NOx), and particulate matter has increased.

This is a particular challenge for makers of diesel engines, which tend to produce more particulate matter than petrol engines. Up until now, the carbon monoxide and unburnt hydrocarbon limits have been reached through optimising engine design. Introducing more oxygen, along with higher temperatures and pressures in the combustion chamber, has increased the likelihood of complete combustion of the fuel. This has minimised the output of unburnt hydrocarbons and carbon monoxide, which are the result of incomplete combustion. But the side effect of this increase in oxygen and temperature is that the engine becomes hot enough to start to combust the nitrogen in the air, leading to the formation of NOx.

Consequently, it isn

Petrols produce particulates too, just wait until they start on the petrol engine.

The way oil is going, you might have 20 more years of petrol/diesel before things really start to get serious.