Didn't see this coming - EPA shift

wxman

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If you look back at the history of emissions in diesel engines in Europe vs the united states, it's fairly clear why they never gained major acceptance in the USA. They (diesel engines) were often given preferable emission laws that were more lax then what gas engines had to meet. It wasn't till the late 90's (ish) that the eu started getting serious about emissions in diesels. They never really had a large market share in the USA because our standards were a lot tighter, and the perception of dirty, noisy diesels was never really put to rest.
Actually a fairly good video on the topic.
The "hair on fire" presentation in that video after ~22:00 minutes regarding the air quality in Europe is overly dramatic, IMHO. The ambient NO2 levels in 2016 were above the European ambient air quality standards in only 7% of the monitoring locations. Even then, Europe decided to adopt the WHO air quality guidance (AQG) for NO2, but *NOT* for any of the other criteria pollutants. The ambient NO2 AAQS and WHO AQG are set at 40 µg/m3, which is more than twice as strict as the U.S. NAAQS (53 ppb or ~103 µg/m3). No European monitor would have exceed the U.S. NO2 NAAQS, according to that report.

Regarding the assertion that "most" PM comes from diesel engines, a 2015 study in London (Bohnenstengel et al., “Meteorology, Air Quality, and Health in London.” Bulletin of the American Meteorological Society, May 2015) concludes that most of the black carbon (BC) captured at monitoring sites comes from residential wood burning. Even then, the average BC concentration at the most urban location tested averaged 1.9 µg m−3 out of total PM10 of 18.59 µg m−3, only about 10%. PM from diesel engines is about 75% BC according to an EPA study.

In France, two-stroke scooters and wood burning were the biggest contributors to ambient PM2.5.
 

turbobrick240

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The decline in EU new diesel passenger car registrations is quite dramatic. From 89% in 2019 to about 15% in 2023. End of an era.
 

wxman

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The decline in EU new diesel passenger car registrations is quite dramatic. From 89% in 2019 to about 15% in 2023. End of an era.
True, but new diesel car sales increased in Germany by a greater percentage than any other technology compared to the same month in 2023.

 

dieseldonato

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I think the failure of diesel cars to gain widespread adoption in N. America had more to do with the relative cheap fuel costs here vs. Europe and elsewhere. And American's preference for big powerful cars. When fuel costs spiked during the OPEC crisis, diesel auto sales made a significant jump. If you go someplace like Saudi Arabia where fuel is exceptionally cheap, you'll see relatively few diesel cars. Now that the standards have really tightened up, diesels have a tough time. Especially when there are gas cars with no expensive aftertreatment that can manage 40+ mpg.
True, there were quite a few more factors then the just emissions to diesel passenger cars not gaining much traction in the usa. the gas crunch spurred many compact cars to debut id still think gas versiins oitsold diesel by a large margin. With diesel being quite a bit cheaper then gas for a lot of years, it still surprises me they weren't adopted more readily.
I too fall in the I'd rather be driving my gas hog full size suv or truck mentality, but being I'm a cheap arse and put a ton of miles on my daily driver it doesn't make sense to do so. Too few think about practicality these days.
The "hair on fire" presentation in that video after ~22:00 minutes regarding the air quality in Europe is overly dramatic, IMHO. The ambient NO2 levels in 2016 were above the European ambient air quality standards in only 7% of the monitoring locations. Even then, Europe decided to adopt the WHO air quality guidance (AQG) for NO2, but *NOT* for any of the other criteria pollutants. The ambient NO2 AAQS and WHO AQG are set at 40 µg/m3, which is more than twice as strict as the U.S. NAAQS (53 ppb or ~103 µg/m3). No European monitor would have exceed the U.S. NO2 NAAQS, according to that report.

Regarding the assertion that "most" PM comes from diesel engines, a 2015 study in London (Bohnenstengel et al., “Meteorology, Air Quality, and Health in London.” Bulletin of the American Meteorological Society, May 2015) concludes that most of the black carbon (BC) captured at monitoring sites comes from residential wood burning. Even then, the average BC concentration at the most urban location tested averaged 1.9 µg m−3 out of total PM10 of 18.59 µg m−3, only about 10%. PM from diesel engines is about 75% BC according to an EPA study.

In France, two-stroke scooters and wood burning were the biggest contributors to ambient PM2.5.
Your focus is too narrow from a histological prospective. Back in the 80's when diesels were starting to be promoted they had a lot looser emission standards vs gas powered vehicles in Europe, where as the usa kept it much closer. The video narrator may be a bit excitable, however hes fairly accurate in what happened in the early adoption of diesel vehciles in europen nations. Much changed in the late 90- early 2000's to that extent, not just limited to emission standards.
I don't think anyone will debate diesel vehicles are a small part of the larger air quality issues in any part of the world, surely other sources you mention were greater contributors.
 

turbobrick240

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True, but new diesel car sales increased in Germany by a greater percentage than any other technology compared to the same month in 2023.

