Yes "clean diesel" really is clean. (ACEEE.org)

[theaveng]

The American Council for an Energy-Efficient Economy has given the 2012 Jetta TDI a green score of 48. The Golf, Beetle, and other cars using the same engine also scored 48. This makes the Jetta and other TDIs cleaner than nearly all gasoline cars on the road (except the Chevy Cruze ECO which scored 49).

[jonnyvtec]

They must use an 'interesting' metric for quantifying clean?

WHO (World Health Organization on 12 June 2012 reclassified diesel exhaust from a 'probable carcinogenic in humans' to 'carcinogenic in humans'.

There's a report in January 2013 engine international magazine. It does seem they used the old EU2 standards for exhaust though.

[theaveng]

Originally Posted by jonnyvtec

They must use an 'interesting' metric for quantifying clean?

Not really. The ACEEE is using California's smog designation for the TDI of "ULEV-II". That makes it just as clean as our 1st generation Insights and leanburn Civic Hybrids (also rated ULEV). Several things have changed to make TDIs cleaner:

- Diesel had the sulfur removed so it's as clean as gasoline now
- That enabled better catalytic converters equal to those in gas cars
- And there's a soot trap to capture & burn off the particulate matter

Hence the ULEV-II designation by the CARB. Ford claims its diesel Focus would qualify as a SULEV if they brought it over from Europe to America. Honda makes the same claim for its diesel Civic.

[theaveng]

I hear the Cruze Eco doesn't have a spare tire (in order to reduce weight).

[jonnyvtec]

Originally Posted by theaveng

Not really. The ACEEE is using California's smog designation for the TDI of "ULEV-II". That makes it just as clean as our 1st generation Insights and leanburn Civic Hybrids (also rated ULEV). Several things have changed to make TDIs cleaner:

- Diesel had the sulfur removed so it's as clean as gasoline now
- That enabled better catalytic converters equal to those in gas cars
- And there's a soot trap to capture & burn off the particulate matter

Hence the ULEV-II designation by the CARB. Ford claims its diesel Focus would qualify as a SULEV if they brought it over from Europe to America. Honda makes the same claim for its diesel Civic.

What sort of NOx though as thats where diesels struggle. Hence EU6 & LEV160 will require Urea + SCR on most diesels and PM continues to be a struggle to manage!

[theaveng]

Originally Posted by jonnyvtec

What sort of NOx though as thats where diesels struggle. Hence EU6 & LEV160 will require Urea + SCR on most diesels and PM continues to be a struggle to manage!

(sigh). I truly don't understand. Why do people have such a hard time grasping the "diesels are cleaner now" concept? Diesel engineers aren't just sitting on their butts doing nothing. They are improving the engines to make them cleaner. TO ANSWER YOU: Ya know how our insights produce high NOx levels (via lean burn) and the catalyst traps & neutralizes it?

Well. That's what the diesels do as well. That's why even though ULEV qualification requires them to output very little NOx and very little PMs, the modern TDI cars received the rating from California's Air Resource Board.

Another major change is the fuel itself. Diesel only has 15ppm of sulfur, which makes it cleaner than gasoline (50ppm).

[jonnyvtec]

Originally Posted by theaveng

(sigh). I truly don't understand. Why do people have such a hard time grasping the "diesels are cleaner now" concept? Diesel engineers aren't just sitting on their butts doing nothing. They are improving the engines to make them cleaner. TO ANSWER YOU: Ya know how our insights produce high NOx levels (via lean burn) and the catalyst traps & neutralizes it?

Well. That's what the diesels do as well. That's why even though ULEV qualification requires them to output very little NOx and very little PMs, the modern TDI cars received the rating from California's Air Resource Board.

Another major change is the fuel itself. Diesel only has 15ppm of sulfur, which makes it cleaner than gasoline (50ppm).

