2008 NAIAS: Toyota announces that clean diesel engines are coming

NO, the particulate emission problem was solved years ago. Particulate filters have been used for years in Europe. With a good Particulate filter you have 0 particulate emisions. That is from a regulatory view.

Of course that isn't really true, it's just that the particles are smaller than 2.5 microns and they are not measured. (This is the same as with gasoline cars. Gasoline vehicles put out lots of particulates as well, they are just smaller than 2.5 microns and cannot be seen with the human eye.) Plenty of research has shown that smaller particulates are more dangerous than large ones. So really the EPA is making the emissions from vehicles MORE dangerous to humans but visually more pleasing.

 

I only am responding to this statement since virtually everything you post is very well thought out. Unless the EPA if enforcing a technology (directly or indirectly) that makes smaller particles out of larger ones, I can't see how the EPA is making vehicles "more dangerous". I can see how they are mis-focused on the surface issue.

 

First, I gave the wrong regulatory agency. It is CARB pushing the technology, not the EPA. The EPA will just implement the CARB requirement 2 years latter.

CARB requires that all emission equipment be maintenance free. This requirement rules out the simplest and most effective types of particulate filters that simply filter the exhaust gases and remove the particulates. Since this type of filter needs to be periodically replaced there is the possibility that an owner may just remove the filter instead of replacing it. The manufacturer could just install a sensor that checks for the presence of the filter, but this has been unacceptable to CARB. (The manufacturers are in a similar fight with CARB over the use of urea injection to eliminate NOx emissions.)

In order to make the filters maintenance free, all the systems I know of use regeneration. When the filter starts to load up with particulates, a sensor that check the back-pressure in the exhaust system initiates a regeneration cycle to burn out the accumulated particulates. These can either use fuel, or fuel in conjunction with a catalyst. Either way, the particulates are heated to break them down into smaller, invisible particles.

Most of my information comes from the trade magazine “Diesel Progress†and from working for a subsidiary of Yanmar. (Yanmar is a Japanese diesel engine manufacturer.) Wikipedia has a pretty good page on the basics of Diesel Particulate Filters and so does this company: Technologies - Diesel Particulate Filters

 

That is a sensible answer. I see both sides of the issue. However, it would come down to numbers before you can state that the problem would be worse. Specifically, that adverse environmental impact of one emission approach vs. another. Using your example, if the smaller particulates were twice as likely to induce problems as larger particulates, but the regeneration got rid of 2/3 of the total mass, then that is 'better', but not the best. I do not have a clue to what real numbers would be. CARB's position is understandable due to the great number of vehicle owners that would rather bypass/cripple/ignore any maintenance requirement that can be....by whatever means. Auto shops cutting out catalytic converters was big business in my younger days. (Now trying to keep them from being cut out is the problem.)

 

Just to be fair, there is nothing about the CARB requirements that prevent manufacturers from using a replaceable fine particle filter (to my knowledge). CARB simply specifies that they must meet the PM spec without it. If the diesel manufacturers gave two hoots about our health they could always do both. It seems to me this just illustrates that if there was no CARB spec at all, the manufacturers would just elect to do nothing. The spec may not be perfect, but its probably a lot better than the alternative.

Rob

 

Sorry but as far as I can see "clean diesel" is nothing more than marketing hype. Right up there with "clean coal". It may be cleaner than it was, but thats not really saying much. I am really concerned that people are buying this hype and honestly believe their new diesel is going to save the world. Its kind of sad to see Honda and Toyota heading down that path as well. Lets take a look at how the emissions on a few "new" diesels stack up:

2008 Mercedes E320 Bluetec vs. 2007 Toyota Camry Hybrid
CO2 (g/mi): 387.85 vs. 258.47 (50% higher) Greenhouse/Global Warming Gas
CO (g/mi): 2.88 vs. 0 (inf higher) Poison / Toxic
NOx (g/mi): 0.165 vs. 0.01 (1550% or 16.5X higher) Smog / Acid Rain
NMOG (g/mi): 0.0814 vs. 0.006 (1257% or 13.6X higher) Formaldehyde & other VOCs, irritant, cancer
PM (g/mi): 0.002 vs. 0 (inf higher) asthma, lung development problems in children

