Rebirth of Diesel?

[D'kian]

popular mechanics had an interesting article about mdoern diesel engines for cars. It turns out they get much better milleage than hybrid cars, and consequently they have lower fuel costs, but also that modern diesel cars handle better and have more power than hybrids, on a par with regular gas vehicles in fact.

The article makes a point that Diesels also have lower "greenhouse gas" emissions than hybrids. But the article says the magaznie didn't test for nitrous oxides or particualte matter. Now, CO2 is harmless to people and animals and beneficial for plants. The pollutants contained in gas exhaust, including ozone, sulfur cmpounds, nitrous oxides and particualtes, among others, are not good for people or animals (though not as bad as the enviromentalists would have you believe, either). Notice how the concern lies with a harmless or beneficial byproduct of fuel usage rather than the legitimately harmful ones.

Diesel is also cheaper than gasoline. So even though a Diesel cars costs more to buy, given the lower fuel costs and the high fuel efficiency, it may save you money in the medium term (say 2 to 5 years). As a matter of fact, the company I work for has been acquiring Diesel delivery trucks for that reason. A colleague in the same business is thinking of replacing his delivery fleet with Diesels as well, for the same reasons (plus his fleet is so old it spends too much time in the shop). We have lower fuel bills and the trucks visit the fueling station less frequently (meaning they are operational longer each week).

That's all very good. If they pollute less, so much the better. But the article goes on to note Diesel fuel may rise in price for two reasons. 1) As more people get Diesel cars, the demand goes up and so does the price. 2) The current ethanol gold-rush (which may turn out to be a nother tulip-mania, but that's another topic) requires a lot of Diesel vehicles (tractors, harvesters, trucks, etc), which also increases demand. The writers predict Diesel may rise to a level comparable to gasoline.

Of course it would still be worth it, assuming there are no shortages, because you'd still consume less Diesel than gas.

BTW there's nothign musterious about Diesel's performance. A gallon of Diesel oil contains more energy than a gallon of gas. Diesel can also be compressed more, meaning it can extract more power per stroke of the engine than gas can.

Finally the thought arises: If Diesel is so good and so efficient, why not make Diesel hybrids? I suppose they'd then achieve over a hundred miles per gallon of fuel.

[A.West]

Modern diesel engines offer some real advantages, but are also generally more expensive to produce than gas engines. More metal, a turbocharger, and special emissions equipment all add to the cost. When fuel is expensive, people can still benefit from paying an extra $1000 or more per car, over time. But some people simply can't afford to buy a car at a higher price point. A diesel hybrid would boost efficiency, and it would also boost the up-front costs, to a degree that may never be recovered from long-term fuel savings.

[D'kian]

Modern diesel engines offer some real advantages, but are also generally more expensive to produce than gas engines. More metal, a turbocharger, and special emissions equipment all add to the cost. When fuel is expensive, people can still benefit from paying an extra $1000 or more per car, over time. But some people simply can't afford to buy a car at a higher price point. A diesel hybrid would boost efficiency, and it would also boost the up-front costs, to a degree that may never be recovered from long-term fuel savings.

For instance, I wouldn't buy a Diesel car because my employer pays my fuel expenses. I'm sure the comapny would pay for Diesel, too, but the station we've a contract with is not near enough to the office. Nor would I care to spend $2,000 more on a car if I were to get no savings from it.

Another disadvantage is that fewer stations serve Diesel. In the US the figure is about 50%, most of them located on highways. Here in Mexico I know a few, but most stations simply don't carry it. That's logical as there isn't much demand for Diesel in most cities. So if you ahve to drive 10 extra miles to fill up, you may reconsider even if you save money.

[KendallJ]

Of course it would still be worth it, assuming there are no shortages, because you'd still consume less Diesel than gas.

BTW there's nothign musterious about Diesel's performance. A gallon of Diesel oil contains more energy than a gallon of gas. Diesel can also be compressed more, meaning it can extract more power per stroke of the engine than gas can.

D'kian, I'm not sure the point of your post, but it makes the glaring mistake of assuming the environmentalists premise.

Look at your mistake above. If there is no magic in diesels performance, simply that it contains more energy per unit than gas, then the previous statement that diesel is somehow more "worth it" is incorrect. There is no magic. Driving around consumes the same amount of energy so you're still consuming the same amount of energy whether you use diesel or gas. Whether than energy is contained in a gallon of gas or a 1/2 gallon of diesel is of no importance. What is worth it exactly?

[D'kian]

Look at your mistake above. If there is no magic in diesels performance, simply that it contains more energy per unit than gas, then the previous statement that diesel is somehow more "worth it" is incorrect. There is no magic. Driving around consumes the same amount of energy so you're still consuming the same amount of energy whether you use diesel or gas. Whether than energy is contained in a gallon of gas or a 1/2 gallon of diesel is of no importance. What is worth it exactly?

If Diesel and gas both cost the same, say $2.50 per gallon, then Diesel would still be the more economical choice because you'd consume less fuel and therefore pay less money.

Yes, the energy is the same. A 1,500 lb car requires X amount of energy to move 1 mile regardless of the fuel it uses. But how much fuel it consumes depends on the fuel and the type of engine.

I'm more interested in the economics of the situation. As I said, the company I work for is acquiring Diesel trucks. Last month I rode along in one to deliver samples. I was amazed we went over 70 miles round trip and used up very little fuel. The same trip in my car, I've made it many times, consumes about 12 liters of gas (say a little under 3 gallons). According to the article on Popular Mechanics a Diesel car would have used up a gallon or less (about four liters). That's a savings of 66%

[KendallJ]

If Diesel and gas both cost the same, say $2.50 per gallon, then Diesel would still be the more economical choice because you'd consume less fuel and therefore pay less money.

Except that this "if" is using an effect as an input. If all other things were equal and diesel had twice the energy as gas, then they wouldn't cost the same. If they don't cost the same per unit energy (which is what fuel value is) then there must be other differences that outweigh the energy value.

That is the economics of the situation. I think the other thing that you want to consider is that gasoline and diesel supplies are related. That is, they are both distillates from the refining of crude oil. That, and the other uses for oils of that nature may also directly affect supply dynamics (and pricing)

[-archimedes-]

I'm just going to borrow an earlier post of mine from a different thread ("Hydrogen Cars") to express my impressions on the subject matter here, i.e.:

I'd like to respond to your assertions with two(2) words, i.e., "particulate matter".

You see, diesel is as diesel does, my momma always say-id. And the simple facts of the matter are that for the same load and engine conditions, diesel engines spew out 100 times more sooty particles than gasoline engines. As a result, diesel engines account for an estimated 26 percent of the total hazardous particulate pollution (PM10) from fuel combustion sources in our air, and 66 percent of the particulate pollution from on-road sources. Diesel engines also produce nearly 20 percent of the total nitrogen oxides (NOx) in outdoor air and 26 percent of the total NOx from on-road sources. Nitrogen oxides are a major contributor to ozone production and smog. http://www.lungusa.org/site/pp.asp?c=dvLUK9O0E&b=36089 "

This, of course, is all to say that "diesel" is not the way.

Edited December 31, 2007 by -archimedes-

[-archimedes-]

Also, in addition to the points of interest pointed out by KendallJ, as they relate to "...the economics of the situation", I'd also like to point out the "economics" of the increased costs of health care costs/medical services that would be prompted by widespread use of diesel as a means of fueling our vehicles as the combustion of diesel fuel produces twice to three times the amount of harmful/deadly environmental/atmospheric emissions as gasoline/petrol-based fuels, as I've reiterated above.