Mercedes 45-state diesels become 42-state diesels

<div class='quotetop'>QUOTE(Tideland Prius @ Aug 26 2007, 11:03 PM) [snapback]502593[/snapback]</div>

The point of buying a Mercedes CDI Bluetec diesel right now is that they get better fuel mileage then the gasoline counterpart and have fewer total emissions. It is only NOx that keeps the diesel out of CARB states but total emissions are lower than the gasoline model.

Actual EPA test result from http://www.epa.gov/otaq/crttst.htm / mpg from www.fueleconomy.gov

GL450 (Gasoline)
CO - 0.73
NMOG - 0.0222
NOx - 0.022
Total - 0.7742
Fuel Economy 13/15/17 mpg

GL320 CDI (Diesel)
CO - 0.04
NMOG - 0.0032
NOx - 0.48
Total - 0.5232
Fuel Economy 18/20/23 mpg

(PM is only 0.003 because the CDI's have particulate filters, the EPA T2B10 standard allows 0.080)
This is why you can't just look at the Air Pollution Score of a vehicle to see what it's emission really are. The Air Pollution Score assumes that the vehicle emits the maximum allowed pollution for its bin.

 

Correct if I'm wrong but less pollution from ALL chemicals should be the goal.

Also, is it true from the limited reading I've done that you fill this urea tank with almost 7 gallons every 11,000 miles? cost? Exclusive to a dealer/avalibility? Can wrong substance be filled by accident? Any surveys indicating the public's opinion of this clean-diesel system? Maybe I just need to visit my local Mercedes or VW dealer for some real-world scenarios...

That seems a bit complicated...but if that's the system for cleaner diesel, then people will have to weigh that option vs. a pretty simple clean hybrid, my opinion only, of course.

 

<div class='quotetop'>QUOTE(finman @ Aug 27 2007, 08:43 AM) [snapback]502676[/snapback]</div>

I agree but CARB does not. CARB and the EPA are very rigid when it comes to emission standards. I compare the standard to a box and the measured emissions to 5 sticks. I doesn't matter how small 4 of the sticks are, if the fifth stick does not fit in the box by even a millimeter than the the vehicle is banned from sale. For diesels this long stick that doesn't fit in CARB's standard is NOx. However, I find it perverse that CARB will ban the diesel vehicle that emits 48% less total emissions AND gets 33% better mileage than it's legal gasoline counterpart because they have designed a test that specifically favors gasoline technology.

<div class='quotetop'>QUOTE(finman @ Aug 27 2007, 08:43 AM) [snapback]502676[/snapback]</div>

You are confused. Bluetech is Mercedes-Benz's trade name for their new clean diesel technology. Adblue is Mercedes-Benz's trade name for Urea injection. BMW, MB, and VW were going to all use these names for their diesel technology but now BMW and VW have decided not too. Bluetech and AdBlue will now be strictly Mercedes-Benz trademarks.

Urea injection is not new. It has been used in Europe for years for heavy-duty diesels like over the road trucks and buses and recently in the US. In fact, I interviewed today with a manufacturer of transit buses, and all their diesel buses have urea injection and particulate filters now. As such urea is available at truck stops. If it used in passenger cars, it will no doubt be available in auto parts stores and gas stations just like diesel fuel additives and diesel specific motor oils are now. With Urea injection the urea consumption is 2-5% of fuel consumption. So tank size and fill intervals depend greatly on fuel economy. Europe is adding urea dispensing to their diesel pumps so you can top of your Urea tank at the same time you top of your fuel tank. I suspect in the US you will need to get it in bottles from a parts store or have it filled at the dealer.

However, NO passenger car, truck, or SUV in the U.S. uses Urea injection today. It is not required to meet current 42 state emission standards. VW and Honda have announced that their diesel passenger cars will not need urea injection to meet 50 state emission standards but instead will use a catalytic converter. Urea injection may be needed to meet the next standard that goes into effect in 2010. It may be needed for SUV's because a catalytic converter can only treat a certain volume of exhaust gas at a time and SUV's of course have much larger airflow due to their large engines and poor mileage. M-B is not going to add urea injection to their diesel SUV's until it is required to meet standards in all 50 states. Until then they will simply ignore the 8 CARB states and continue to sell them gasoline engined vehicles that pollute more and get worse mileage.

<div class='quotetop'>QUOTE(finman @ Aug 27 2007, 08:43 AM) [snapback]502676[/snapback]</div>

Yes, it is more complicated but not really much more complicated than a gasoline car. For example, VW's 2008 TDI will have a catalytic converter. This is big news for the diesel community because diesel vehicles have never had them, but gasoline engines included our Prii have had cats for decades. The particulate filter is really the only new technology and again those have been used in Europe for about 5 years now.

 

I'm learning as fast as I can here about diesels! thanks for the info.

So, what's it take to create this urea? Probably some electricity, some chemicals, etc.? so the diesel is cleaner and more efficient...but in an overall compare, do all the requirements to get clean diesel still compare favorably to gasoline? Playing devils advocate here.

It seems there's alot of "stuff" that has to happen in order for diesel fuel to fit in this "box" of emissions requirements.

And I think it's been mentioned that gasoline cleanliness has been refined with lots of time and $$...and diesel cleanliness has been ignored?? At least in the US?

Hybirds have gained a pretty good foothold in the public's eye (efficient and clean). Diesel is still a 'black' eye to the public.

How many large-scale trucks do I see EVERY day spewing black stinky exhaust?? too many to say that this is the answer.

 

<div class='quotetop'>QUOTE(finman @ Aug 27 2007, 07:43 AM) [snapback]502676[/snapback]</div>

I empty my personal urea tank four or five times a day!
(Sorry, couldn't resist)
Can you use your own "personally generated urea" in your Mercedes? Makes those highway rest stops much more eco-friendly.

 

<div class='quotetop'>QUOTE(cwerdna @ Aug 27 2007, 10:05 AM) [snapback]502539[/snapback]</div>

I believe the article is wrong.
The title should be "Mercedes 45-state diesels become zero-state diesels".

My understanding is any diesel passenger cars should meet the Tier 2 Bin 5 emissions standards in all states for 2007 or later models.
Please correct me if i'm wrong.

Ken@Japan

 

<div class='quotetop'>QUOTE(ken1784 @ Aug 28 2007, 11:22 AM) [snapback]503250[/snapback]</div>

You are incorrect for EPA standards. The EPA temporary bins 9,10,11 will be phased out after the 2008 model year. So starting in 2009, all vehicles must meet Tier 2 Bin 5.

You are correct for CARB standards. CARB require a standard that is similar to the EPA T2B5 standard for 2007. This is why the M-B diesels are not sold in CARB states.

I think that M-B's decision to ignore the CARB market makes sense. Their diesel vehicles meet emission standards for 42 states and Europe. Why would they spend the time and money to reengineer their vehicle to make a special version for 8 US States?

Politics and ego come into play too. The Germans are strong believers in diesel technology and have pointed out many times to CARB and others that their diesels pollute less than the gasoline engined models and get better mileage. CARB has proven to be inflexible with NOx emission regulations so M-B has chosen to ignore CARB markets.

 

Thank you for the correction.

Ken@Japan