VW To Debut New Clean Diesel Engine in 2014

There's a place for diesels and they will help save fuel, but the bit that hit me was the following;

It will use a complex exhaust gas recirculation system (with a high pressure EGR and a cooled low-pressure EGR)

Good luck with that!

 

I have no idea if there will be reliability problems, but cooled low pressure egr makes perfect sense for efficiency, and you need the high pressure one for leaner burns.


VW Confirms New TDI Clean Diesel Engine Details For U.S.

It sounds like vw has been able to bring the cost of pollution reduction down, while bringing power and efficiency up.

 

This engine has been talked about for a while. For example, the Diesel Driver discussed it a bit last month in this article:
Diesel Car Preview for 2014-15 – The Diesel Driver - The Joy of Diesel Driving

eheath is right. VW Auto Group is not resting on its laurels, as far as North American diesels go. You will see on page 1 of the Diesel Car Preview that Audi is bringing a number of diesels new to the US next year; and on page 5 you will see that VW is too. VW wants to up its total percentage of diesels sold in the US from 20 to 30 percent--in the article this appears to apply only to the VW brand and not its other brands sold here--Audi and Porsche.

 

If they have a diesel that improves emissions, while retaining the high fuel economy, without SCR,VW will get many lookers at least.

 

Technology improves? I'm shocked:


Bob Wilson

 

Mazda is the company that built a diesel that looks like it can pass emissions without SCR the skyactiv-d.

The description of this engine makes it sound like they have reduced the price of emissions parts, but we won't know until diesel pricing comes out. The new EGR system may cost more, while the SCR and dpf sound like it will cost less.

 

The current TDI already uses both high and low pressure EGR systems. I think that may be a feature only in North America though, perhaps VW is expanding its usage to worldwide.

 

Europe needs euro 6 in 2015. It looks like this is the new improvements on the US/Euro 6 engine. I did not know the american model already had this feature, so needing to add it to all the european diesels should drop the cost. The main change for americans then will be 10 more hp, and a more efficient engine.

I don't know about vw, but bmw offers a euro 6 option on many diesels for more money. Customers in europe can choose to pay more, to be cleaner, before it is required by the governments.

 

The Jetta TDI, at least previous years, didn't use SCR. Its just that the larger Passat TDI with the same engine and SCR is onyt 1, maybe 2, mpg shy of the Jetta. That seems to be the main hurdle of non-SCR emission control. Doing it without losing diesel's fuel economy advantage.

Honda had considered bringing over a diesel Accord to replace the original hybrid one. It met T2B5 emissions without SCR. A plus at a time when urea injection was looked down upon by most consumers. It was cancelled for the Accord, and shifted to the TSX. I remember hearing the cost to fuel savings benefit of the Accord being to high back then. Honda cites economical reasons for delaying the Acura. This was 5 to 7 years ago, so they might be rethinking with the new Cruze diesel, and Mazda's plans with it.

Honda to launch clean diesel in the U.S. within three years. - Car News - Car and Driver
Acura diesel on hold because of business conditions, not tech issues

 

I may have this wrong, but I thought the Jetta tdi used scr but did not require urea, it used a process with the diesel fuel to remove the nitrogen. I thought he mazda skyactiv actually produced low enough NOx that SCR was not needed. Both systems are likely less efficient than on that uses urea in the scr process. IIRC correctly bmw is making the most efficient small diesel, and it requires urea. The mazda trick is to be lower cost. I think this new vw tdi ice will lower the cost from the current one.

 

"NOx adsorbers are experimental technology as of early 2006, and thus extremely expensive. Whether or not this technology will be successfully commercialized is open to question—only time will tell. A NOx trap is used on the Volkswagen Jetta Clean TDI and the Volkswagen Tiguan concepts. Both are projected to be introduced into the American market by 2008.[2] They were to be marketed as part of the BlueTec program from Audi, Daimler-Chrysler, and Volkswagen."
NOx adsorber - Wikipedia, the free encyclopedia

It does use diesel to regenerate the adsorber.

For completeness: Selective catalytic reduction - Wikipedia, the free encyclopedia

I have heard of experimental systems that had a catalyst that would convert diesel into urea for the SCR one. Except for not needing another tank for urea, I don't see what the benefit would be.

The Mazda diesel does produce low enough NOx it seems to at least only need a 3 way cat convertor. At least in other markets. It seems our diesel is like our gasoline compared to those markets: crap.
"The difficulty, and frankly, the delay for US sales relates to the quality of the fuel. “The cetane number is low, which means the fuel itself has less ability to auto-ignite,” Ishino said. The challenge for Mazda is to ensure the engine starts up without difficulty and still controls soot and NOx in such conditions, because the diesel formulation in the US will not change for the sake of accommodating a clever engine."
- BBC - Autos - Mazda prepares US diesel invasion

I haven't heard of an actual release date for the diesel Mazda6 yet. Hopefully they can get their emission controls to work as intended. Even if they have to resort to a NOx trap because of our diesel, it shouldn't hurt fuel economy much for the Skyactiv-D. Sounds like the extra NOx production is during cold startup. So regen cycles for the adsorber will be few.

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