How do diesel engines compare to gas on pollution

[wyvrn]

I got to thinking about this after reading This article I have a few questions. I know diesel engines are more efficient than gasoline engines. But don't they also produce more pollution per gallon used? If so, would this additional pollution negate the increased efficiency, in regards to our environment? Is diesel a form of gasoline or is it based on a natural gas or other resource? I used to have a Mercedes 300sd turbo diesel and I still know nothing about diesel fuel or engines 😱

According to the article, US diesel fuel is up to 10x more polluting than Europe's. But it does not directly compare diesel (either US or European variety) to gasoline. I also find this quote interesting:

And with the price of fuel up to three times as cheap in the United States than in parts of Europe, fuel economy is a low priority for many Americans.

That seems to indicate Europe can withstand the higher levels of pollution for diesel engines because they don't drive as much, but what effect would wide use of diesel engines have in America? Another interesting quote:

New U.S. regulations will make cleaner diesel fuel available in a few years, and "particle traps" under development could catch most of the dirty emissions from diesel engines before they are released into the air.

Well, could we not use the same particle traps with gas engines? I assume we have not done so because it robs power or some other reason that lobbyists have blocked such legislation. Does installing these particle traps on diesel engines then negate the increased torque and efficiency we get from them?

Please inform the dummy 🙂

 

[StageLeft]

I think that currently they are less polluting than gas engines, although obviously a 90 HP diesel can't be truly compared to a 190 HP gas, but I think that a VW TDI for instance is pretty clean.

 

[wyvrn]

Ok. Have any links? I have been hearing that assertion a lot, but cannot find statistical data to back it up.

Originally posted by: Skoorb
I think that currently they are less polluting than gas engines, although obviously a 90 HP diesel can't be truly compared to a 190 HP gas, but I think that a VW TDI for instance is pretty clean.

 

[StageLeft]

Originally posted by: wyvrn
Ok. Have any links? I have been hearing that assertion a lot, but cannot find statistical data to back it up.

Originally posted by: Skoorb
I think that currently they are less polluting than gas engines, although obviously a 90 HP diesel can't be truly compared to a 190 HP gas, but I think that a VW TDI for instance is pretty clean.

No I think a VW dealer told me 😱

 

[wyvrn]

Hmm, I would consider that a quasi-informed, quasi-honest source 🙂

Originally posted by: Skoorb

Originally posted by: wyvrn
Ok. Have any links? I have been hearing that assertion a lot, but cannot find statistical data to back it up.

Originally posted by: Skoorb
I think that currently they are less polluting than gas engines, although obviously a 90 HP diesel can't be truly compared to a 190 HP gas, but I think that a VW TDI for instance is pretty clean.

No I think a VW dealer told me 😱

 

[Evadman]

Diesel is a fuel, not a type of gasoline. Diesel has an extreamly low octane rating (around 40 IIRC) and auto combusts when it is sprayed into the combustion chamber at pressures aprocing 5000 psi. it is not premixed with the air before entering the cyl.

Diesel's tend to produce more particulates than gasoline, but other than that, I am not positive on the amount of other emisions produced.

US diesel fuel is high in sulfer which makes it so a catolitic converter can not be run. if the US used low sulfer diesel, the cat would help immensly. they are used in europe.

 

[wyvrn]

Great thanks! So low sulfur diesel helps, and is obviously available. But still I wish there existed a comparison study with hard data on good diesel and gasoline before I would consider buying another diesel.

Originally posted by: Evadman
Diesel is a fuel, not a type of gasoline. Diesel has an extreamly low octane rating (around 40 IIRC) and auto combusts when it is sprayed into the combustion chamber at pressures aprocing 5000 psi. it is not premixed with the air before entering the cyl.

Diesel's tend to produce more particulates than gasoline, but other than that, I am not positive on the amount of other emisions produced.

US diesel fuel is high in sulfer which makes it so a catolitic converter can not be run. if the US used low sulfer diesel, the cat would help immensly. they are used in europe.

 

OK Dummy, here is the lowdown ;


Diesel engine and Gasoline engines make the almost same amount of pollutants (Different types of pollutants), gasoline engine are at the this time cleaner because of Catalytic Convertors and precise fuel and ignition management, these convertors have precious metals in them that once heated up to operating temperature convert the hydrocarbons, nitrogen oxides and carbon dioxide into water vapor and carbon monoxide.

The VW TDI is much cleaner than the standard diesel because of it's advanced electronic fuel management, this is a step in the right direction for diesels 🙂

 

[ToBeMe]

Here ya go!😉 Been looking at replacing my V10 powered F350 super crew with the deisel version so been doing some looking lately.................

Diesel Engines and Public Health

 

[StageLeft]

at pressures aprocing 5000 psi

I thought that diesel engines were only a few times higher in compression than gas, like maybe 30 psi?

 

I thought that diesel engines were only a few times higher in compression than gas, like maybe 30 psi?

You are speaking about compression pressure, not compression ratio 😉

The average gasoline engine has a 8.5 to 11 to 1 compresion ratio, diesels start at 18.5 to 1 and can range up to 23 to 1.

