I apologize for perpetuating this flame war.

Getting back to the topic of this thread, the point is in my opinion, there is no environmental benefit to holding these European diesel vehicles out of the U.S. market (their NOx emissions are still extremely low, and they have near-zero HC and CO emissions), including California and the other “CARB states”, and I would argue that there’s potentially an environmental disbenefit.

I don't have exact numbers, no. But the Weekend Effect was acknowledged at the DEER 2005 Conference. (PDF file, see Implications and Questions) This presentation includes future emissions projections. A Google search for DEER 2005 Weekend Effect will bring up some other relevant sites. And there's this article as well.

CARB acknowledges it as well. That's not really the question. That PPT from DEER still leaves a lot of open questions. It's still a model.

If this study is correct further NOx reductions won't actually do any good, unless the other smog precursors (like VOCs) can be reduced also.

Pretty sure CARB acknowledges that as well.

And my position on climate change angers people on both sides of the political aisle. I'm used to that by now.

It's not the position, it's the logic of the position. Do you discount unproven scientific theories or not? Climate change theory certainly has been more thoroughly tested and vetted than the weekend effect.

I wonder why they didn't just use the existing Saab 1.9TiD turbodiesel engine, it has virtually the same performance characteristics. It even emits the exact same amount of CO2 in the NEDC test. Either the left hand doesn't know what the right hand is doing at GM or "all-new" is just their marketing department feeding us BS.

Does that sound like an effective regulation to you?

It's hard to tell what the regulation is doing. Tailpipe emissions regulations of light vehicles are only part of the equation with respect to air quality. Still have VMTs, congestion, power plants, and heavy vehicles, among many things.

Thus, whereas ROG control is never detrimental, NOx control can be detrimental, particularly in the central cores of urban areas...

I agree with that.

I actually have a great deal of respect for EPA scientists, but the regs aren't written by them - they're written by regulation writers. It's my concern that a lot of politics gets involved at that point and "dilutes" the science.

I understand that, too, but I'm wondering how there'd be some sort of coherence between CARB and EPA regulatory changes towards greater restrictions, especially in the current political environment. What would the current EPA's political motivation be to have irrational emissions regs that raise costs for auto manufacturers, fuel suppliers, and so on? Why would CARB do that as well?

Tailpipe emissions regulations of light vehicles are only part of the equation with respect to air quality.

That's true except that nearly all anthropogenic CO in urban areas is from gasoline vehicle emission (http://www.epa.gov/air/airtrends/aqtrnd01/summary.pdf) and nearly all CO is anthropogenic. I don't see how California is going to get those ambient CO levels down ("serious" non-attainment with the CO NAAQS is defined as nearly twice the NAAQS limit), unless they mandate that all old gasoline high-emitters are removed from the road, and are continued to be removed as the newer cars become old high-emitters, which would probably be prohibitively expensive.

Actually, the same argument could be made of NOx emissions from diesel cars. According to EPA's National Emission Inventory (2002 is the latest available), light-duty diesel trucks and cars were responsible for 16K tons of NOx emissions out of a total inventory of over 21 million tons of NOx emissions. That's 0.076 percent. Diesel cars and pickup trucks currently make up approximately 3% of the total vehicle population in the U.S., so even if you increase the diesel vehicle population to 50%, that's still only about 1% of the total NOx emission inventory, even if you assume all diesels still emit at pre-2002 levels. So mandating an order-of-magnitude reduction in light-duty NOx emissions would not result in a significant overall NOx reduction even if the U.S. was to make a huge transition to diesel like Europe.

As far as CARB and EPA tailoring their regs the way they did, I think it's precisely because of input from the auto manufacturers, although that's just speculation on my part.

That PPT from DEER still leaves a lot of open questions. It's still a model.

While I don't think emitting more NOx is a good idea, I really don't know why so many people have a hard time with VOC and NOx saturated regimes of ozone production. It's been well established for, oh, well over a decade. The turnover point depends on the concentrations of each, the VOC speciation, and temperature, so there's no simple rule. All urban cores in the US and elsewhere (at least where they've looked, even Mexico City with its huge NG emissions) are VOC limited. No surprises there.

Something I've found interesting is the difference between the CARB/EPA and Euro emissions standards wrt vehicle size. In the states we have a blanket set of emissions standards the preclude small diesels from being sold, but for larger vehicles the allowed NOx levels are way above the Euro levels for the same vehicle size, and classify vehicles people use for daily transport as heavy duty.

