"You live in a caucasian enclave" I live in a suburb of a major city, not unlike every other suburb. Woop-ty-do.

"have openly stated your hatred for people who are not caucasian" Total LIE, never happened, not true at all.

"blaming them for a variety of social ills" I stated some facts, sorry that doesn't fit your political feelings.

In ten years a small number of possibly undermaintained clean diesels that are 30% more effecient than what they are driving now. Frankly I'm more concerned about what you and I will be driving.

I live in a suburb of a major city, not unlike every other suburb. Woop-ty-do.

Nice dodge. The particular place you live is fundamentally dissimilar in its racial makeup from proximate places comparable in size.

Total LIE, never happened, not true at all.

Keep telling yourself that.

I stated some facts, sorry that doesn't fit your political feelings.

There we go. There's the true you. You didn't state facts, you stated your interpretation of your unsubstantiated claims. Being disgusted by racism is apolitical.

In ten years a small number of possibly undermaintained clean diesels that are 30% more effecient than what they are driving now.

"Clean" diesels? The only thing that makes them clean is the urea. Without it, they're extremely dirty. As for small numbers, I didn't realize you knew how well these vehicles with this technology will sell. Are you a time traveler? It's also irrelevant, since the only reason one should get behind diesels is because they'll make a dent in fuel consumption, and if they're sold in small numbers, there's no point. Regardless, there's no reason at this juncture to be putting out vehicles which have the capacity to be extremely dirty in a few years.

@ Jack -

most European heavy truck manufacturers decided to adopt urea injection to meet Euro 4 emissions, which came into force in 2005. It takes a few years for the HDV fleet to churn, but new models featuring this technology are already a common sight.

If anyone has an incentive to cut their cost of operation by defeating an emissions system, it's truckers. Yet, thanks to the sophistication of EOBD, such cheating is not worth the hassle. It doesn't appear to be an issue.

EOBD is the European version of OBD. Generally speaking, it's stricter than OBD I but not as paranoid as OBD II. Refilling the urea solution is not regular maintenance like changing your engine oil, which you can forget or choose to defer - if you run out of urea or substitute another liquid, the OBD will enforce the action the law requires in that situation.

Your right, the ULSD, high pressure common rail, optimized compression ratio, recirculatory system and Particulate Filter are all just show pieces. Right!

I think jack brought up a good point about the relative vulnerability of the urea SCR system due to negligence in maintenance due to general car garages' or second-hand owners' lack of familiarity with the system.

Image a soccer mom who happens to inherit this sophisticated diesel car, who brought it to the likes of Jiffy-lube for oil change...and the trainee technician /assistant went to the routine to change oil and filter, but oops, it's not his habit to refill the Adblue tank...The warning light lit up later, but being a mechanically-challenge mom of 4 kids, she neglected the warning light entirely until the car won't start at the most inopportune moment...like in the middle out of nowhere in a snow storm...

But, there is a kinder and gentler way for the car to address the depletion of the Adblue tank other than flat out refusing to start: The car can switch to low-power lean-running mode with inherent low NOx emission...the car will barely run...enough to get home and to get to the dealer the next day...
Or the owner can decide to run on low power low NOx mode until the next inspection interval...

Anyway, the beauty of the urea SCR system is its high effectiveness while using no expensive nor any rare catalyst that will limit future availability. For that, MB deserves an environmental gold medal!

T2B5 could be met, maybe beaten, more easily if the low cetane (~42?) ULSD supplied at present were improved to near 50. Why are cetane stickers missing on virtually every diesel pump out there? This "dirty" little secret needs to see the light of day.

Cetane numbers have nothing to do with meeting emissions. Too high of a cetane can cause the diesel to ignite too quickly and not mix, causing high NOx and PM.

My thesis research is showing that we may want low cetane to help with running LTC.

It all depends on the combustion mode and more than likely LTC will take over so we will need to reevaluate the fuel needed for this.

most European heavy truck manufacturers decided to adopt urea injection to meet Euro 4 emissions, which came into force in 2005. It takes a few years for the HDV fleet to churn, but new models featuring this technology are already a common sight. If anyone has an incentive to cut their cost of operation by defeating an emissions system, it's truckers. Yet, thanks to the sophistication of EOBD, such cheating is not worth the hassle. It doesn't appear to be an issue.

