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Volkswagen Testing Tier 2 Bin 5 “Clean TDI”, Slated for Production in 2008

“Clean TDI” Tier 2 Bin 5 VW.

Volkswagen is testing a Tier 2 Bin 5 compliant “Clean TDI” diesel powertrain—a new 2.0-liter diesel and a lean NOx trap—in a Jetta. Volkswagen says its “Clean TDI” vehicles will go into production in the US in 2008.

Volkswagen, which is a member of the BLUETEC initiative announced in November 2006, has also announced a concept “Clean TDI” Tiguan SUV. (Earlier post.)

VW plans to use two types of emissions control systems. Click to enlarge.

Volkswagen has developed two new systems connected to the oxidation catalytic converter and the particle filter in the exhaust system to meet the stringent NOx reduction requirements of the Tier 2 Bin 5 / CA LEV II standard (the threshold for sales in all 50 states of the US).

For car models of the Passat class and smaller, Volkswagen is testing its new lean NOx trap catalytic converter (discontinuous). At λ of greater than 1, NOx is captured and stored; at λ less than 1, NOx is released and reduced. Ultra low-sulfur fuel is a necessity, and fuel consumption will increase as a result of catalytic converter regeneration.

Larger and heavier models feature urea Selective Catalytic Reduction (SCR) catalytic converter (continuous) with the use of an aqueous solution such as AdBlue, transported in an additional tank made from stainless steel or plastic.

Urea comprises 32.5% of this solution, which is continuously injected into the exhaust system in front of the SCR catalytic converter using a metering valve. The dosage is made according to the gas emission stream.

The urea solution is finely atomized by a grille and is converted in hot exhaust gas into ammonia before it reaches the catalytic converter. The ammonia then reacts with the nitrogen oxide in the catalytic converter and separates it into nitrogen and water.

Volkswagen intends to install the additional tank so that the car can be driven without maintenance between services. For the US, the complete system must be fully functional for at least 150,000 miles.

BLUETEC is a joint project between Volkswagen, Audi and DaimlerChrysler, and is intended to establish the diesel engine further in the American car market. The manufacturers are promoting the diesel engine as a low-consumption alternative for future car use. Each of the manufacturers involved in the BLUETEC joint project is working on individual technical solutions for stringent exhaust gas emission standards and plans to market these independently.

Volkswagen has sold more than 800,000 diesel cars in the US to date.




Someone at TDIClub sighted a prototype of this car last Sept:

At the time, VW was showing a Jetta with a 6 speed manual, and at the time they were estimating fuel economy of 43 city, 60 highway.


Great - as long as it does not cost too much.
You would like to see this on all diesels, but for te cost.

fyi CO2

Eric, where can this vehicle's mpg data verified?
I see the 2006 Jetta TDI model was only EPA 35/42 mpg, and that model was not tier 2, bin 5 compliant.


You currently cannot see the data verified. The person who saw the car in Boston asked the engineers who were showing it, and that is what he was told, so for the moment it is all unofficial.

I will say this though - my 2002 Jetta TDI had an EPA highway of 49mpg. It now has about 83K miles on it, and in the most recent tank I got 48.3 in mostly highway driving.

Starting with the 2004 model they went to unit-injectors and the fuel economy suffered a bit. VW will now abandon this in favor of common-rail in the 2008 models.


Tier2 bin5 without additives (passat size and smaller) makes diesel a reasonable alternative to me.

EPA was 49 for your 2002 Jetta on the highway and you achieved 48.3...but that doesn't say much because the EPA for my 99 Mitsubishi Mirage was 35mpg highway and I routinely achieve 40mpg with highway driving and I have 100,000 miles on it.


where can this vehicle's mpg data verified?

There are no official numbers for it, and the 43/60 might be Imperial, not US. And that's for a 6 sp common rail, not a 5 sp unit injector.

I see the 2006 Jetta TDI model was only EPA 35/42 mpg, and that model was not tier 2, bin 5 compliant.

That said, while you can always beat EPA with careful driving in any car, apparently it's particularly easy to beat EPA with these cars. A recent Oak Ridge National Laboratory survey showed that diesel drivers on average got 4% better than EPA, regular gasoline drivers 1.3% worse, and hybrid drivers 8% worse. The methodology is informal but in line with anecdotal evidence. FWIW my 06 Jetta gets about 43 mpg on biodiesel (about 2/3 city, 1/3 highway). On regular fossil diesel that would be more like 45-46.