 

[wyvrn]

Extremely informative article. An interesting quote:

The public-health problems associated with diesel emissions have intensified efforts to develop viable solutions. But while improvements to existing diesel engines and fuels are necessary, they are not a long-term solution. Alternative fuels and advanced engines can provide larger gains. Fortunately, these new low- or no-pollution technologies are winning acceptance as alternatives to major new investments in diesel-based solutions.

and

Light vehicles. While diesel powers relatively few automobiles or light trucks today, industry and government are currently working to reintroduce this technology into passenger vehicles to meet fuel economy and climate change goals. But advanced technologies such as battery, hybrid, and fuel cell electric vehicles powered by alternative fuels provide better solutions to air quality, climate change, and energy security problems. Research into advanced vehicles should therefore focus on these inherently cleaner choices. At a minimum, regulators should close historic loopholes that permit diesel cars to pollute more than those powered by gasoline. Government policy should also target the largely untapped potential for improving gasoline vehicles while working to help bring truly clean and efficient vehicles to market.

and

Diesel engines emit large quantities of particulate matter (called PM) and nitrogen oxides (NOx), the latter a precursor to particulates and smog. Collectively, diesel-powered vehicles account for nearly half of all nitrogen oxides and more than two-thirds of all particulates from US transportation.

and the whole section on health impacts was good. So, diesel as we know it now, according to the link, is not as clean as gasoline. With cleaner diesel and technology, diesel can burn cleaner though we still do not know HOW CLEAN the cleanest diesel engine is.

With alternative technologies, is diesel going to be a player in the US market?

Originally posted by: ToBeMe
Here ya go!😉 Been looking at replacing my V10 powered F350 super crew with the deisel version so been doing some looking lately.................

Diesel Engines and Public Health

 

[Evadman]

Originally posted by: Skoorb

at pressures aprocing 5000 psi

I thought that diesel engines were only a few times higher in compression than gas, like maybe 30 psi?

I meant the fuel is injected at up to 5000 psi or so. not that the air pressure in the cyl is 5000 psi.

 

Quote

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Diesel engines emit large quantities of particulate matter (called PM) and nitrogen oxides (NOx), the latter a precursor to particulates and smog. Collectively, diesel-powered vehicles account for nearly half of all nitrogen oxides and more than two-thirds of all particulates from US transportation.
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and the whole section on health impacts was good. So, diesel as we know it now, according to the link, is not as clean as gasoline. With cleaner diesel and technology, diesel can burn cleaner though we still do not know HOW CLEAN the cleanest diesel engine is.

With alternative technologies, is diesel going to be a player in the US market?

You are not considering the amount of diesel powered tractor trailers that are operating in the U.S. 🙂
In the past ten years, the emissions emitted from large diesels have been cut by 75% through the use of electronic fuel system management and ceramic combustion chambers.

 

[ndee]

The normal Diesel engine may contain some making-cancer particles.

 

[Evadman]

Originally posted by: ndee
The normal Diesel engine may contain some making-cancer particles.

Like iron and chrome moly? hell, those valves can be cancer causing. 😛

 

[ndee]

Originally posted by: Evadman

Originally posted by: ndee
The normal Diesel engine may contain some making-cancer particles.

Like iron and chrome moly? hell, those valves can be cancer causing. 😛

nah, I mean... after the pollution comes out of the exhaust, there are particles which can cause cancer.

 

nah, I mean... after the pollution comes out of the exhaust, there are particles which can cause cancer.

So can older vehicles without convertors and modern fuel injection.

 

[ndee]

Originally posted by: Roger

nah, I mean... after the pollution comes out of the exhaust, there are particles which can cause cancer.

So can older vehicles without convertors and modern fuel injection.

Well that's what just what I hear on the news. Here in Switzerland, they want to make a obligation on all diesels, to install a filter which filters those particles.

 

Well that's what just what I hear on the news. Here in Switzerland, they want to make a obligation on all diesels, to install a filter which filters those particles.

I wish them luck, it would be wiser to continue the advancement of electronically controlled diesel injection along with modified convertors 🙂

 

[Eli]

Originally posted by: Skoorb

at pressures aprocing 5000 psi

I thought that diesel engines were only a few times higher in compression than gas, like maybe 30 psi?

What exactly do you mean?

Depending on engine design, you can get up to 200lbs/square inch.. possibly more, although I've never seen it.. in a mechanically sound engine.

Normal is around 120 - 150lbs/sq. in, less in a worn engine.

I can only imagine what diesels produce... I've never compression tested a diesel. 😉

 

I can only imagine what diesels produce... I've never compression tested a diesel.

Depending on the compression ratio, if it's a turbo and the amount of camshaft overlap, you will see comression pressures ranging from 200 P.S.I. to 500 P.S.I.

 

[Thegonagle]

All you need to do is drive behind a VW TDI, and you'll smell that they're not as clean as gasoline engines.

The US needs to get with the program on catylists and low sulfur fuel, but the trucking/transportation lobby is against it. Too expensive to change over. Yeah, they said that same thing about taking lead out of gasoline, too. I say that the sooner we take the plunge, the sooner we'll get over the hump as far as initial costs go. Just like unleaded gasoline, it will be phased in over time. Is anyone still complaining about the great costs to our economy of unleaded gasoline?

 

All you need to do is drive behind a VW TDI, and you'll smell that they're not as clean as gasoline engines.

That's the high sulfur content in the diesel fuel that is sold in the U.S. that you are smelling.

 

[Thegonagle]

Originally posted by: Roger

All you need to do is drive behind a VW TDI, and you'll smell that they're not as clean as gasoline engines.

That's the high sulfur content in the diesel fuel that is sold in the U.S. that you are smelling.

Yeah, that's a "high" that doesn't feel so good.