On the contrary, they have a strong disincentive, since there isn't much to the cost and the last thing a commercial enterprise is more interference and potential penalties from government agencies. Contrast that with someone driving an SCR beater diesel 10 years from now. How are they directly regulated by the state, especially in a state without emissions testing?

I think you don't really grasp the kind of free-for-all out there in many states when it comes to people either neglecting vehicle upkeep or outright circumventing control systems for greater performance, more noise, or whatever.

I'm not worried about freight operators, I'm worried about the guy whose car goes down the road, tail scraping against the ground because he's too lazy, cheap, or poor to put new shocks on it. That's the guy who won't do a damn thing with some urea tank.

Clearly the EPA isn't quite satisfied yet, otherwise we'd be seeing these vehicles coming to market.

Don't get me wrong. I'm very happy to see diesels with proper tailpipe emissions. I just know how people deal with their rides and it causes me concern.

Jack,

I just called Mercedes USA and asked them. They told me that after a limited number of starts with an empty AdBlue tank, the car would not start again until being refilled. The rep could not tell me how many "limited" was.

Again, this system seems to only be implemented on high dollar vehicles, so that means low volume. I agree that, in 20 years, some of these already rare vehicles will probably end up being jalopies which have been ECU hacked. But they could only continue operating if the state they are in still has completely lax inspection rules. So that narrows down the possible numbers to very, very small. Certainly not enough to justify not bringing this and other clean diesel technology to market. Nothing is perfect, and I don't see a glaring red flag with this system either.

In my opinion, NOX is not what you should be worried about, small particles are what you need to be worried about. Since the new particle filters are on all of these cars, that worry has been addressed in a mostly permanent way. Yes, these filters and exhaust systems will deteriorate over time, but that happens on any vehicle, regardless of fuel.

Jack, would it be possible for you not to be so hostile towards other posters? Its ok to engage in reasonable discourse, but you seem to cross the line a bit more frequently than anyone else here. Just my observation, so please don't take this as an insult.

Welcome to GCC, "George J."

Thanks. I'm glad I found this site. They seem to get new car info much faster than the typical car enthusiast site. And if it wasn't obvious, my screen name is a nod to my favorite idealized world of personal transport: The Jetsons.

And if it wasn't obvious, my screen name is a nod to my favorite idealized world of personal transport: The Jetsons.

Good one.

Though the idea of flying cars is fanciful (and nightmarish ala "Fifth Element"), it would be refreshing for more people to think about breakthrough ideas instead of plodding incrementalism applied to overly-mature technologies. This site is quite good for what it is, but it does get bogged down in mypoic back-and-forth from primarily an engineer's way of looking at the world.

Welcome.

Yea, or Bladerunner.

One thing about the new diesel particle filter systems. None of the manufacturers are allowing more than B5. They are claiming that when the filter has to regenerate, higher percentages of biodiesel can gunk it up. They regenerate by sending extra fuel down the line to ignite in the filter and super heat it. This burns off the collected particles. Biodiesel does not ignite the same way as diesel, so they will only allow B5.

This leaves me torn. Along with the efficiency gain of the new diesels, I wanted to be able to burn biodiesel in higher percentages.

@Jack -

I get the impression you're not familiar with how an OBD works and how incredibly difficult it would be to hack it.

Air quality is a common good. If certain states cannot be bothered to protect it, that's probably because the people who live there don't want to pay for it. It's their air, so it's their choice. No amount of legalese will make the slightest difference if people don't want the law to be enforced.

I get the impression you're not familiar with how an OBD works and how incredibly difficult it would be to hack it.