Essentially, if it's an F-350 or the like, our NOx regs aren't as restictive as Euro standards, so it seems very one sided here, especially when considering that. There also seems to be some leeway in terms of different engine types according to the Euro standards... Higher levels of CO/HCs are allowed for gasoline cars, and higher levels of NOx are allowed for diesels, to reflect the advantages and disadvantages of both engine types.

In any event, we have some nutty regs that allow for larger trucks to run around spewing NOx, while limiting the sales of small passenger diesels. Europe seems to be approaching it with a bit more common sense...

Carl, Cervus:

California (and other 10 states, and EPA closely following), is moving slowly but surely to way more restrictive SULEV emission standards from current LEV2. For passenger cars and LDV after 120 000 miles /11 years caps are as follows, NMOG, CO, NOx correspondingly, g/mi:

LEV2: 0.09 4.2 0.07

SULEV: 0.01 1.0 0.02

As you see, reduction in VOC is 9 times, while reduction in NOx is 3.5 times. In addition, evaporative emissions from SULEV vehicles will be virtually zero. Some cars are already certified, and not only hybrids like Prius and Civic, but “bread and butter” subcompacts such as Sentra, Corolla, and Civic. Nothing revolutionary involved, just fine-tuning of existed pollution control equipment.

It seems to me that CARB is trying to minimize FUTURE emissions of ANY pollutant, not only the one which appears to be most troublesome right now. And I totally agree with such approach, especially considering how painfully long and complicated is process of imposing new emission legislation.

BTW, it is possible than they will exclude diesel powered vehicles from SULEV.

a small diesel would probably yield better economy because of our need for longer trips and the virtual lack of stop-and-go in most cases

That's somewhat of a myth. Stop and go in a hybrid yields better fuel economy than regular vehicles because of the auto engine-off and a little regen braking, but the big savings in fuel use come from highway driving because of the downsized (and often Atkinsonized) engine. It's similar in concept to downsizing with turbochargers, except the ICE doesn't produce the extra power.

As a Prius driver, The notion that the Prius is better in the city is somewhat of a fallacy. (at least for my driving pattern).
I believe EPA is 60 city, 52 highway.
After 20,000 miles of records, I find that I average about 48 in the city, and 52 on the highway.
I can beat EPA on the highway, but around town, we're always under 50 due to the warmup period of the car (and the cold weather in MN). It doesn't use the electrical tricks until you've been on the road for 5 minutes and most driving around town is only 5-10 minutes long.
To get the 60 MPG in city, you'd have to tool around town for extended periods of time like a slow taxi cab would.
Long story short, the Prius would only slightly beat this deisel in highway mileage. If that's all you did, than the diesel would be a better fit due to lower cost.
(Unless you factor in the credits, resale value, and reduced emissions).

I got 57mpg traveling at 65mph from Rock Springs, Wyoming through Big Sandy, Wyo, back thru Rock Springs and on to Fort Collins, Colorado. I find the best mileage in my Prius is highway driving. I also got 56 mpg traveling from Grand Junction, Colorado to my home in Allenspark, Colorado and that was traveling over the mountains with a net gain in altitude. From my personal experience, the knock on the Prius for highway driving is the product of some very misinformed or ill intentioned people.

Get real folks. The current fleet average for all registered autos in the mid 16mpg range. Arguing about diesel vs hybrid is an exercise in irrelevant trivia. It's all good and will get better as soon as diesels start complying with the latest EPA regs.

I don't care. Drive a diesel. Drive a hybrid. Anything to get rid of the existing gas hogs.

I stand corrected.

T,
Outfit a Prius, Insight, or any low drag lightweight vehicle, with a modern clean efficient turbo diesel, and it will get similar, if not better, highway mpg.

A prius is not a lightweight vehicle. It is astonishing to think that ~2900lbs is now considered to be lightweight.

I checked some mileage numbers from local dealers webpages (here in Europe manufacturers must publish these numbers).

On a highway, Prius gets 4.2 liters/100 kms.

A VW Polo 1.4TDI (a bit smaller than Prius) gets 3.9 liters/100 kms. Golf/Jetta 1.9TDI gets 4.3, a Honda Accord 2.2 CTDi gets 4.9, and a 2.0 TDI Passat 4.8 liters/100 km. The diesel numbers are for manual gearboxes.

I have a 2006 Passat Variant 2.0TDI with DSG (autobox). The engine developes 140 bhp and 340 NM of torque. On city/hw combined I get around 6 liters/100 kms, on higway around 5 liters/100 kms.

What a sneaky way to block Diesel Imports.

