2012 Passat TDI BlueTec?

Robmiezer

New member
Joined
Mar 4, 2011
Location
California
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Jetta 2010
Sure others have seen this, but the 2012 Passat TDI says it will be using BlueTec (which for the 1st three years is free from dealer). This means that it should get better milage than the current 2.0 TDI's with the post injection process (correct)? Also with this are we looking at a possiblility of using higher % biodiesel, say B50 or B100? I am not familiar with how the uric acid process (BlueTec) works, I know it is being used in Europe. But, it sounds better than the current use of extra fuel to pass United States emissions.
 

atc98002

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Joined
Nov 24, 2006
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Auburn WA
TDI
2014 Passat TDI SEL Premium (sold back), 2009 Jetta (sold back), 80 Rabbit diesel (long gone)
Sure others have seen this, but the 2012 Passat TDI says it will be using BlueTec (which for the 1st three years is free from dealer). This means that it should get better milage than the current 2.0 TDI's with the post injection process (correct)? Also with this are we looking at a possiblility of using higher % biodiesel, say B50 or B100? I am not familiar with how the uric acid process (BlueTec) works, I know it is being used in Europe. But, it sounds better than the current use of extra fuel to pass United States emissions.
I had not heard them use the BlueTec phrase, but yes it will use urea. So far their press releases are listing mileage in the same range as the Jetta TDI. Since it's larger (and likely heavier) than the Jetta, even keeping the same mileage rating shows the urea is allowing the engine tune to be more efficient. Since I've driven my daughter's Jetta on a trip and returned over 45 MPG, I expect I will do as good or better in the Passat.

I doubt this will have any effect on BD use support, however. The post combustion injection that causes all the issues is for particulate trap cleaning, and the Passat will have a trap. Since they haven't released much in the way of details for the Passat yet, I'm just making best guesses at this time.
 

Kai

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2004 Jetta TDI wagon manual; 2006 Jetta TDI sedan manual
Isn't bluetech what mercedes uses? If so, the system is no better at running biodiesel than the Jetta system is, or so I've been told.
 

kjclow

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Charlotte, NC
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2010 JSW TDI silver and black. 2017 Ram Ecodiesel dark red with brown and beige interior.
The bluetech development was a joint project between Mercedes, VW, and Chrysler. It does not necessarilly mean one type of treatment versus another. Case in point, both the dpf and urea treatment came out of the joint project. However, BlueTec is the marketing phrase that Mercedes is using for their new diesels.
 

Robmiezer

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Mar 4, 2011
Location
California
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Jetta 2010
Thanks for the info. I was using BlueTec as a general term, I suppose I should say that it is using urea. But as I see it, the urea is injected from a different tank in the trunk. From what I have read, most problems in using over 20% biodesel is that it does not vaporize during the post injection process. This causes it to stick to the walls and get mixed into the engine oil on the next cycle. After time it dilutes the oil and this is BAD. So, if the urea is injected from a different line and there is no second injection of fuel, I am guessing you would not have to worry about the oil dilution using higher than %20 biodiesel. As I said I am not familiar with the urea process and many others are. But, to me it sounds like B100 should run with no problems of oil dilution. There may be other problems, but I understand that is the main problem, again please correct me :)
 

Kai

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Apr 15, 2004
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2004 Jetta TDI wagon manual; 2006 Jetta TDI sedan manual
Re: Mercedes bluetech: I heard someone on Maui who runs biodiesel ordered several Mercedes bluetech cars, but then cancelled the order when he learned that these cars will NOT run biodiesel in B100 or any significant blend. I got the same story from the Mercedes dealer when I asked about it. But I never explored it deeply after learning the above.
 

atc98002

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Joined
Nov 24, 2006
Location
Auburn WA
TDI
2014 Passat TDI SEL Premium (sold back), 2009 Jetta (sold back), 80 Rabbit diesel (long gone)
Thanks for the info. I was using BlueTec as a general term, I suppose I should say that it is using urea. But as I see it, the urea is injected from a different tank in the trunk. From what I have read, most problems in using over 20% biodesel is that it does not vaporize during the post injection process. This causes it to stick to the walls and get mixed into the engine oil on the next cycle. After time it dilutes the oil and this is BAD. So, if the urea is injected from a different line and there is no second injection of fuel, I am guessing you would not have to worry about the oil dilution using higher than %20 biodiesel. As I said I am not familiar with the urea process and many others are. But, to me it sounds like B100 should run with no problems of oil dilution. There may be other problems, but I understand that is the main problem, again please correct me :)
Rob, while the urea is injected from a separate line, it has nothing to do with the cleaning of the particulate filter. That is what the post injection is for (only happens during a computer controlled cleaning event, not continuously), and these post injections will still occur, even on urea equipped engines.

