|This article is from Mercedes-Benz Club of America website. It overviews the future and outcomes of disel cars/vans/SUVs for each manufacturers in next two years. For those who are interested in diesel technology this might be worth of knowing...
Firstly, VW's diesel Jetta is just now arriving at dealerships. All they get right away is a single, identical, DSG-equipped Jetta sedan as an advance demo , but the engine will also appear in the Jetta wagon [this fall], the Tiguan [fall of '09], and probably the next-gen Golf/Rabbit [middle of 2010]. This engine does NOT use urea, but uses a catalyst and particulate trap that "burns" off the contents periodically. This system is not robust enough for the larger displacement diesels they will put in the Touareg, which WILL indeed use urea.
Honda is the only Asian brand that has committed to a diesel here [more on that later]. They have made a big point of NOT needing urea, and using a special catalyst that will allow 50 state sales. After an initial announcement some months ago, Honda, as is typical with them, has gone completely silent - nobody clams up like they do with new models. Consensus is that we will see their new 4 cyl diesel first in the Acura TSX, and then in the Accord. I agree, these are unlikely to be anything but model year 2010 cars. After that, who knows - maybe the CRV. The Pilot and Ridgeline are supposed to get a V6 diesel that uses the same technology - no urea.
Toyota has said absolutely zip about any diesel plans for our market - they are heavily committed to hybrids, and just aren't motivated to do anything in the US about diesel.
Subaru is rumored to have a diesel version of their boxer engine ready to go in the EU by early next year, and the USA for the 2010 model year. Emissions technology there is unknown.
BMW and Mercedes will use urea across the board. For us, that translates for the 2009 models as the GL, R, and ML, all of which will have urea tanks. The 2009 E320 diesel will only be sold in non-CA-emissions states, because there is no place to put the urea tank in the W211. When the new E gets here in 2010, it too will use urea, and this new body has been designed with the tank in mind. Audi and VW will do some with, some without. The 4 cyl diesels from the VW group seem to be able to meet both the EU and USA regs with just the catalyst and trap; their V6s will have to use urea. The indiscriminate use of the phrase "Bluetec" or "Blue" to describe some engines that require urea, and some that don't, has managed to confuse everybody - the German manufacturers have created this confusion, so the customer can be forgiven for wondering what's what.
As an aside, VW's original plan was to have the Jetta 4 cyl diesels on the road in our market months ago. During durability testing, they discovered that some of the biggest refiners in the US market [Exxon-Mobil] were producing diesel fuel that did NOT meet the ULSD standard, but was being pumped with the ULSD label [BP and Shell all tested fine, but Exxon was frequently out of spec]. This resulted in the particulate trap having to be burned/purged far more often than they had planned, and the resulting stress on the exhaust system played havoc with the durability test. They had to beef up the exhaust system to handle the possibility that 15 ppm fuel was actually closer to 50 ppm in the real world of the neighborhood pump. Once that was done, the test had to be rerun from the beginning, and Jetta diesel sedans will thus not be arriving at dealers much before the end of this month. As a further aside, VW reported their fuel quality findings to the EPA, which apparently let out a massive yawn and did nothing - always helps to have friends in the White House if you're Big Oil.
So no, urea is not universal with the Germans, but is universal with MB and BMW. And I am patiently waiting for Mercedes to get us the new-gen twin-turbo 4 cyl that was just announced, into the C for our market [and the GLK, and maybe, gasp, the E as well?]. I've been told that may happen for the 2010 model year. It will use urea - my source thinks there is room for the tank in the engine bay of the C, at least for the 4 cyl, but that hasn't been confirmed. I'm skeptical, there - I think it may wind up in the trunk, probably to the detriment of the spare tire.
Finally, for whatever reason, BMW keeps pushing back the USA intro of the 6 cyl diesel in the 3er and X5 - first it was late summer, then fall, now "December of 2008" - no indication of show-stopping problems, but no explanation, either.