2008 VW Toureg Diesel vs 2007 Lexus RX400h 4WD
CO2 (g/mi): 593.18 vs. 338.0 (75.5% higher) Greenhouse/Global Warming Gas
CO (g/mi): 0.08 vs. 0 (inf higher) Poison / Toxic
NOx (g/mi): 0.57 vs. 0.01 (5600% or 57X higher) Smog / Acid Rain
NMOG (g/mi): 0.0176 vs. 0.007 (152% or 2.5X higher) Formaldehyde & other VOCs, irritant, cancer
PM (g/mi): 0.007 vs. 0 (inf higher) asthma, lung development problems in children

2008 Jeep Grand Cherokee 4WD Diesel vs. 2008 Toyota Highlander Hybrid 4WD
CO2 (g/mi): 530.74 vs. 338.0 (57% higher) Greenhouse/Global Warming Gas
CO (g/mi): 0 vs. 0 (even) Poison / Toxic
NOx (g/mi): 0.4 vs. 0 (inf higher) Smog / Acid Rain
NMOG (g/mi): Not Reported vs. 0.008 Formaldehyde & other VOCs, irritant, cancer
HC-NM (g/mi): 0.006 vs. 0.001 (500% or 6X higher) hydrocarbons, water pollution, ground ozone, smog
PM (g/mi): 0.007 vs. 0 (inf higher) asthma, lung development problems in children

2008 VW Jetta TDI
Failed meet minimum emissions requirements, being revised

2006 VW Jetta Wagon TDI vs. 2006 Toyota Prius
CO2 (g/mi): 305.58 vs. 191.04 (60% higher) Greenhouse/Global Warming Gas
CO (g/mi): 0.11 vs. 0.1 (10% higher) Poison / Toxic
NOx (g/mi): 0.55 vs. 0.01 (5400% or 55X higher) Smog / Acid Rain
NMOG (g/mi): 0.0123 vs. 0.009 (37% higher) Formaldehyde & other VOCs, irritant, cancer
HC-NM+NOX-COMP (g/mi): 0.824 vs. 0.03 (2647% or 27.5X higher) composite of main smog ingredients
PM (g/mi): 0.069 vs. 0 (inf higher) asthma, lung development problems in children

What I found most surprising in this analysis was that the Camry, Highlander, and RX400h are all actually cleaner than the Prius (ignoring CO2)! I assume this is just a matter of newer tech, as Prius was a few years older design wise. Hopefully next rev will see the same improvements. The other interesting thing was how bad the Vue Hybrid looked compared to the Escape.

2007 Saturn Vue Hybrid vs. 2007 Ford Escape Hybrid
CO2 (g/mi): 338.0 vs. 292.93 (15% higher) Greenhouse/Global Warming Gas
CO (g/mi): 2.4 vs. 0.1 (2300% or 24X higher) Poison / Toxic
NOx (g/mi): 0.04 vs. 0.02 (100% or 2X higher) Smog / Acid Rain
NMOG (g/mi): 0.062 vs. 0.006 (933% or 10.3X higher) Formaldehyde & other VOCs, irritant, cancer
HC-NM+NOX-COMP (g/mi): 0.05 vs. 0.01 (400% or 5X higher) composite of main smog ingredients

All emissions data is from:
Annual Certification Test Results & Data | Cars and Light Trucks | US EPA
Wherever possible, federal test data at 120 or 150k miles has been used for a fair comparison. CO2 g/mi is calculated from 2008 calc EPA composite mileage using the EPA/DOE conversion factors of 8788 g/gal for gasoline and 10084 g/gal for diesel. These can be found here:
Emission Facts: Average Carbon Dioxide Emissions Resulting from Gasoline and Diesel Fuel | US EPA