Urea injection is for control of nitrous oxides, and replaces a different piece of emission control equipment. Since it can control the NOx so well, the engine can be tuned more favorably, and is why I believe the new Passat will have a MPG rating equal to or slightly higher than the Jetta.
 

atc98002

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Joined
Nov 24, 2006
Location
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TDI
2014 Passat TDI SEL Premium (sold back), 2009 Jetta (sold back), 80 Rabbit diesel (long gone)
Re: Mercedes bluetech: I heard someone on Maui who runs biodiesel ordered several Mercedes bluetech cars, but then cancelled the order when he learned that these cars will NOT run biodiesel in B100 or any significant blend. I got the same story from the Mercedes dealer when I asked about it. But I never explored it deeply after learning the above.
Mercedes has the same B5 restriction as VW, but it isn't real easy to find on the web site. BMW's web site doesn't mention it at all, but I saw an owners manual for the 335d and it also states B5 max.

I think it's all a matter of CYA by their legal departments. Until we have solid standards in place, I doubt we will see passenger cars with higher levels of BioD in use for some time. With some states mandating higher levels of BioD in their pump diesel, we might even see some states no longer carrying and diesel cars. That makes me sad :(
 

Robmiezer

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Mar 4, 2011
Location
California
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Jetta 2010
Rob, while the urea is injected from a separate line, it has nothing to do with the cleaning of the particulate filter. That is what the post injection is for (only happens during a computer controlled cleaning event, not continuously), and these post injections will still occur, even on urea equipped engines.

Urea injection is for control of nitrous oxides, and replaces a different piece of emission control equipment. Since it can control the NOx so well, the engine can be tuned more favorably, and is why I believe the new Passat will have a MPG rating equal to or slightly higher than the Jetta.

Thank you for the explaination. I did not realize the urea was for NOx. I thought it was being used to clean the particulate filter (though it was a chemical cleaning instead of burn). So, the post injection is still an issue and B20 should be the very highest used, unless you want oil problems.
 
Joined
Mar 2, 2011
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Europe/US
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Jetta
For clarity

On the Jetta which has a DPF plus LNT (lean Nox Trap), there are two different sets of post-injection event. One for DPF, one for LNT.

1. DPF
The DPF injection, triggered by DPF soot load or by mileage, will happen once every 300 miles or so, but lasts quite a while.

2. LNT
For the Jetta LNT, LNT regeneration occurs every time the NOx absorbed is full. It involves changing the air fuel lambda ration to one, which includes temperature support upto 450 C. Combination as follows - The air is choked off with a throttle, extra fuel is need for the pumping loss, and there is post injection for temperature support. This will happen for 5 seconds once every 10 minutes or so.

SCR in the passat will eliminate 2, but 1 will remain.
 

atc98002

Veteran Member
Joined
Nov 24, 2006
Location
Auburn WA
TDI
2014 Passat TDI SEL Premium (sold back), 2009 Jetta (sold back), 80 Rabbit diesel (long gone)
On the Jetta which has a DPF plus LNT (lean Nox Trap), there are two different sets of post-injection event. One for DPF, one for LNT.

1. DPF
The DPF injection, triggered by DPF soot load or by mileage, will happen once every 300 miles or so, but lasts quite a while.

2. LNT
For the Jetta LNT, LNT regeneration occurs every time the NOx absorbed is full. It involves changing the air fuel lambda ration to one, which includes temperature support upto 450 C. Combination as follows - The air is choked off with a throttle, extra fuel is need for the pumping loss, and there is post injection for temperature support. This will happen for 5 seconds once every 10 minutes or so.

SCR in the passat will eliminate 2, but 1 will remain.
Excellent explanation. I didn't realize there was any post injection other than the DPF. Good to know at least some of it is eliminated. Thanks! :D
 
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