TDI NOx emissions compared to average car

Tankbuster

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Tennessee
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How about a TDI vs Lightning or fertilizer

How about NOx from a single lightning strike or fertilizer that farmers use. Really no comparison with the tiny amount from TDI's compared to these, but VW is an easy target for the EPA Mafia.
 

wxman

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East TN, USA
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Actually, there have been studies that have qualified NOx emissions from lightning strikes and agricultural land.

For lightning, NASA estimates from satellite data that each lightning strike produces an average of 715 (+215) moles of NOx. Assuming all NOx is NO, 715 moles NOx X 30 g/mole = 21,450 grams average NOx produced per lightning strike.

For agriculture land, the "Southern Oxidant Study" conducted in the mid-1990s estimated that biogenic NOx from land accounted for over 17% of the total NOx in Middle Tennessee during the hottest time of the day/year. The average ambient NO2 for the entire year was 55 ppb. 0.17 X 55 ppb = 9.35 ppb from biogenic agricultural sources, assuming the 55 ppb NO2 is representative of the NO2 concentration in mid-July.
 

n1das

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Actually, there have been studies that have qualified NOx emissions from lightning strikes and agricultural land.

For lightning, NASA estimates from satellite data that each lightning strike produces an average of 715 (+215) moles of NOx. Assuming all NOx is NO, 715 moles NOx X 30 g/mole = 21,450 grams average NOx produced per lightning strike.

For agriculture land, the "Southern Oxidant Study" conducted in the mid-1990s estimated that biogenic NOx from land accounted for over 17% of the total NOx in Middle Tennessee during the hottest time of the day/year. The average ambient NO2 for the entire year was 55 ppb. 0.17 X 55 ppb = 9.35 ppb from biogenic agricultural sources, assuming the 55 ppb NO2 is representative of the NO2 concentration in mid-July.
How many Gen1 CR TDIs would 21450 grams of NOx per lightning strike represent, assuming Gen1 TDIs are always emitting at the worst case level found in the ICCT/WVU study? The media loves to keep running with that 40x number and assumes that it occurs ALL the time while we know it only occurs under a very specific set of worst case driving conditions.
 

n1das

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The fleet average (often call "max emission" or "legal limit") is 0.07 g/mi. This is the same as Tier2Bin5 full lifespan (10 year 120K miles) limit. Using zero prefixed decimal places drives me crazy so I will write everything in mg/mi. The vehicles in your list range from 13 mg/mi to 20 mg/mi. The max fleet average is 70 mg/mi (Tier2Bin5) and the absolute limit per vehicle is 200 mg/mi (Tier2Bin8). In the WVU study the Jetta was tested on 8 road tests involving urban, rural, and hwy conditions. The emissions ranged from 614 mg/mi to 1480 mg/mi. Across all 8 road tests the mileage weighted average would be 1084 mg/mi.

Understand however that only three vehicles were tested in the WVU study, a 2012 Jetta, a 2013 Passat, and a 2012 BMW X5. The WVU study blew the whistle and subsequently the EPA widened the investigation to in include your Golf but we don't know what the emissions of the Golf are. The EPA hasn't released the details of their findings (and they won't as this is an ongoing investigation).

Still you shouldn't really compare diesel vehicles to gas vehicles and look at only NOx. Gas vehicles generally don't have any significant NOx emissions. They tend to operate at a lower temp which means less NOx production and then they have the highly efficient 3-way cat (>99% reduction in NOx). On the other hand gas vehicles tend to have more CO and more unburned hydrocarbons (NMOG). Diesel vehicles tend to have more NOx and more PM (particulate). So for a more apples to apples comparison I would compare it to other diesel vehicles.

Lastly CO2 is directly related to fuel consumption. When comparing between two fuels keep in mind that 1 gallon of diesel has 13% more carbon. So 40 mpg gas ~= 45 mpg diesel in terms of CO2 output. As a side note the EPA mpg rating is calculated based on the weight of the CO2 which is emitted. If you run a vehicle and capture the exhaust and the CO2 in the exhaust weighs 10.15 kg then you have burned 1 gallon of diesel. Yes technically fuel isn't completely burned (NMOG, particulate, CO, HCHO, etc) so one should really measure and weigh all those and compute what portion came from the atmosphere. As a practical matter those non-CO2 outputs are a rounding error <0.1%. So the weight of the carbon in CO2 = weight of carbon in the fuel.
Great summary!

I will gladly take high NOx from an emissions cheating TDI any day and have significantly LOWER emissions in all of the other categories (GHG, HC, VOC, PM) compared to an equivalent gasser. "Pick your poison" applies.

