A&Q about 350Z
Q:
Define "clean." They burn cleaner with fewer emissions already. Some still put out more NOx, but almost all of them coming out now have intercooled EGR that keeps them cleaner than gas. Put it this way; the new Toyota 1.6T diesel that is being developed puts out fewer emissions than any of the hybrids on the road today.
A:
as far as emissions go i believe that most people pay more attention to what they can see than what they can't; when the exhaust pipe of a vehicle is pouring black stuff everyone assumes that the engine is terrible for the environment. particulate emissions can be a problem, but fortunately the new diesels are addressing that problem. tuning the injection pump to a setting that is below the engine's smoke threshold is a good practice, but it severly limints the power output, in my opinion the turbo route is the way to go for power output and particulate control, though that does nothing for NOx emissions at least the exhaust looks cleaner. diesel engines carbon monoxide emissions are almost always lower than gasoline engines emissions.
for anyone concerned, i haven't had the fortune of obtaining any vegetable oil that makes the exhaust smell like french fries, at best it smells like chicken fat burning on the grill, but much more concentrated.
A:
It's the soot and particulates.
Diesels simply do not meet pending ULEV standards because of them. There are devices that will enable diesels to meet such standards, such as urea traps, but they introduce other problems, they are not 'passive' and require periodic maitenance.
Such maitenance costs the owner time and money without affecting vehicle performance, so there is little incentive for the owners to do so unless there is some kind of frequent emissions enforcement.
Sure, I know, you may want to heap scorn on ULEV standards, but we all must breathe the air and we should do what we can to protect it and ourselves.
And yes, I have owned many diesel vehicles, both new (2003) and old. I know how much they have improved, but IMO it's not enough.
Finally, my nose says these engines, even the newest ones stink. Even driving several car lengths behind them, when the exhaust has been diluted many times over by the surrounding air; they still stink.
How good is it for the environment and the health of people if my inaccurate, 40 year-old nose can easily detect such pollution?
A:
All respect intended, but whoa there buckaroo.
The ULEV standards are biased toward all particulates, but soot (which is the main component of diesel exhaust) is heavy and relatively harmless. It falls to the ground, poses no environmental threat, and its the very thing that makes most folks think diesel is bad. Just because you can see diesel exhaust doesn't make it bad, and just because you can't see your gasoline exhaust doesn't make it harmless.
Just because it is easy to smell doesn't mean its bad for you. Skunk smells much more prolifically than diesel and its not bad for you. Plus, you have to consider all of the emissions in question... Diesels are on par with gasoline out the tailpipe, but factor in the cleaner refinement process, and the fact that diesel has a very low vapor pressure. You have to consider the amount of gasoline that evaporates from tanks in many cars and the vapors lost during refueling. Diesel is very slow at evaporating. So, in addition to many diesels being cleaner out the tailpipe, they're cleaner in almost every other aspect as well.
A:
Okay, I have to call you on this one. (Yes, I know the diesel argument is like a bee under my bonnet,
but my experience with the 11 diesel powered vehicles I have owned over the years tells me its a serious issue.)
Nobody ever said gasoline exhaust is harmless, hence the need for the ULEV standards which the government wants to put in place.
However, the technology used to clean up gasoline exhaust combined with the nature of gasoline combustion is fundamentally cleaner than that of diesel engines.
I am not saying to ban diesels. Just clean them up!! The technology exists to do so, but it should be implimented. It must be implimented to meet ULEV standards.
These ULEV standards are designed to protect you, me and the environment. They are not arbitrary. They are based on extensive research to reduce harmful byproducts of combustion. Diesel engines should be included to meet these standards.
Why? Because diesel exhaust in particular is of concern due to the harmful nature of the soot and paricles involved.
"Relatively harmless" as you point out implies relative to what? They are relatively harmless in comparison to Charles Manson's loaded gun, maybe,
but not harmless compared to the clean air that I prefer to breathe.
Diesel exhaust is dangerous, so says the California Air Resources Board.
Fact Sheet
October 1998
The Toxic Air Contaminant Identification Process:
Toxic Air Contaminant Emissions from Diesel-fueled Engines
The Air Resources Board (ARB or Board) is the state agency responsible for protecting the public’s health from
exposure to toxic air contaminants. Toxic air contaminants (TACs) are those air pollutants that may cause or contribute
to an increase in death or serious illness or may pose a present or future hazard to human health.
Current Status of the Identification of Toxic Air Contaminants
from Diesel-fueled Engines
On July 30, 1998, the Board heard the ARB staff proposal to consider the
listing of diesel exhaust as a TAC. At the hearing, the Board received testimony that the listing of whole “diesel exhaust” was too general and included many
harmless substances, such as water vapor and nitrogen. In response to these comments, staff determined that the listing could be clarified to focus on the pollutants that are the most likely contributors to adverse health impacts. These
are the particulate and organic vapor phase emissions.