Rafael Seidl

Mahonj -

Current VW Jetta Comfortline in Germany:
1.4L TSI 125kW 7.3L/100km ROZ 98 MRSP 24.570EUR
2.0L TDi DPF 125kW 5.9L/100km diesel MRSP 27.000EUR

Note that this particularly efficient gasoline engine option features dual chargers and direct injection. I'm not sure if VW has announced plans to introduce it to the US market.

The diesel options for the German model satisfy Euro 4 emissions but not Tier 2 Bin 5, i.e. they do not include the NOx trap. The MRSPs given already include 19% sales tax. 1 EUR = approx. $1.25.

The fuel economy data is based on the NEDC test rather than its US counterpart, but as a first approximation I'll just convert the numbers and assume usage of 12,000 miles/year:

7.3L/100km = 32MPG US => 375ga/yr @ $2.779 = $1042/yr
5.9L/100km = 40MPG US => 300ga/yr @ $2.705 = $812/yr

Fuel prices are averages over 2006 across the US and may differ substantially in your area:

In other words, if these current German gasoline and diesel variant were available in the US today, the fuel savings of the diesel option would amount to approx. $230 per year, subject to the approximation inherent in standardized drive cycles.

The new "clean TDi" for the US market will have to do better to justify the cost premium of the diesel engine incl. DPF and NOx trap. If Eric's assertion of 43/60 MPG US (51 avg) turns out to apply to an engine option in the 125kW category, annual savings at the pump would amount to approx. $400. That would probably permit the amortization of the clean diesel premium in well under a decade.

Note, however, that the above calculation is speculative and does not account for non-fuel costs such as VLFs, insurance rates and especially, asset depreciation rates which may be substantially different for the diesel variant (in either direction, btw). For the next few years at least, diesels will still account for just a few percent of the total LDV market, so finding a used vehicle or a buyer for one will be harder than for the gasoline variant.


I have an 05 TDI with unit-injectors. I get 46mpg in combined driving and have done 52mpg on a roadtrip. I do run 5 ounces of PS per tank. I got 43mpg in combined driving using as much as 70% Bio all summer.

fyi CO2

"A recent Oak Ridge National Laboratory survey showed that diesel drivers on average got 4% better than EPA, regular gasoline drivers 1.3% worse, and hybrid drivers 8% worse."

regular gasoline drivers only 1.3% worse ???
do you have a link to the details of this survey?

While I don't think a Univ. working for the DOE is under any outside influence this information contradicts the EPA statement that their ratings may not = real-world mpg, they are highly consistent from one test to the next and one vehicle to the next.


regular gasoline drivers only 1.3% worse ???
do you have a link to the details of this survey?

The results are reported in the
Technical Support Document
for the new EPA regs. I do not have methodology details. Personally I suspect the ORNL survey is optimistic: it's self reporting, is not rigorous about use of repeatable measurements, road conditions, whether MPG numbers are calculated or taken from an on-board computer, etc, and may well favor those who take fuel economy seriously.

mike Belverud

I have a 2003 jetta TDI and have never had less than 45 MPG. The best I've had was just over 55 on a long trip. I've been using bio-d for a couple of years and last year I made the fuel myself with excellent results. Does anyone know if the new common rail engine will be warrentied for biodiesel?


"While I don't think a Univ. working for the DOE is under any outside influence..."

Just the same politicians that appoint the DOE bureaucrats, who are also the same politicians that propose 30 year biofuel standards.

Jeff Conforti

I have a 2006 Jetta TDI and can get 32 to 42 mpg city and 43 to 57 mpg on the highway depending on the terrain and how fast I drive. at 65 mph on a flat highway 57 mpg is easy.

It's all in how you drive. Also, my 2007 ML320 CDI can get 31 mpg highway at 65 on a flat road. In town it can be 18 mpg if I use all that low end torque but it usually is 21 mpg because I don't drive like a maniac.


bill meadows

does anyone make a diesel hybrid, if not why not?

Lance Man

Regarding diesel hybrids there is currently an even better alternative using free vegetable oil. Check out: or

Also watch the movie - Who Killed the Electric Car - Fascinating

Available at most libraries or your local video store.

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