On the news last week there was a story about the rise in gas prices and the increasing popularity of diesel powered vehicles. They stated that diesel fuel produced less greenhouse emissions but cause more smog. Okay I am a little confused about this, what is better for the envirnment diesel or gasoline? Both my vehicles are diesel, not planning to sell either in the near future but I am curious. I'm doing my part by riding my bike to work just drive when I have to.

 

The main "greenhouse gas" produced by motor vehicles is CO2 (carbon dioxide). Diesels emit less CO2 than an equivalent gasoline fueled vehicle.

For conventional air pollutants are:

Diesels emit more NOX (oxides of nitrogen) and particulates than an equivalent gasoline fueled vehicle.

Gasoline vehicles emit more HCs (hydrocarbons) and CO (carbon monoxide) than an equivalent diesel fueled vehicle.

Conventional air pollutants are what cause the air pollution that you breath "smog". Greenhouse gases do not cause air pollution, they are suspected as the cause of the somewhat controversial global climate change.

Current air pollution regulations in the USA require that by 2007 diesels emit no more conventional air pollutants than equivalent gasoline fueled vehicles.

Diesels are more popular in Europe because over there they are just as clean as gasoline vehicles, they get more MPG, and fuel costs about $5.00 per gallon.

Once clean diesels are available in the USA they will become more popular here. However, as long as fuel prices "stay low" in the USA, diesels are not expected to reach the market penetration of Europe because most people won't buy diesels due to the premium for initial cost of a diesel engine is still a few thousand dollars.

 

Thanks for the reply. I'm still a little confused, if diesels emit more NOX and particulates but less HCs and CO which conventional air pollutant causes the most air polution? Would that be the particulates?

Why don't we have clean diesels here?

I suppose if the greenhouse gas theory is correct driving a diesel is not necessarily worse than gas, just causes different problems.

No doubt the bike causes the least problem. The problem is that on those hazy smoggy days riding the bike is no fun because it's hard to breathe.

 

[QUOTE]Originally posted by javabeanjava
Thanks for the reply. I'm still a little confused, if diesels emit more NOX and particulates but less HCs and CO which conventional air pollutant causes the most air polution? Would that be the particulates? [QUOTE]

Most people are confused about the environmental problems like air pollution and the government and environmentalists turn the issues into politics and don't make it easy to understand.

The air pollution problems vary depending on where you live. The typical brown haze of say Los Angeles is caused by a combination of NOX and HC. This pollution is considered the most pervasive and difficult to control.

Particulates from diesels are a suspected/known carcinogen and in my opinion are the biggest direct health threat.

CO is typically a winter only problem and the least concern in my opinion.

[QUOTE]Originally posted by javabeanjava
Why don't we have clean diesels here? [QUOTE]

In my opinion it is because the diesel industry was very effective in fighting efforts to make diesel cleaner until just a few years ago. That's all history now and by 2007 on road diesel will be as clean as gassers. The big unknown is what will be the impact on diesel performance, maintenance, MPG, and cost.

[QUOTE]Originally posted by javabeanjava
I suppose if the greenhouse gas theory is correct driving a diesel is not necessarily worse than gas, just causes different problems.[QUOTE]

CO2 is a product of combustion from all carbon based fuels. In my opinion even if CO2 is the cause of the greenhouse gas theory there is absolutely nothing that can be done to reverse it. CO2 is being emitted worldwide and the greenhouse gas theory is a worldwide issue. Every country in the world would have to reduce their CO2 emissions to make a meaningful reduction, it isn't going to happen. For example, China is building coal fired power plants as fast as they can.

There has never been a study that demonstrates how CO2 reductions can reverse the greenhouse gas theory. IMHO the only sensible response to the greenhouse gas theory is to forecast the impacts and learn how to adapt. There will likely be some type of global climate change (man made or otherwise) but there is nothing that can be done to change it in our lifetime or even the next generation. We better learn how to live with it.

 

QUOTE

"In my opinion it is because the diesel industry was very effective in fighting efforts to make diesel cleaner until just a few years ago. That's all history now and by 2007 on road diesel will be as clean as gassers. The big unknown is what will be the impact on diesel performance, maintenance, MPG, and cost."


"Diesels are more popular in Europe because over there they are just as clean as gasoline vehicles, they get more MPG, and fuel costs about $5.00 per gallon."

One last question....If diesels in europe are already as clean as gasoline engines what was the impact on european diesel performance, maintenance and MPG? Aren't these known facts already?

 

Jonesboro hit the nail on the head. The only bad things that Diesels emit more than gasses are particulates, which by most reports are the least of the worries out of a tail pipe. I had a good web page that compared a lab analysis of Diesel to gasoline emissions, but I lost it. Maybe somebody else would have what I'm talking about. (Although for all I know it might have come from Berkeley )

I for one am sick of people asking for Diesel to be as clean as gasoline. I want gasoline cars to put out cleaner emissions than my biodiesel/ SVO burning Diesel! When's that gonna happen?