2003Ram

Not good news. Starting 2007, Mercedes will introduce Urea, a liquid that will be injected into the exhaust to reduce NOx. It won't be long before it affects light/medium duty trucks.

Link to article in San Diego paper. I don't know how long the link will be active, so the article is pasted below.
http://www.signonsandiego.com/uniont...d17diesel.html
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Mercedes sees diesel system as clean as gas

By Richard Truett
AUTOMOTIVE NEWS
April 17, 2004
SAN ANTONIO – Mercedes-Benz, the company that pioneered diesel-powered automobiles, has developed an emissions system that could pave the way for the widespread return of the diesel engine in North America.

The German automaker plans to meet tough new U.S. diesel emissions regulations scheduled for 2007 by using an ammonia-based liquid called urea.
The fluid is held in a replaceable canister on the car. It is injected into the exhaust system periodically. High heat causes the urea to neutralize oxides of nitrogen, or NOx.
Mercedes calls its system SCR, short for selective catalytic reduction. It's a scaled-down version of the system Mercedes will use on its commercial vehicles.
Many automakers are struggling with the upcoming emissions regulations, which also govern the amount of particulate matter, or soot, and require diesels to run as clean as gasoline engines.
Most automakers say they should be able to meet particulate matter standards through improvements to the diesel's fuel injection, combustion and exhaust systems. It is the NOx standard that is most troublesome.
A NOx trap, which is installed in the exhaust system, is the leading alternative to a urea system. But it has disadvantages.
The trap is expensive, and there are concerns it might not last for the government-mandated 10 years or 150,000 miles. The trap is extremely sensitive to sulfur, and it likely would reduce performance.
A urea injection system is the least expensive and most effective way to meet the NOx emissions standards, Mercedes-Benz says.
But urea also has a drawback: If the driver lets the car run out of urea, the vehicle won't meet emissions standards until the supply is replenished.
That is something that concerns the EPA.
Officials at Mercedes-Benz parent DaimlerChrysler discussed the matter with Margo Oge, director of the Office of Transportation and Air Quality, part of the Office of Air and Radiation for the EPA.
"We know the technology works," Oge says. "There is no question about it. But what we are looking at is shifting the burden of meeting emissions onto the consumer. Companies have to carefully evaluate their business plans and see if this is something that will sell to the consumer."
Oge also says there are other ways of meeting the NOx standards.
Mercedes engineers are trying to create a system that forces drivers to install a urea canister every 13,000 miles, when the car returns to the dealer for scheduled oil changes.
To ensure that drivers keep urea tanks filled, Mercedes engineers could limit the car's speed or driving range, or the number of times the engine will start once it runs out of urea. To make it easy to replenish, Mercedes is considering making the canister available at oil-change businesses and auto parts stores.
"The question is whether (drivers) can see urea in a similar fashion like engine oil or transmission fluid," says Bharat Balasubramanian, DaimlerChrysler's vice president of development and engineering technologies and regulatory affairs.
"You just fill it whenever you have the car serviced. You get this safety into the entire system, and you shouldn't have any problems. That's what we are working on right now."
During the media introduction in San Antonio of the Mercedes E320 CDI diesel sedan –the first Mercedes diesel in the United States in five years – company officials said the car marks the permanent return of the diesel engine for its North American vehicles.
Mercedes SUVs also are likely to get diesel engines.
The E320 CDI that just went on sale does not have the urea system. Mercedes plans to outfit its diesel vehicles with the urea system sometime in late 2006 for the 2007 model year. The introduction of urea coincides with the introduction of low-sulfur diesel fuel mandated by the government.
The urea system will enable Mercedes to reduce radically the cost of the emissions systems for its diesel cars while maintaining performance. A NOx trap, which uses precious metals, is not needed with the urea system, Balasubramanian says. The technology is likely to find its way into Chrysler-brand vehicles, he says.
The Chrysler group will launch a diesel-powered Jeep Liberty this year.
Mercedes-Benz is not the only company that believes urea injection has a future. Ford Motor is exploring urea as a way to meet stricter emissions standards.
Ford engineers have designed a prototype dual-fuel system that would fill a urea tank at the same time a driver fills up with diesel. But such a system would require expensive changes to the nation's diesel fuel pumps.
Ford research engineers also are working on exhaust system filters that can reduce diesel emissions.
A spokesman for Volkswagen of America says urea is not an option for the New Beetle, Jetta, Touareg, Passat and Golf, the only diesel cars offered in the United States before the E320.
VW is working on a NOx storage catalyst.
Lindsay Brooke, a powertrain analyst for CSM Worldwide in Farmington Hills, Mich., said the urea system won't be much of a nuisance to hard-core diesel fans.
But it could be bothersome for drivers who are not diligent about maintaining their cars.
The decision by Mercedes to go with urea, Brooke says, could influence other automakers that have not decided how to meet tougher emissions standards.
"Whoever fires the first shot in any technology war certainly has the attention of the rest of the industry," Brooke says.

CCM591

Thanks for the post.

This may be a non-issue by 2007. EPA seems convinced that diesels may be able to meet the NOx standard WITHOUT aftertreatment:

"…Low Emissions – Potential to achieve levels of 2007/2010 Heavy-Duty Engine and Tier 2 emission standards without the use of NOx aftertreatment…."

Source: http://www.epa.gov/otaq/technology/420f04023.pdf

"…under its Clean Automotive Technology R&D program, EPA is also evaluating unique diesel engine concepts with a goal of identifying a Clean Diesel Combustion concept that could simultaneously be extremely efficient, clean, and cost effective.…EPA has now demonstrated lower engine-out nitrogen oxide emissions levels than anything reported in the literature, and this suggests the potential for diesel engine design, using innovative air, fuel, and combustion management and conventional particulate matter trap aftertreatment, that might be able to achieve Tier 2 Bin 5 NOx levels without the need for NOx aftertreatment…."

http://www.epa.gov/otaq/reports/adv-tech/420r04002.pdf


Looks like ULSD fuel and PM filters are a given though.

linetrash75

if they start injecting urea into the exhaust i hope they put stainless steel exhuast on it . that stuff will eat thought a regular pipe within a year.

jed

NORM

QUOTE]Originally posted by NORM
As a Machinest/Welder for a Caterpillar dealer I don't work on engines, but we all attend store meetings by the engine dept of our dealer structure. We hear about what they think they know about other engine mfg's strategies and directions. EGR is one topic that is talked about, Cat has not choosen to go that way. Emission limits are being reduced by the EPA to a 2008 "box" and it has the mfg's working overtime. You could start looking at the issue here http://www.epa.gov/otaq/hwy.htm
Norm [/QUOTE]


we are just seeing the starts of this all. look around now ...these are the good ol days.

hoot

Can't we just pee into the fuel tank?

Stillman

Rather pee on the EPA...

wannadiesel

I wouldn't pee on the EPA if they were on fire.

j-fox

E= eliminate
P= petroleum
A= altogether

They are doing a good job of it!!!!

dogger

Yeah, but just think of the smell. I would if DC will have owner serviceable urea units, it so we would all have to carry an emergency 6 pack just in case the urea became dangerously low.

L8r,...dogger