1) Allow dirty Diesel fuel oil at the pump.
2) Set overly strict VOC and NOx standards
3) To extend the effectiveness of this type of import restrictions, make the standards stricker just before European cars manage to meet them and so on.
4) Meet with GM/Ford/Chrysler for more new tricks etc.

Wonder what will be used to block-restrict import of ICE Hybrids and PHEVs and EVs. Public-pedestrians danger due to low noise emission? Potential battery explosion hazard? High Voltage danger? Performance display distraction. etc.

Harvey D. -

though I do suspect all emissions regs these days feature an element of trade protectionism, I don't think you're being entirely fair.

(a) EPA just forced US refineries to switch to ULSD, a key enabler for modern LDV turbodiesel engines and their aftertreatment systems. The only thing dirty about diesel fuel in the US today is the area around the dispenser at the filling station. If and when sales depend on it, franchisees will very quickly clean it up or add it as a new fuel grade altogether.

Btw, Mercedes-Benz recently drove a bunch of E-Class cars from Paris to the Beijing auto show to demonstrate the ruggedness of their diesels. They had to bring their own tanker truck because standards enforcement for diesel quality is still horribly lax in China.

(b) EPA and CARB are both charged with fighting airborne pollution. While you can argue about how useful further tightening of the regs is wrt population health, it is not their fault there is no mechanism for getting old vehicles off the road (other than really gross polluters). Even with adequate maintenance, one 15-year old truck may emit as much as 2 or 3 brand-new ones.

(c) EPA announced that Tier 2 Bins 9 through 11 would be dropped for LDVs at the end of MY 2006 a long time ago. Carmakers were not caught by surprise, the technology breakthroughs required to meet the deadline simply didn't arrive in time. MB's current E320 CDi BLUETEC (with NOx store cat) very narrowly missed the magic T2B5 level. As T2B6, it may not be sold in CA, NY, MA, VT and ME, which together comprise roughly 1/3 of the total US market. Having honestly tried and failed, EPA apparently relented on allowing SCR systems, for which DCX holds some patents. Their resistance had been based on concerns about the distribution infrastructure and system defeats by drivers who did not care to spend any money on the urea additive.The next-gen SCR systems currently in development store the urea in powdered rather than dissolved form, avoiding cold weather problems and significantly extending refill intervals.

(d) GM/Ford/Chrysler are not actually getting all that many breaks from the current federal government or from California, except with regard to pushing the purported hydrogen economy. In particular, the President wasn't willing to even meet with them before the elections, to avoid being cornered into a health care bail-out and bad-mouthing the Japanese who are buying dollar-denominated financial assets to avoid having the yen appreciate. In effect, they and the Chinese are subsidizing the US budget deficit.

(e) I am not aware of any restrictions on imports of ICE hybrids, nor any plans to specifically block PHEV or BEV imports. On the contrary, the federal government is handing out tax credits and CA awards ZEV quota credits plus carpool lane privileges for hybrid buyers, regardless of brand.

er, the polo is a bit smaller in cabin/trunk space vs. a prius, if a bit = 40%

Ok, it is very late on this one but ...

I've just looked this up on the "Whatcar.co.uk" website where it has the report as follows
"The hatchback achieves 49.5mpg on average, while the estate is only marginally less economical at 47mpg. Carbon dioxide emissions are 149g/km for the hatch, putting it into the 19% company car tax bracket, and 154g/km and 21% for the estate."
However, the gallon they refer to is the UK gallon, not the US gallon. This would equate to approx 40 MP(US)g.

Quite a difference IMHO.

er, vw golf & jetta are also smaller in passenger volume vs. a prius

I don't think Prius is bigger than Jetta... Well, Golf Variant (=estate) is bigger than Prius. Both sit 5 persons, but Golf's boot is much bigger. It's mileage is 4.3 liters/100 kms. Or Citroen Picasso, a strange looking "space wagon", bigger than Prius, 4.3 l/100 kms. Or Citroen C4 Picasso for 7 persons, mileage 5.1 l/100 kms, etc...

Prius is all good, but one can get equally good hwy mileage from modern diesel cars. That is why Prius is not a big seller here. On stop & go traffic Prius is of better.

nadaguides.com shows a 2006 jetta passenger volume of 91 vs. 2006 prius 96.2

Maybe Prius is not a big seller in the EU because the diesel industry favors domestic car makers and the higher PM from diesel is not oft discussed as a great concern on your side of the Atlantic.

great car.y drive chevrolet laceti diesel sedan.y give 10 point from 10. engine 2000 is perfect for this car.good lock.

great car. y drive CHEVROLET LACETti sedan diesel 2000 tdci .y give 10 point from 10. good lock.