The cost of NOx capture has always been prohibitive, Honda managed with their excessive material cost and low power engine with no profit margin. It's these aftertreatments that are pushing Europe back to petrol for the smaller cars as they simply can't hide the cost on non premium vehicle so a large difference in price is appearing between petrol and diesel models of the same car.

It's not how diesel do it anyway, for EU6 they are injecting urea into the exhaust not capturing it. As your in the states I'll forgive your understanding of diesels as here in Europe they are turning out to be total pains to run and own. They have a multitude of complex expensive parts. DPFs that frequently clog and can not regen, injectors and high pressure pumps that fail and dual mass flywheel that fail.

The low pressure EGR systems that rely on post DPF gas are even introducing valves in the exhaust to increase back pressure to promote exhaust gas recirculation to the combustion chamber, all these thing are also impacting the efficiency of the engine.

I agree they are getting cleaner, not really like a good petrol though as that now enters an exciting period of development.

[E27006]

Here is a link to Wiki for emission levels for Euro 1 to 6.

looking at Nox figures it would seem the diesel engineers were not held to account until rather late in the day, look at the figures for Nox for diesel euro 1 to 5.
Euro 6 limit for Nox due in 2014 is causing a few headaches as Jonnyvtec highlights, yet the 0.080 figure was met for petrol in 2005.

European emission standards - Wikipedia, the free encyclopedia.

There is also the issue of the issue of low refinery yield from fossil fuel, 20% for diesel, 40% petrol.

In reality no car is clean, that term is reserved the bicycle, sadly one of Britains leading car and bicycle engineers, Dr Alex Moulton, passed away last Sunday age 92, active to the end, he worked with Issigonis on the Mini and many other until the 1990s, his highly regarded bicycles, 200,000 + sold.

He became eco-minded later in life, one aspect, gave up his Bentleys etc for the Prius

http://www.bbc.co.uk/news/uk-england-wiltshire-20691388


Dr Alex Moulton, the pioneering British engineering behind the small wheel bike and the Mini's suspension dies aged 92 | Mail Online

[theaveng]

TDIs don't seem to have any problem passing CARB's stringent NOx requirements. They were "banned" in 2005 but the latest ones are rated ULEV cleanliness.

Originally Posted by jonnyvtec

It'for EU6 they are injecting urea into the exhaust not capturing it. As your in the states I'll forgive your understanding of diesels as here in Europe they are turning out to be total pains to run and own.

That's funny you say I don't understand. I OWN a diesel. And the urea is Not for NOx neutralization. You were wrong on that.

And diesel sales in Europe are going UP not down, nearing half of all cars sold. And for good reason: They get 50 to 60mpg and diesel has a lower tax so it's cheaper per gallon.

I'd rather have an efficient diesel in my hybrid or Volt EV then an inefficient gasoline engine that gobbles 1/2 more gasoline. If the gasoline engine in my insight was swapped-out for a 1.2L 3-cylinder TDI, its EPA rating would increase from 61 to 81 mpg.

[jonnyvtec]

I dont own a diesel so I guess you must be right....

I best go down to the calibration cell on the latest TDV6 engines though and tell them not to bother with the urea injector cals and stop the fuel systems team packaging a urea injection system into the MY15 cars ready for EU6 and LEV160 as it doesnt reduce NOx according to some dude on the internet.

Even Wikipedia will tell you enough about SCR. Youv;e kind of lost credibility starting off with a claim about urea not being for NOx reduction!

The problem is that you have assumed when I said manufacturers are developing petrols for smaller cars you think I'm referring to cars sold today.

I'm talking about the upcoming emissions where B and C segment cars can no readily absorb the cost so you end up with a higher price car that post depreciation and extra servicing was no cheaper to run than a petrol over the 8k miles the buyer ran it. THEN we will see a change in buying profiles. Not to mention the cost of filling the urea.

Also the price of diesel is set to rise over coming years due to the refining fraction from a barrell of crude and diesel demands increasing.

I'm not really sure where this conversation was going anyway, but there's little merit adding anymore.