Biodiesel helps somewhat, but not nearly as much as people seem to think. It seems like every day I hear some yahoo claiming his H1 running biodiesel has no emissions. According to this data:
http://www.biodiesel.org/pdf_files/fuelfactsheets/emissions.pdf
It reduces most pollutants by about a factor of 2 (not counting NOx which gets slightly worse). Given that many of the diesels above are often worse by a factor of 10-20, that doesn't really even put a dent in the problem. There is also not much basis for the carbon nuetral claims. That _may_ be true if you make your own bd from waste veggie oil using no energy. Sadly we don't eat nearly enough french fries to run all our cars this way. Large scale vegatable oil production will probably require sources like the plam plantations of SE asia, which are an environmental disaster in the making. If its 3X cheaper than American corn or soy bean oil, what do you want to bet thats what people will go with?
Palm oil: the biofuel of the future driving an ecological disaster now | Special reports | Guardian Unlimited

I would really like to be wrong about this. I really want to convert my Land Rover to Diesel and run it on bio. Can't quite seem to rationalize it based on these numbers though.

Rob

 

Just to try and satisfy anyone who may claim the Camry is not a fair equivilent to the E320, here's the GS450h

2008 Mercedes E320 Bluetec vs. 2008 Lexus GS450h
CO2 (g/mi): 387.85 vs. 382.09 (1.5% higher) Greenhouse/Global Warming Gas
CO (g/mi): 2.88 vs. 0.01 (28700% or 288X higher) Poison / Toxic
NOx (g/mi): 0.165 vs. 0.01 (1550% or 16.5X higher) Smog / Acid Rain
NMOG (g/mi): 0.0814 vs. 0.008 (918% or 10.2X higher) Formaldehyde & other VOCs, irritant, cancer
PM (g/mi): 0.002 vs. 0 (inf higher) asthma, lung development problems in children

Incidentally, the E320 data is running the new low-sulfur diesel.

Rob

 

Thanks for the data, Rob, very informative.

That's what I suspect as well.

 

there are also reports now that therse small paticals easyly get in your longs...
i prever bigger becasue then your nose can stop some of it!

 

Gasoline engines are putting out those smaller particles also. You'll only eliminate them with a battery or fuel cell.

The Ford Meta One is a diesel electric hybrid which meets AT-PZEV standards. Unfortunely, it and a lot of hybrids aren't available. How do diesels compare to non-hybrids?

 

2008 VW Jetta TDI
Failed meet minimum emissions requirements, being revised

2006 VW Jetta Wagon TDI vs. 2006 Toyota Prius
CO2 (g/mi): 84.18 vs. 52.63 (60% higher) Greenhouse/Global Warming Gas
CO (g/mi): 0.11 vs. 0.1 (10% higher) Poison / Toxic
NOx (g/mi): 0.55 vs. 0.01 (5400% or 55X higher) Smog / Acid Rain
NMOG (g/mi): 0.0123 vs. 0.009 (37% higher) Formaldehyde & other VOCs, irritant, cancer
HC-NM+NOX-COMP (g/mi): 0.824 vs. 0.03 (2647% or 27.5X higher) composite of main smog ingredients
PM (g/mi): 0.069 vs. 0 (inf higher) asthma, lung development problems in children


Rob[/quote]

This is very interesting stuff. A two week trip to France and a rented Peugeot 407 diesel got me interested in diesel. I came home thinking that the then planned April 2008 launch of the Jetta "clean" TDI would match with my need for a fuel efficient vehicle. The Volkswagen delay and this web site have gotten me re-interested in Prius. The above data virtually clinches it. I will be obtaining a Prius within the next two months.

I look forward to posting when I get it.

I wonder what the diesel enthusiasts on TDI Club.com would say about the data in the above quoted post??