Have fun! :)
 

wxman

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How many Gen1 CR TDIs would 21450 grams of NOx per lightning strike represent, assuming Gen1 TDIs are always emitting at the worst case level found in the ICCT/WVU study? The media loves to keep running with that 40x number and assumes that it occurs ALL the time while we know it only occurs under a very specific set of worst case driving conditions.
The Jetta TDI tested in the ICCT/WVU study produced 1.505 g/km or about 2.42 g/mile in the "uphill/downhill" test (worst-case). That would mean that a TDI producing that emission rate would have to go nearly 10,000 miles to equal the NOx produced by one "average" lightning stroke.

I've personally seen one diurnal air mass ("pulse") thunderstorm produce over 1,000 cloud-to-ground lightning strikes over its life span (averages about 45 minutes), so a lot of NOx is potentially generated in just ordinary pulse thunderstorms.
 

patbob

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Ok, but there aren't 500,000 thunderstorms going on at once. There aren't even 500,000 thunderstorms in the USA in a year , but there are 500,000 TDIs, each driving at least 10,000 miles in a year.

Like others said, pick your poison.
 

wxman

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Ok, but there aren't 500,000 thunderstorms going on at once. There aren't even 500,000 thunderstorms in the USA in a year , but there are 500,000 TDIs, each driving at least 10,000 miles in a year.

Like others said, pick your poison.
No, but there are FAR more than 500,000 lightning strikes in the U.S. per year. Estimate is about 20 million cloud-to-ground lightning strikes per year (about 60 million strikes of all kind, including cloud-to-cloud and intra-cloud strikes).

That would equate to over 400,000,000,000 grams of NOx from CG lightning strikes if the NASA estimates are correct.

I'm not defending the TDI emissions issue, just providing estimated amounts of NOx from natural sources.
 

\/\/0J0

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Sadly, none anymore
Ok, but there aren't 500,000 thunderstorms going on at once. There aren't even 500,000 thunderstorms in the USA in a year , but there are 500,000 TDIs, each driving at least 10,000 miles in a year.

Like others said, pick your poison.
I don't think you read the above comment where it indicated that each STRIKE, not storm, equals 10,000 miles of the worst case scenario of driving. So if the storm mentioned above (having 1k lightning strikes) counts as a typical storm, then only 500 storms would need to spawn, annually, to equal all the NOx emissions from "bad" vw diesels that would occur from driving said vehicles uphill for 10,000 miles per year. How many uphill miles do you drive per year?

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GoFaster

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Bear in mind that NOx emitted higher in the atmosphere and in scattered locations and surrounded by raindrops, fog/cloud droplets and moisture (NOx is absorbed by water, and rain rinses it out of the air pretty quickly) is a different ball game from NOx emitted together with hydrocarbons at street level in the Los Angeles basin on a sunny day in an urban area with millions of people in it.
 

turbovan+tdi

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2003 TDI 2.0L ALH, auto, silver wagon, lowered, Colt stage 2 cam, ported head,205 injectors, 1756 turbo, Malone 2.0, 3" exhaust, 18" BBS RC GLI rims. 2004 blue GSW TDI, 5 speed, lowered, GLI BBS wheels painted black, Malone stage 2, Aerotur
Really? The so called "medical people" have such a VAST area of expertise in the field of combustion engineering now don't they? How many of these "experts" realize that when you have a stoichiometric fuel/air mix for optimum efficiency utilizing an "air" source that is 78% Nitrogen and 21% oxygen that there WILL BE NOx emissions? How many of these "experts" realize that for every home in the USA that burns #2 heating oil as a fuel source that there is MORE NOx being emitted by these sources than a VW TDI engine? MORE NOx emissions in large industrial burners for whatever purpose fueled by natural gas as well. I know this for FACT because I "tuned" these devices for 30 years. Some as large as 700,000,000 BTUs with 15 psi of gas pressure that the burner manifold. Even with the "newest" exhaust gas treatment systems on over the road trucks the TDI is cleaner. Ever been behind one of those gasoline fueled vehicles belching the "rotten eggs"? What about them? As for the CO2 "concerns"? That "science" if you want to call it that is being debunked on a regular basis. By people with more expertise than some fellow branding those on this forum as "know nothings".
Maybe CARB should do a "study" on how much NOx a certain high powered "political figure" has emitted into the atmosphere when
4 General Electric CF6-80C2B1 turbofans
were delivering him, family/friends + their "entourage" to the "vacation spots"? Just sayin'?:rolleyes:
Well said. :cool:
 