Yeah, diesel is hanging on in Germany. Still, a 19% share in May and 18% share in June is half the petrol share. A precipitous drop in just a few years.
 

wxman

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Your focus is too narrow from a histological prospective. Back in the 80's when diesels were starting to be promoted they had a lot looser emission standards vs gas powered vehicles in Europe, where as the usa kept it much closer. The video narrator may be a bit excitable, however hes fairly accurate in what happened in the early adoption of diesel vehciles in europen nations. Much changed in the late 90- early 2000's to that extent, not just limited to emission standards.
I don't think anyone will debate diesel vehicles are a small part of the larger air quality issues in any part of the world, surely other sources you mention were greater contributors.
He's the one that picked 2016 (@ ~23:10), which is the year of the EEA report I referenced. Air quality is not really as bad as is being asserted for that year, at least with respect to (annual) ambient NO2 levels. In addition, I still disagree with the statement in that video that diesel engines are the "main" source of fine particulate matter in densely populated areas for reasons given in post #61.

At least five independent studies conducted during the coronavirus lockdown in 2020 documented that ambient NO2 levels decreased significantly, but ambient ozone levels either stayed the same or increased in all cases, some dramatically. Ozone wasn't specifically mentioned, but it's probably the most difficult air quality issue to address.

My personal opinion is that gasoline and diesel vehicles should have different emission standards since the engine-out emission profiles are considerably different. Requiring diesels to conform to emission standards designed for the technical capabilities of gasoline engines is dubious.

The CO2 emission comparison in that video is also misleading. According to another EEA report, "Monitoring CO2 emissions from passenger cars and vans in 2018" - https://www.eea.europa.eu//publications/co2-emissions-from-cars-and-vans-2018 (Page 20, Table 2.3), diesels have lower CO2 emissions in all size categories. The average across all of the size categories is 17.8% higher for gasoline than diesel, if my calculations are correct. Testing by Emissions Analytics concurs - https://www.fleetnews.co.uk/news/en...els-found-to-be-71-cleaner-than-petrol-models .
 

atc98002

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True, there were quite a few more factors then the just emissions to diesel passenger cars not gaining much traction in the usa.
The biggest problem with diesel passenger cars returning to the US is a) still the fallout of Dieselgate and b) for the past few years D2 has been priced severely higher than the highest grade of gasoline. For quite some time in my general area diesel was more than $1 gallon higher than even Premium gas. It's only the past 4-5 months that it's actually returned to where it should be, at or less than RUG. And there's still a few stations here and there that have diesel still much higher than gas for some reason.
 

kjclow

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He's the one that picked 2016 (@ ~23:10), which is the year of the EEA report I referenced. Air quality is not really as bad as is being asserted for that year, at least with respect to (annual) ambient NO2 levels. In addition, I still disagree with the statement in that video that diesel engines are the "main" source of fine particulate matter in densely populated areas for reasons given in post #61.

At least five independent studies conducted during the coronavirus lockdown in 2020 documented that ambient NO2 levels decreased significantly, but ambient ozone levels either stayed the same or increased in all cases, some dramatically. Ozone wasn't specifically mentioned, but it's probably the most difficult air quality issue to address.

My personal opinion is that gasoline and diesel vehicles should have different emission standards since the engine-out emission profiles are considerably different. Requiring diesels to conform to emission standards designed for the technical capabilities of gasoline engines is dubious.

The CO2 emission comparison in that video is also misleading. According to another EEA report, "Monitoring CO2 emissions from passenger cars and vans in 2018" - https://www.eea.europa.eu//publications/co2-emissions-from-cars-and-vans-2018 (Page 20, Table 2.3), diesels have lower CO2 emissions in all size categories. The average across all of the size categories is 17.8% higher for gasoline than diesel, if my calculations are correct. Testing by Emissions Analytics concurs - https://www.fleetnews.co.uk/news/en...els-found-to-be-71-cleaner-than-petrol-models .
Remember that the regulations in Europe were directed at reducing CO/CO2 emissions while the US/Canada regulations were aimed at NOx reductions. Driving down NOx helped kill the light duty diesels.
 

T1MMBOJONES

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i just spent some time in france and was overwhelmed by all the diesel choices. i knew to expect it but was still pleasantly suprised. i dont know if i could see it in the air persay but buildings near roadways were noticeably sootier than even the bad parts of milwaukee. i did some further research and found they are discovering more people die of lung diseases at early ages there. that being said everyone seems to chain smoke and both my non smoking, usa born and raised, parents died young from cancer so its not necessarily better or worse. france left me wondering why anyone would move to the usa from europe....
 
