From a world renowned magazine on Economics
"To meet California’s tough emission standards, carmakers have had to find ways to mop up the diesel’s unwanted NOx and trap its soot. The answer is to inject urea into a catalytic converter in the exhaust. The heat turns the atomised urea into ammonia, which, in turn, converts the hot exhaust gases into nitrogen and water. The soot is trapped by a fine mesh in a particulate filter added to the tailpipe.

Sounds complicated, but the diesel’s extra requirements cost less than you might think. For instance, Mercedes-Benz’s big new diesel sedan (the E320 Bluetec) has a sticker price of $53,025, while the petrol version of the same car costs $52,025. The Mercedes diesel gets 23 miles per gallon in the city and 32 on the highway, compared with 17 and 24 for the petrol version"

Bermuda Triangle of the Internet.

I gotta stop hanging out here early in the Morning.The News Flash(s) are
taking on a "Back to the Future" effect.

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'84 300SD sold
124.128

I checked Google and its not a hoax..its coming soon

http://www.dieselnet.com/tginfo/abstracts.html

http://www.greencarcongress.com/2005/04/mitsubishi_fuso.html

http://www.autobloggreen.com/2008/02/04/paccar-to-use-urea-injection-and-egr-to-clean-up-emissions/

http://www.naftc.wvu.edu/NAFTC%20eNews/November%2005/ureainjectionsys.html

Old news. Its been around for a few years in Europe already.

Its really an embarrassment to MB and anyone that buys a vehicle with it. It says "We can't make a clean engine so we will put a bunch of junk in the exhaust to make it look clean." Same goes with catalytic converters and particulate (soot) traps.

Why is this an embarrassment? I am not too enlightened in the field of diesel engine combustion theory, but I keep thinking thinking maybe there's an inherent design problem with these engines that never really can be overcome, and thus they require some sort of cleaning of the exhaust.

I understand that PM is created by pyrolysis, increasing the injection pressure might help that but it's already been done to a great extent as I understand. Maybe superheating the fuel before injection could produce more complete oxidation?

And for that pesky NOx problem.. it forms in high temperatures and that's a bit harder to solve..

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Tomas, Sweden
1966 Mercedes Benz 230S with OM617.912, automatic. Disk brakes from W108
1983 Mercedes Benz 300TD grey, OM617.912 and 5-speed manual
1983 Mercedes Benz 300TD blue 7-seater, OM617.912 and 5-speed manual

That is the problem. They are splitting hairs.

PM and NOx emissions are already stupidly low. The levels they are going to reduce it further in '09 only increase fuel consumption, put more wear/stress on the engine, add cost, add complexity, increase maintenance costs, reduce resale value, reduce the useful lifespan and reduce reliability. For what? Reducing emissions that produce an insignificant overall benefit to anything.


Don't you think we should be focusing on reducing our fuel/oil consumption, which would produce a major gain for everyone, instead of focusing on reducing emissions that have debatable results with such small amounts?

This is just politicians playing engineers. They are trying to force naturally inefficient and dirty internal combustion engines to become zero emission engines when it simply isn't possible or reasonably feasible to accomplish.

Engine builders are being forced to hurry up and meet some arbitrary goal that is impossible to reasonably meet in such a short period. Its causing them to spend their time developing exhaust treatment junk to make engine appear clean instead of having the freedom to develop the engine at the necessary pace.

2 cycle "screaming jimmys" wich are detroit's heat the fuel up so much that they require a fuel cooler to keep the diesel under flashpoint. i dont think it makes much diffrence other than viscosity

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Have you ever noticed that anybody driving slower than you is an idiot, and anyone going faster than you is a maniac?

As long as they would add one additional commandment for you to keep thy religion to thyself.
George Carlin (Wonder where he is now..)

1981 240d (engine donor 1983 240d) recently rebuilt engine hurray! - No more.. fought a tree and the tree won.

pearl black 1983 240d 4speed (Converted!@$$%) atleast the tranny was rebuilt.

Ok... there are two things which jump out at me in this thread... first... diesel fuel has carbon in it... thus it makes sense that soot is made when it burns....
Second.. the reference to 2 cycle Jimmy's needing a fuel cooler... of course they do... just as a gasoline engine with 21 to 1 compression ratio would need it... the fuel is in there when the air is being compressed... our diesels wait until the air is already compressed to inject the fuel... so the timing of the two getting together makes the fuel cooler moot.

Any one who wants to know who is incharge of emission regulations and law making should just type in "Who Killed the Electric Car" into google and start reading. I just saw a short movie last tuesday night and I came away very angry. There was a fellow there with an all electric Dodge Decota PU that cost him about 3 cents per mile to drive. He never had to change the oil and filter, never needed an air filter, never had to replace the rusted exhaust and didn't polute. Agreed, some of the power plants polute, but some don't. Overall, they polute much much less than all the cars on the road. We have alternatives now but big oil, our goverment, big car companies, and foreign oil all work together to keep it from happening.
Paul

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84 500 SEL (307,xxx miles)

2 cycle GMC engines DO NOT have fuel in the cylinder until the injection event which like all diesels occurs near tdc. The injectors are mechanically operated not unlike the PD Volkswagen although with a push rod and rocker arm instead of directly with the camshaft, They are direct injection without glow plugs and if not worn out start very well in cold weather as long as the fuel has not gelled,and been doing it since 1936. My $.02 Don

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Red Green "This is only temporary,Unless it works!"

97 E300D 157000 miles
87 300TD ?141k? miles

They, like the PD and CDI engines, use a fuel cooler because the injector leakoff and pump overflow fuel is very hot after being compressed to 20,000+ psi.