 

Here's the Jetta gas vs. diesel:

2006 VW Jetta TDI vs. 2006 VW Jetta 2.5L 5cyl gas
CO2 (g/mi): 305.58 vs. 399.45 (23.5% lower) Greenhouse/Global Warming Gas
CO (g/mi): 0.04 vs. 0.41 (90% or 10X lower) Poison / Toxic
NOx (g/mi): 0.31 vs. 0.0 (inf higher) Smog / Acid Rain
NMOG (g/mi): 0.01984 vs. 0.0033 (500% or 6X higher) Formaldehyde & other VOCs, irritant, cancer
PM (g/mi): 0.046 vs. 0 (inf higher) asthma, lung development problems in children

So for '06 TDI, its better in some regards and worse on others. The '09 TDI should be better in PM and NOx, but if the Mercedes is any indication they may have to compromise on CO to achieve this. There are also claims that mileage and performance will both be improved, but we'll have to wait and see. In general you would not expect emissions to get better, plus mileage to improve, and performance to improve. I won't say its impossible, but its certainly not how the trade off usually goes.

Often folks point to the European diesels as evidence of the direction things are heading, so here is a comparison of the UK numbers.

2007 VW Jetta 1.9L TDI UK vs. 2007 Toyota Prius UK
CO2 (g/km): 137 vs. 104 (31.7% higher) Greenhouse/Global Warming Gas
CO (g/km): 0.047 vs. 0.18 (73.8% or 3.8X lower) Poison / Toxic
NOx (g/km): 0.191 vs. 0.01 (1810% or 19.1X higher) Smog / Acid Rain
PM (g/km): 0.019 vs. 0 (inf higher) asthma, lung development problems in children

There's also a 2.0L sport TDI offered in UK, which seems more likely to be the engine the new US version will be based on.

2007 VW Jetta 2.0L TDI UK vs. 2007 Toyota Prius UK
CO2 (g/km): 148 vs. 104 (42.3% higher) Greenhouse/Global Warming Gas
CO (g/km): 0.103 vs. 0.18 (42.8% lower) Poison / Toxic
NOx (g/km): 0.239 vs. 0.01 (2290% or 23.9X higher) Smog / Acid Rain
PM (g/km): 0.016 vs. 0 (inf higher) asthma, lung development problems in children

I'm not quite sure why the UK Prius CO numbers seem to be high, if its a test difference or actual equipment difference. Anyway, I used the real UK numbers rather than converting the US numbers just to try and be consistent. The converted US CO number would be ~0.06g/km. Next gen Prius should be 0 if Camry Hybrid is anything to go by.

UK data from:
VCAcarfueldata.org.uk - Home Page

Rob

 

I was in pretty much the same position. We have a Land Rover Discovery (series 1) that we love for driving out in the desert. In the UK these come with a tdi that can get it up to 28-30 mpg. I figured that if I converted mine over and ran it on biodiesel, it would be just as good as driving a hybrid escape, and a lot more offroad capable. After looking at the emissions numbers, finding out about the whole imperial gallons thing, and finding out more about the real deal with biodiesel I could no longer justify going that route.

Its not a 100% fair comparison as tests are probably different, but here are the US numbers for the Escape Hybrid 4WD vs. UK numbers for the diesel Land Rover Discovery converted to US units:

2007 LR Disconvery 3 TDI UK vs. 2007 Ford Escape Hybrid 4WD US
CO2 (g/mi): 392.6 vs. 325.48 (20.6% higher) Greenhouse/Global Warming Gas
CO (g/mi): 0.346 vs. 0.1 (246% or 3.5X higher) Poison / Toxic
NOx (g/mi): 0.525 vs. 0.02 (2525% or 26.3X higher) Smog / Acid Rain
HC+NOx / HC-NM+NOx-COMP (g/mi): 0.566 vs. 0.01 (5560% or 56.6X higher) composite of main smog ingredients
PM (g/mi): 0.079 vs. 0 (inf higher) asthma, lung development problems in children

UK numbers divided by 0.62137 to convert g/km to g/mi.

Rob

 

Sorry, I just realized there was an error in my CO2 calculation. The ratio was correct, but the numbers I had were only the mass of the carbon content. The correct numbers for the CO2 generated have to include the Oxygen pulled out of the air. The correct numbers are 10084 g/gal for diesel, and 8788 g/gal for gasoline. You can find these here:
Emission Facts: Average Carbon Dioxide Emissions Resulting from Gasoline and Diesel Fuel | US EPA

I've gone back and corrected these in the previous posts.

