DB22

Another study published by green transport think-tank Transport & Environment and supported by data from Emissions Analytics, suggests that about nine in every ten new diesel cars exceed the legal limit. It showed that of the 24 cars tested, only three cars - an Audi A5, a VW Golf and a BMW 3-series - complied with EU regulations. At the other end of the scale, an Audi A8 emitted 22 times the limit.

Source and article:

Diesel cars: What's all the fuss about? - BBC News

It's curious that Audi diesels are one of the best and one of the worst?

John Simcox

.....and if you actually look at the report being quoted they fail to actually list the cars and their results. I fear this is another case of a report with a predetermined agenda being based on flawed data. Unfortunately they don't show the data so you cannot tell

DennisMitchell

If you look at european Audi and others engine offerings, there are diesels and there are clean diesels. In the US only clean diesels are permitted on new vehicles. Europe should follow the US lead and permit only clean diesels in new vehicles.

DB22

Very true and I agree. It is very curious that the EU has 54% sales in diesels and the US has 0.8% but the EU has the lax rules and the US have the stringent rules.

Conclusion is that the manufacturers would rather have your money now than save your life and get it again later.

John Simcox

As of September 1st all new Diesel cars sold in Europe must be Euro 6 compliant (ie Clean Diesel) and in the case of engines 2.0 or more that means having the AdBlue system. Part of the issue in Europe is that there are so many older diesel vehicles and they are the ones that cause most of the pollution issues. We also have had previously legislation that fixated on CO2 emissions to the exclusion of anything else so that (apart from the S6 and RS6) we cannot buy a petrol engine A6 in the UK, even if we wanted to.

DB22

That is why most of the cars sold in the UK are under 1998cc. You have to be a politician to understand the logic of these decisions.

John Simcox

There are a lot of other reasons why most cars in the UK are 2.0 or less with the main one being fuel costing the equivalent of somewhere between $6.50 and $7.00 for a US gallon and punitive taxation (both vehicle tax and also benefit in kind tax for those with company cars) based on CO2 emissions

Fahrer

Many countries have higher taxes or higher vehicle registration fees for cars with 2.0 L or larger. Therefore many engines are 1999 cc or less.

2014a6tdi

DB22, if you are really curious about Diesel pollution there are a few fantastic resources available. In essence with Diesel there are two major factors that are interesting.

1) Particulate Matter (2.5PM mostly), diesel combustion. DPF addresses this.
2) NOx. Prevalent in very lean fuel-to-air ratios. Adblue addresses this.

As far as statistics in our own backyard, look at california PM 2.5 numbers circa 2008. You probably recall that when during the housing bust when everyone was saying, you cannot do this, everyone will go out of business! Anyways, truckers at that time were forced to add DPF to their rigs (I don't recall when adblue became compulsory) and check out the 2.5PM stats since then, pretty striking difference.

It wouldn't surprise me as gas cars go higher compression and continue to lean the fuel/air mixture further to start seeing them outfitted with ad blue too. Ultimately, gas competes with zero emissions technologies and the bar will continue to move towards zero emissions until its cost prohibitive to go with gas/diesel.

I feel very good, environmentally speaking, about the diesel car I purchased and where the technology is headed. The morons "rolling coal" (rich mixture/no dpf) do diesel adoption a huge disservice.

DB22

I assume that you are referring to the demise of gas/diesel as being replaced with electric? This will require more power stations which will pollute so it will promote solar. Elon Musk is the one with the broad smile on his face

I must admit, however, that if you ride your bike in a majority diesel city then you learn to hate diesels but the A6 is impressive: no smoke and no smell of note.