• Emissions from diesel-fueled engines come from internal combustion engines burning diesel fuel and are
made up of a complex mixture of thousands of gases, vapors, and fine particles.
Why are emissions from diesel-fueled engines of concern to the public?
• Emissions from diesel-fueled engines are mainly composed of particulate matter and gases, which contain
potential cancer-causing substances such as arsenic, benzene, formaldehyde, nickel, and polycyclic aromatic
hydrocarbons.
• Emissions from diesel-fueled engines currently include over 40 substances that are listed by the U.S. Environmental
Protection Agency (U.S. EPA) as hazardous air pollutants (HAPs) and by the ARB as TACs.
• Particulate matter (PM) from diesel-fueled engine emissions is small enough to be inhaled deep into the lungs.
• Approximately 27,000 tons of PM10 from diesel-fueled engines are emitted into California’s air each year.
What are some of the health effects of exposure to emissions from diesel-fueled engines?
• Research studies show that emissions from diesel-fueled engines may cause cancer in animals and humans.
• Studies show that workers exposed to higher levels of emissions from diesel-fueled engines are more likely to
develop lung cancer.
• In 1990, the State of California, under Proposition 65, identified diesel exhaust as a chemical known to cause
cancer. The Proposition 65 program is operated and enforced separately from the AB 1807 program.
• The International Agency for Research on Cancer has concluded that diesel engine exhaust probably causes
cancer in humans.
• The U.S. EPA has proposed classifying diesel exhaust as a probable human carcinogen.
• There is also a link between emissions from diesel-fueled engines and non-cancer damage to the lung.
For more information on TAC emissions from diesel-fueled engines, call the ARB Public Information Office
at (916) 322-2990 or check ARB’s web site at
.
California Air Resources Board 2020 L Street, P.O. Box 2815 Sacramento, CA 95812
Diesel fuel does have some advantages. As you say it evaporates more slowly, and it is safer in a crash due to its low flash point.
I know diesels are much cleaner than they used to be. That's great.
However, they can be made cleaner than they are now, and there is ample evidence to say this is a good idea. This is one example of how our society can make progress to become better for the people who have to live in it.
Finally, sure, skunks stink and are not harmful. But skunk odour is not the byproduct of combustion. It's the combustion process that produces harmful compounds, whether its cigarette smoke or diesel exhaust.
A:
Plus skunk smell sticks with you a long time
You are entirely correct. My argument was speaking primarily of the new diesel standards, but that only accounts for maybe 2% of the diesels on the road. You are right: at the time of that 1998 EPA release diesels were somewhat unregulated and a "free ride" out of the smog debacle.
I agree that diesels need to clean up, but I think the new technologies coming out along with the new standards mean that we're currently there... its just that those new technologies have yet to trickle on to the street.
That EPA publication just earned this thread an addition to the sticky
A:
Thank you for not pointing out that I'm a selfish bastard.
I obviously like driving diesels, I just hate being behind them.
As you say, the technology exists to make them even cleaner. They will need to be cleaner to meet the new, tighter ULEV standards, that are pending (next year, I think)
I hope this is achieved because I would really like a clean running diesel SUV
A:
Maybe we can lobby congress to enact the "diesel air freshener law." Every diesel equipped vehicle must have a permanent air freshener installed in the exhaust. We'll call it the "MagicRat law." Just think of the aftermarket applications. We could market coconut, tea rose, and fresia to start with, then branch out with citrus, chocolate, and ylang-ylang for our sophomore year.
A:
And there is my new sig...............
A:
do diesels have catalytic converters? wouldn't they help remove some of the NOx emmissions? that way couldn't they turn up the boost to get a cleaner burn with no CO or soot and have lowered NOx emmissions.
I'd get skunk air "freshener"
A:
Yes they have catalysts. The higher pressures though would increase NOx. Intercooled EGR is helping that problem. There are also scrubbers that capture soot that are anywhere from useless to highly effective, but they require maintenance and are only as good as the owner keeps up with.
A:
actually i found the answer to my ? on that arb website.
it shows some filters and its effect on performance and fuel economy. fuel economy remains untouched while soot was reduced by 99%, other harmful emmisions were reduced by 68% overall.
A:
Some of the most effective catalysts use urea or ammonia in their function, but they are only just being used on some Eurpoean diesels and are very rare right now in N. America.
This shows some of the latest technologies and devices used, mostly, it seems, in some overseas markets:
My hissy-fit posts shown above rant on about why such devices should be manditory here. Progress is being made, though:
A:
audi is going to Le Mans in '06 with a 5.5 litre V12 diesel based on the outgoing R8, the new one is the R10. i'll type in specs tomorrow.