Rob

 

Has anyone taken into account the "cost effectiveness" of clean diesel vs an HEV or even a conventional vehicle? Last time I checked at Chevron in Los Angeles diesel was going for $3.79/gal vs $3.04 for unleaded. Even at $3.50 for diesel vs $3.00 for unleaded regular, diesel better give me 17% better fuel economy over a conventional car just to break even cost wise. Otherwise, why bother?

 

My Jetta TDI has consistently returned the EPA sticker mileage or better. The EPA sticker on my TDI is 45 mpg combined, the comparative gas model is 26 mpg combined. I think I can afford to pay a little extra for diesel in the winter.

That is something no one seams to notice. At least in the Southeast, diesel is less than regular in the summer but more than premium in the winter. In the time that I've had my TDI, diesel has averaged $0.01 more per gallon than regular gasoline. But all you hear is how expensive diesel is in the winter time.

BTW, the UK TDI engines are completely different than the 2009 TDI to be offered in the US. The US 2.0L engine is common rail injection vs. PD on the UK 2.0L. The US engine will have a catalytic converter and particulate filter vs. a previous generation particulate filter on the UK 2.0. You are comparing apples and oranges.

 

diesel in the us more exps.?
here in the EU diesel is a LOT cheaper then gas

 

Diesel may be cheaper in the EU generally, but its more expensive than unleaded in the UK.

 

If you look at the national average diesel is more expensive that regular gasoline. For the last 10 / 5 / 1 years Diesel #2 has averaged $0.05 / $0.09 / and $0.12 more per gallon than regular gasoline.

However, diesel varies greatly in price depending on the season. Diesel is most expensive in Dec and Jan and least expensive in May and June. For example in Jan 2007 Diesel was $0.30 more expensive than regular but $0.35 less expensive in May 2007. A lot of this variation is due to people using heating oil and kerosene to heat their homes in the winter. Since heating oil and kerosene are almost identical to diesel fuel, the price goes up in the winter time due to higher demand.

Diesel is also taxed higher than gasoline. The average US tax for gasoline is $0.39 per gallon compared to $0.47 per gallon for diesel.

BTW, this is all from DOE figures: Gasoline and Diesel Fuel Update

 

Thats good to know. My main point was that there has been a lot of marketing hype about "clean diesels" being a good alternative to hybrids, so to me that makes it incumbent on the marketeers to prove it with data. Based on the data available today, it appears that the new diesels will still be a lot dirtier. Hopefully VWs got some new tricks up their sleeve to match the hype. Given that the 2008 model failed to barely squeek in under the dirtiest emissions spec allowable, I am somewhat dubious. I honestly hope I am wrong.

I was really disappointed by the whole Top-Gear send up of the Prius (particularly because I love those guys), and I fear that this is a common and spreading attitude. Because a VW Polo Diesel gets better mileage than a Prius it must mean that diesels are just as green as hybrids. Never mind the fact that the Polo is smaller (its smaller than the golf/rabbit), slower, has the same CO2 emissions and puts out almost 23 times more smog pollution.

Heres one more comparison...

2007 VW Polo 1.4L Blue Motion UK vs. 2007 Toyota Prius UK
CO2 (g/km): 104 vs. 104 (even) Greenhouse/Global Warming Gas
CO (g/km): 0.237 vs. 0.18 (31.7% higher) Poison / Toxic
NOx (g/km): 0.227 vs. 0.01 (2170% or 22.7X higher) Smog / Acid Rain
PM (g/km): 0 vs. 0 (even) asthma, lung development problems in children
Luggage (cuft): 9.5 vs 14.4 (34% less)
0-60 (s): 13.5 vs. 10.5 (28.6% slower)

I guess we'll just have to wait and see how things look when the real data for the new US VWs comes out.

Rob