black1444

Emissions wise, how do diesel cars compare to their petrol counterparts? I know that diesels are more efficient and emit less Co2.

However the E320 CDI got 1/10 for the EPA pollution score. Is that because diesels emit too much particulate matter?

Thanks.

ImolaRedM

Yes. But it depends on the fuel you use. The current diesel used in the US is heavy in sulphur. Within the next year it will improve. If you use Biodiesel you can greatly cut all other emissions with the exception of NOx.

Ricracing

New BMW diesel has the particle filter and that really makes the engines clean.
The mirco particles are the worst that diesel engines produces!

I.e. the new 520d only produces only Co2 158 g/km, and thats great.

Compare to the 523iA and 530iA (224) and the 550iA (260).
The 530dA produces Co2 200 g/km.

535D Sport

It states in the owners handbook that you should not use Biodiesel as you risk causing damage to the engine.

drjochen

Biodiesel has different viscosity and is a bit more agressive to gaskets etc.
Also, the composition of NOx, CO, and unburned hydrocarbons is different for a Diesel. When we test mateials in my lab, we use different amounts of these gases. In principal, the Diesel exhaust is closer to the lean burn gasoline exhaust that to the stoichometric exhaust. Diesel exhaust also has more organic compounds including hydrocarbons such as aldehydes, ketones, benzene, etc., which need to be oxidized.

In addition, Diesel engine exhaust has a lower temperature than gasoline engine exhaust, which leads to light-off issues etc.

Ricracing

Seems that you, drjochen, are into pollution and chemtech

Is that the reason why you will trade in your 545i to a 530i?

Anyway, the finest thing with diesel engines is that they burn energy
much more efficient than gasoline engines ever.

But as said they produce a vast amount of toxics of which the partcile filter
can handle the most?

A fact is also that in the US the diesel fuel is not enough raffinered to meet the
standards of modern turbo-diesel cars.

Maybe now when the gas prices will go over $3 / gallon, the diesel fuels and pump
stations will come the the new continent?
But probably not - yet :thumbsdown:

KAF

The US is more concerned with NOx than CO2.
Until either that changes and they start to worry about CO2, (probably when Florida floats off into the carribean), or Diesel engines can meet the NOx emmision regs, sooner than the above I should think, Diesel is unlikely to take off in the US.

Then all they have to worry about is the tax level!

drjochen

Indeed, I am a Chemical Engineer and I actually do research in automotive exhaust.

The Diesel is not much worse than the Otto engine in terms of emissions except the particulate.

We really need to separate CO, NOx, HCs, etc. from particulate. Two different things, two different ways to treat (the first with a catalytic converter, i.e., storage and reduction system or selective catalytic reduction system) and the second with either filters or catalytic filters.

skaffa

Taken all in consideration, which will save the world??

-Otto motor which higher consumtion, but less dangerous (?) emissions

or

-Dr. Diesels motor whit better efficiency, but more dangerous (?) emissions

Or all this is political?!

Skaffa

KAF

Apparently, if you could stop all the cows in the world from farting, the reduction in Methane emissions would enable us to keep puffing CO2 into the air from our cars without worry.

Bound to be an easier solution than getting the USA to reduce use of cars.