4) Tamper Resistant Design. Manufacturers would have to demonstrate to EPA that their SCR system design is tamper resistant. There are three aspects of a design that we would want to see made tamper resistant:
• Warning System - The visual and audible components of the warning system should be as tamper resistant as reasonably possible.
• The Driver Inducement Design - Tamper resistant features will be needed to ensure that the driver inducement system cannot be easily disabled. The specific requirements will depend on the driver inducement design. For example, the fuel door cannot be pried open for a fuel lockout system or the ability to start the vehicle with no reducing agent for a no-start design.
• The Reducing Agent Dosing System - Ensure that the dosing system cannot be easily deactivated, for example, by disconnecting the electrical connector to the dosing valve.

http://www.epa.gov/otaq/cert/dearmfr/cisd0707.pdf

The EPA covers pretty much all my concerns in that document. Since we're not seeing these rolled out 50-state as purchasable vehicles until later next year, I assume the EPA still is working to make sure those concerns are addressed by the manufacturers.

My main concern isn't with intentional hacking of the system but rather simple neglect.

Air quality is a common good. If certain states cannot be bothered to protect it, that's probably because the people who live there don't want to pay for it. It's their air, so it's their choice. No amount of legalese will make the slightest difference if people don't want the law to be enforced.

Wow, I don't even know where to start with that one, other than with the out-of-bounds assumption that somehow people are informed about things like air quality, understand what to do about it, and most importantly, CAN do something about it. If we had a functioning, model democracy, what you said might make sense, but in the real world, it is unfortunately more than common that those who set policy aren't doing so to benefit the largest number of citizens - particularly those with the fewest resources.

With the kind of argument your making, it doesn't differ much from some refiner knowingly pumping carcinogens into the air and brushing it off by saying, "Well, it isn't illegal." We know better now, so it shouldn't be an issue of what one can get away with but rather doing one's best to be as benign as possible.

Rafael,

I was just thinking that it would be as easy to hack as all the performance hacks that people make to their ECUs. For those, the whole OBD system has been a boom, letting them use laptops to change engine settings on the fly.

Couldn't you theoretically do the same for any aspect of the ECU programming?

Does anyone know which states are considered the lax ones for inspections?

This engine is underpowered for Q7 and Touareg. I test drove it in Poland last year, it is noisier than Mercedes (I drove Chrysler 300 CDI AWD for comparision) engine. For Audi most adequate would be 4.2 V8 or preferebly V12 TDI. There is not that much higher fuel consumption but performance is brisk! Due to get good performance US USDL fuel must get same cetane rating as European - 60 vice 40.

The problem with using BD blends above B5 is not specifically with the DPF, but rather, with one type of regeneration system that is used for burnoff. Some regeneration systems (VW/Audi)create an extra fuel burst in the combustion chambers to regenerate the DPF. Supposedly, if more than a B5 blend is used, some of the fuel will not vaporize sufficiently, which will leave some fuel on the cylinder walls which may end up in the motor oil This could cause a need for more frequient oil changes for those who use high blends of biodiesel.

The other type of regeneration system, which is used by MB, sends a burst of fuel directly to the DPF. In this situation, the regeneration will actually perform better as the blend of biodiesel increases. This is due to the increased oxygenation of the biodiesel fuel.

As for the actual DPF performance, biodiesel enhances the effectiveness of the DPF. *DPFs burnoff at lower operating tempertures running BD blends than is true using ULSD. With BD blends, DPFs will not develop near the level of backpressure before regeneration takes place.

The reason for the "no higher than B5 approval" is the same as in years past. The world has no set fuel standard for biodiesel blends. This situation makes OEMs nervous. They cannot test their engines with a standardized fuel when there are no standardized fuels to test them from. This is the real reason OEMs still do not support more than a B5 blend. This does not mean that higher blends are bad. I've run my 2006 Jetta TDI on B20 since inception. Supposedly, one could not use higher than B5 in this unit-injection engine as it would be detrimental to the injection system. I've had my injectors and injector pump inspected after two years on B20. Guess what? Super Clean.

In the case of VW/Audi, however, the original post on this matter is correct. Biodiesel blends do create an additional factor that must be considered for its use.

In my opinion, this new problem using biodiesel will show to be far exaggerated as have all the previous, "so called" problems.