Tankbuster

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Location
Tennessee
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2011 Jetta TDI
Lots of great info, I'm not sure why I have such good health living in middle Tennessee with these almost daily thunderstorms surrounded by thousands of acres of farmers using fertilizer and driving a TDI. Thank you EPA Mafia.
 

flee

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Location
Chatsworth, CA
TDI
2002 Jetta GLS wagon
Lots of great info, I'm not sure why I have such good health living in middle Tennessee with these almost daily thunderstorms surrounded by thousands of acres of farmers using fertilizer and driving a TDI. Thank you EPA Mafia.
You would see the need for these regulations if you lived in an urban environment like
most of the US population. It is easier to prevent the pollution that to clean up later.
 

nwdiver

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Lots of great info, I'm not sure why I have such good health living in middle Tennessee with these almost daily thunderstorms surrounded by thousands of acres of farmers using fertilizer and driving a TDI. Thank you EPA Mafia.
Lightning and farms are diffuse rural sources. As has been mention and mention and mentioned ad nauseam... the threat is urban street level sources... aka tailpipes. I do thank the EPA... I no longer have asthma attacks when I walk downtown now that there are limits on NOx emissions.

How's this... lighting and farms is like pissing in the toilet... your TDI on main street is like pissing in the living room... see the difference? To be fair you TDI in rural Tennessee is no worse than the farms and lightning. Perhaps we should just ban ICE from cities and stop regulating the tailpipe.
 
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\/\/0J0

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Sadly, none anymore
Lightning and farms are diffuse rural sources. As has been mention and mention and mentioned ad nauseam... the threat is urban street level sources... aka tailpipes. I do thank the EPA... I no longer have asthma attacks when I walk downtown now that there are limits on NOx emissions.

How's this... lighting and farms is like pissing in the toilet... your TDI on main street is like pissing in the living room... see the difference? To be fair you TDI in rural Tennessee is no worse than the farms and lightning. Perhaps we should just ban ICE from cities and stop regulating the tailpipe.
Jello Biafra proposed a ban on all cars within city limits as part of his campaign platform when he ran for mayor of San Francisco. He also proposed that folks in the business district should be required to wear clown suits between 9a and 5p. He only lost by something like 17 percent

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nwdiver

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Jello Biafra proposed a ban on all cars within city limits as part of his campaign platform when he ran for mayor of San Francisco.
It would be silly to ban all cars. Not all cars are the problem...
 

turbovan+tdi

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Jello Biafra proposed a ban on all cars within city limits as part of his campaign platform when he ran for mayor of San Francisco. He also proposed that folks in the business district should be required to wear clown suits between 9a and 5p. He only lost by something like 17 percent

sent from my mobile look at device
Damn. :eek:
 

tikal

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Hidden cost(s) of transportation energy?

If we agree to include the 'Vehicle Manufacturing' health costs to the equation of the emissions impact from our cars then we ought to consider the National Academy of Sciences report titled: "Hidden Cost of Energy: Unpriced Consequences of Energy Production and Use." (2009),http://www.nap.edu/openbook.php?record_id=12794. The chart below is courtesy of wxman and is similar to the one you can find in the above report in Figure 3-7(a), Page 212 (of 506):


In my view, after you look at the graph and what's the science behind it, neither modern light-duty diesel cars are as 'grey' as they are portrayed in society nor electrical vehicles are as 'green' ('zero emissions') as we might believe they are. The truth of the matter is complex and somewhere in between (again in my humble opinion).

Should we mainly be concerned with 'local tailpipe' emissions or with global overall emissions impact on our planet?
 

flee

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Very interesting. A significant impact is the ongoing consumables that ICEs use
that are largely eliminated by electric vehicles.
 

Tankbuster

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Location
Tennessee
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2011 Jetta TDI
Very interesting graph about the real hidden costs on transportation .

I remember reading a story years ago about how great people thought it was in the early 1900's when cars first starting replacing horses in the big city's. No more unsightly horse manure filling the city streets with the horrible smell and disease carry flies. Wonder what will we be complaining about in next hundred years?
 

Treg-tdi

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Calgary
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Touareg (2012)
Seen a lot pertaining to the small tdi emissions, but little or nothing about the bigger engine from VW.
How about the 3.0 tdi in the Touareg and Audi Q7?
How do they compare to other diesel vehicles?
 

