Are "Cean Diesels" Ready to Join Good Hybrids as a Clean Vehicle Option?

Patricia Monahan, Senior Vehicles Analyst for UCS writing in the HybridBlog says: Honda, Mercedes-Benz, DaimlerChrysler and VW are all planning on selling diesel cars, touting their 20 to 30 percent superior fuel economy over comparable gasoline models. ... A gallon of diesel fuel takes more oil to produce and it produces more greenhouse gases than a gallon of reformulated gasoline (with ethanol). This means you should cut the diesel fuel economy by as much as 15% when comparing it to a gasoline model. ... Diesel cars don't have sophisticated pollution monitors-—like gasoline vehicles do— to catch systems when they fail.  So long-term use and emissions impact is still very much up in the air. In all, there are reasons to be both excited, and wary, about the new diesel cars we'll soon be seeing on the market.

I wonder what the comparison is on biodiesel. With very limited supplies of biodiesel, the use of biodiesel is likely to be limited to areas of the U.S. where there are biodiesel supplies.  Until or unless FT diesel becomes available drivers in the U.S. are largely forced to use petroleum diesel.

Patricia Monahan, Senior Vehicles Analyst for UCS writing in the HybridBlog says: Honda, Mercedes-Benz, DaimlerChrysler and VW are all planning on selling diesel cars, touting their 20 to 30 percent superior fuel economy over comparable gasoline models. ... A gallon of diesel fuel takes more oil to produce and it produces more greenhouse gases than a gallon of reformulated gasoline (with ethanol). This means you should cut the diesel fuel economy by as much as 15% when comparing it to a gasoline model. ... Diesel cars don't have sophisticated pollution monitors-—like gasoline vehicles do— to catch systems when they fail.  So long-term use and emissions impact is still very much up in the air. In all, there are reasons to be both excited, and wary, about the new diesel cars we'll soon be seeing on the market.

I wonder what the comparison is on biodiesel. With very limited supplies of biodiesel, the use of biodiesel is likely to be limited to areas of the U.S. where there are biodiesel supplies.  Until or unless FT diesel becomes available drivers in the U.S. are largely forced to use petroleum diesel.

Comments

[mcr]

Short comment:

One key point is that these may even out the demand - supply issues...

Diversification is a good thing here.

Also the pollution issues (you're correct on) should be solvable given the same levels of investment as those for petrol (gasoline). Including novel particulate monitors and filters for the exhaust systems etc.

Its still early on in this topic... to be able to truely tell the bigger picture...

[Cervus]

My understanding is that diesel is actually less energy intensive to produce because it is a heavier oil. In order to make gasoline from increasingly heavy, sour crude you must use energy intensive hydrocrakers.

Over 50% of European new cars sold are diesels, some of which get fuel mileage comparable to a hybrid without the complexity of an extra drive system. Frankly, I think they're on to something.

[Engineer-Poet]

Odograph's reference puts the well-to-pump efficiency of diesel at 87.9%, gasoline at 82.9% - a substantial advantage in favor of diesel.

[amazingdrx]

Internal combustion at 14% efficiency or fuel cell backup battery electric that can use on average 5 to 10% of the liquid fuel for the same utility and miles driven? That's the vital question.

Not the specific type of liquid fuel. All liquid fuels are either very greenhouse gas emitting, fossil fuelish, and/or like biodiesel or ethanol impossible to produce enough to replace fossil fuels.

Electric vehicles would reduce fuel consumption to levels where fuel cell backup could be powered by algae grown in solar systems. Solar systems mounted on existing buildings and over parking lots, using up no more of our conservation land that naturally sequesters CO 2.

It is important to keep one's eye on the ball in this game of corrupt politics, corporatist market manipulation,war over oil, and technological inovation. The place of humankind here on planet earth depends upon it now.

[Tom Konrad]

Why is it Diesels vs. Hybrids? How about diesel AND hybrid? Throw in a plug-in option and you could probably get 150+ MPG on veggie oil.

[Engineer-Poet]

I get about 40 MPG now.  If PHEV can produce 80% savings, I'd average 200 MPG (or 180 MPG after allowing for the lower energy density of FAME vs. alkanes).

[George]

The toxicity of diesel particulates is now well established. Diesel engines are more expensive than gasoline for a well to wheels efficiency that is only marginally better. Before committing to diesels, I would want to know that they were going to be nearly as clean as other alternatives, and that they would stay that way over the life of the vehicle. Current "clean diesels" are said to emit 5% of the particulates of current diesels. If I have to drive behind one, that's not good enough. If we see anything like European diesel penetration in America, our air will be substantially dirtier than it is today.

[Charles S]

"...get fuel mileage comparable to a hybrid without the complexity of an extra drive system."

It think it is a myth that because diesels are "less complex" that it HAS to be more reliable. Do a search on the web and there are many stories about diesel failures, including new generation of "cleaner" diesels.

Of course there are plenty of stories about great long-lasting diesel engines. I think it's a nice sentiment to think that one is buying a "quality" product. Unfortunately, at this day and age, we no longer value 10-20 years old engines as "good investment" but rather as dated, polluting relics. All the chest-pounding branding such as BlueTec or TDI will mean nothing when the next generation of diesel debuts.

If we truly care about emissions and efficiencies, then we cannot accept poor performance of diesels, even the so-called "clean" diesels for cars. Any "minor" shortcomings of diesels will be multiplied by the hundred thousands, if not millions globally. So saying that diesels are "just as good" as hybrids is just an excuse, not a solution.

There is always a place for diesels in heavy-duty vehicles, and let's keep it that way. Let's reserve the limited, cleaner biofuels for such markets. For people movers such as small cars, let's keep it clean and efficient, and put this diesel vs. hybrid debate to rest.

[Steve]

While at the show i ran across an incredible Diesel Performance company that specializes in diesel performance, and better mileage in any diesel truck. Truly amazing what they can do.