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wxman

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Remember that the regulations in Europe were directed at reducing CO/CO2 emissions while the US/Canada regulations were aimed at NOx reductions. Driving down NOx helped kill the light duty diesels.
Completely agree. Didn't mean to imply that government policies don't affect vehicle technology choices.

Not to belabor the topic, but according to a peer-reviewed paper published by CARB staff in 2015 (Propper et al., "Ambient and Emission Trends of Toxic Air Contaminants in California." Environ. Sci. Technol. 2015, 49, 11329−11339), ambient diesel particulate matter (DPM) concentration in selected monitors in California was ~1.9 micrograms/M3 in 1991, the highest level in the study period (1990 - 2012, Figure 2). The average ambient PM2.5 in 2006 at those selected California monitors was 14.1 µg/m3 according to EPA data (EPA data don't go back to 1991). Even if you assume all DPM is PM2.5, and ambient levels were the same in 1991 as in 2006 (likely higher in 1991), DPM would account for 13.5% of total ambient PM2.5.

I became skeptical that diesel exhaust was the primary source of ambient PM2.5 when I had access to real-time speciated PM2.5 data back in the early 1990s (I was involved in various aspects of air quality from 1985 to 2012, when I retired). All data I saw showed that BC generally made up no more than 10% of ambient PM2.5. If engine-out DPM is ~75% BC on average as EPA estimates, it really can't be a huge source of ambient PM2.5. It may be A source of ambient PM2.5, but not THE source, even before DPFs were effectively required by regulations.
 
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dieseldonato

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I don't think anyone is arguing that diesel powered cars ( diesel vehicles in general really.) Were or are a major contributing factor to air quality issues. simply that Europe and the USA standards were different, and Europe went pretty far out of its way to make the standards for diesel powered cars easier for quite a few years.
 

jkepler

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... france left me wondering why anyone would move to the usa from europe....
I moved from the US to Europe for work, because I wanted to help small Protestant Reformed and Evangelical churches grow and strengthen. I was carless in Ukraine, as public transport served my needs well, but in France my wife and I bought a 6-speed manual Skoda Octavia TDI wagon, which served us well. We named the car "Mistral" after the strong winds in Marseille, because of the engine's strength in contrast to my wife's previous Toyota Yaris hatchback. That said, while there's lots I enjoyed about France, I really like the USA's decentralized approach to freedom.

But after nearly 12 years there (Ukraine, then France), I've moved back to the USA. I'm now in the market for a TDI manual transmission Sportwagen---either ideally the 2015 Golf or a late-model Jetta. I think the 2012 Jetta Sportwagen TDI manual tranmission would be the same engine as what our Octavia had.
 

Matt-98AHU

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Manual transmissions are very scarce.
That they are... The closest thing VW offered to a TDI was the 1.5 TSI the last few years. Can get more than 40 MPG highway pretty easily with the long legged 02S 6 speed they come with (and I've been retrofitting into Mk4s TDIs the last year and a half :LOL:).

But as of the 2025 model year, the base model 1.5 TSI will be automatic transmission only. If you want a manual transmission, you have to buy a GTI or GLI with the brawnier 2.0 TSI. Only cars VW has in our market with 3 pedals anymore...
 

CanadianALH

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That they are... The closest thing VW offered to a TDI was the 1.5 TSI the last few years. Can get more than 40 MPG highway pretty easily with the long legged 02S 6 speed they come with (and I've been retrofitting into Mk4s TDIs the last year and a half :LOL:).

But as of the 2025 model year, the base model 1.5 TSI will be automatic transmission only. If you want a manual transmission, you have to buy a GTI or GLI with the brawnier 2.0 TSI. Only cars VW has in our market with 3 pedals anymore...
Does the R not come with a stick anymore? That would be unfortunate if that’s the case.
 

Matt-98AHU

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Does the R not come with a stick anymore? That would be unfortunate if that’s the case.
R-line is just a trim. As far as I know, anything with the 1.5 TSI will not be offered with a manual starting for the 2025 model year. GLI and GTI only with be offered with the bigger 02Q 6 speed manual.
 

CanadianALH

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R-line is just a trim. As far as I know, anything with the 1.5 TSI will not be offered with a manual starting for the 2025 model year. GLI and GTI only with be offered with the bigger 02Q 6 speed manual.
I meant the Golf R or did they discontinue that for the 2024 model year?
 

Matt-98AHU

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I meant the Golf R or did they discontinue that for the 2024 model year?
Just looked it up, Car and Driver was told by VW that for 2025, there will not be a manual transmission option for the R in North America. DSG only, like the 2008 R32...
 

CanadianALH

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Just looked it up, Car and Driver was told by VW that for 2025, there will not be a manual transmission option for the R in North America. DSG only, like the 2008 R32...
Oh no! The DSG is faster but nothing like rowing your own gears.
 
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