Perfectreign

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Los Angeles
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Should we mainly be concerned with 'local tailpipe' emissions or with global overall emissions impact on our planet?
I've been stating this for years. My 16-year-old vehicle produces less overall pollution than a 2016 model vehicle with a massive chemical battery.
 

wxman

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Hamman

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No TDI's, but an '84 Rabbit diesel
Emissions from original golf/rabbit diesel

I watch the Netflix "expose'" on the vw diesel gate last night and got to thinking about what another poster asked earlier in this old thread. What level of NOx did our older diesels emit? I have an '84 Rabbit with no emission controls, so out of the box, I found that according to this article (EPA), it was putting out less than the CR TDI's involved in the scandal. Correct me if I'm wrong, but if the offending cars were putting out well over 1 to 2 grams/mile, then my old one might be cleaner from that standpoint. Here is the URL link;
https://nepis.epa.gov/Exe/ZyNET.exe...ackDesc=Results page&MaximumPages=1&ZyEntry=1
 

patbob

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was a 2013 Jetta TDI
I looked up my '83 Mercedes diesel.. i can't recall the exact value, but it was way up there (1g/mi?). At its worst, the TDi was still under that.

Where I live, driving the Mercedes would be OK, but not the TDi.
 
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Lightflyer1

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From post #3:

In the WVU study the Jetta was tested on 8 road tests involving urban, rural, and hwy conditions. The emissions ranged from 614 mg/mi to 1480 mg/mi. Across all 8 road tests the mileage weighted average would be 1084 mg/mi.
 

IDoSeaDoo

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Raleigh, NC
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Anyone know why only the 2015's could be 'fixed'? I have a 2011 and wonder how the 2015 differs aside from the facelift. Mine is a rescue (salvage title), so it's exempt from any fixes, but I wish it wasn't such a polluter. I hear people that got the fix are claiming better mpg numbers. I wonder if the car can still pull as much, as I regularly tow a small boat and jet skis.
 

Lightflyer1

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I may be wrong but I didn't think any running licensed car was exempt from the fix, only the compensation. Don't be fooled by all the bad press either. Even as they were stock they were very clean except in one category and that was only sometimes. Some report slightly better some slightly worse. I would think whatever you did before is still possible.
 

wxman

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Anyone know why only the 2015's could be 'fixed'? I have a 2011 and wonder how the 2015 differs aside from the facelift....
The 2015s had much lower NOx emissions than the earlier generations even before the "fix", according to CARB:


 

TDIMeister

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Canada
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TDI
Anyone know why only the 2015's could be 'fixed'? I have a 2011 and wonder how the 2015 differs aside from the facelift. Mine is a rescue (salvage title), so it's exempt from any fixes, but I wish it wasn't such a polluter. I hear people that got the fix are claiming better mpg numbers. I wonder if the car can still pull as much, as I regularly tow a small boat and jet skis.
Pre-2015 common rail TDIs used a different NOx aftertreatment strategy (Lean NOx Trap - LNT - vs Selective Catalytic Reduction - SCR). The CR Passat has used SCR since 2012. The main difference between the two methods that are observable by the end user is the reductant used, Diesel fuel vs DEF, respectively. Theoretically, there should be little difference in the conversion efficiency from NOx to N2 between the two approaches, but the expense of the amount of reductant used. VW cheated because getting the TDI to pass emission limits for NOx would result in an unacceptable compromise in fuel economy - something they discovered either too late in the development cycle to change, or due to hubris on the part of management/engineering, or pressure to use the cheaper and less inconvenient LNT solution. Many have sought to explain the reasons, and an overbearing management and corporate culture have been implicated, but we can only state what we know for sure.

Edit: In short, an LNT-equipped TDI could ostensibly meet regulations, as the Gen-1 post-fix result in the above post shows. The Gen-1 fixes retain an LNT but include a brand new catalyst with an improved formulation, as well as other changes. My understanding of the consent decree is that the fixed Gen-1 TDIs will still not meet the T2B5 NOx limit of 0.07 g/mile - rather understandable considering many of the cars will have substantial miles put on them already, and many exceeding the 120k miles within which the limit applies; if it could be made to do so, the fuel economy would be impacted so much that it would be pointless. VW must have come to know this during the development back in 2007-ish and the technology available at that time, but instead of making the fix right in the place (i.e. go to SCR) decided to cheat and hide its activities because too much was already invested and riding in LNT.

SCR-equipped TDIs are fixed by removing the defeat programming and calibration changes that include an increased amount of DEF consumed but not so much so that it is significantly noticed over the refill intervals of several thousand miles.
 
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