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Old June 21st 05, 07:38 PM
Dori A Schmetterling
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A number of your points are US-centric, others contain sweeping
generalisations, others are interesting and instructive.

See below.

DAS
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"MoPar Man" > wrote in message
...
> Dori A Schmetterling wrote:
>
>> Much better fuel economy, esp in city driving. That's why even
>> in the UK, which has been traditionally anti-diesel, the diesel
>> car is on the rapid rise, despite the fact that the price of the
>> fuel is about the same as petrol.

>
> Diesel engine costs more as an option:
>
> "Volkswagen's midsize 2005 Passat diesel sedan has a starting MSRP of
> $23,360. This compares with $22,070 for a comparable gasoline Passat
> model." (1)


FROM DAS: Not with Mercedes, and differentials are coming down. Can't
speak about US.

>
> Prohibited by law:
>
> "Diesel models are limited in their availability in the U.S. because
> five states-California, New York, Massachusetts, Maine and Vermont
> prohibit their sale due to emission restrictions." (1)


FROM DAS: A US problem only.

>
> But produce more torque:
>
> "Yet the 2.0-liter four-cylinder engine in the Passat TDI, as the
> diesel versions are called, puts out an amazing 247 lb-ft of torque at
> a low 1900 rpm vs. the 166 lb-ft of torque at 1950 rpm in the
> 1.8-liter four-cylinder gasoline engine in the base Passat sedan." (1)
>
> Get better gas milage:
>
> "Thanks to its higher energy content and its efficient combustion
> process, diesel performance enables cars to travel at least 30%
> farther on a gallon of fuel than comparable gasoline models." (2)
>
> But the savings will take time to pay-back the initial increased cost:


FROM DAS: I agree. Not everyone thinks it through (where it applies).

[...]

> And, not every urban filling station
> has a diesel pump.


FROM DAS: US-centric. In Europe it's ubiquitous.

>
> And they are noisy (more than a comparible gas engine).


FROM DAS: True, but difference is getting less. Inside the car it is hard
to tell.

>
> Diesel is more popular in Europe because it is taxed less than
> gasoline:
>
> "The demand for diesel in Europe is fueled by the high cost of
> gasoline. (Unequal taxation of the two fuels results in diesel costing
> about one dollar less per gallon in most European countries.)" (2)


FROM DAS: As I said, in Britain diesel costs about the same as petrol.
However, in other countries there are varying differentials. In some (all?)
there is 'compensation' by extra taxes on the cars, either at purchase or on
the road-usage tax. I suppose it's a way of helping commercial traffic
without giving the same advantage to private transport.

>
> It takes more oil to make a gallon of diesel than for gasoline, so the
> relative efficiencies of diesel and the costs to consumer due to
> taxation really make the attraction of diesel questionable:
>
> "It should be noted, however, that it takes about 25% more oil to make
> a gallon of diesel fuel than a gallon of gasoline, so we should really
> look at how a vehicle does on fuel efficiency in terms of "oil
> equivalents." Thus, we need to adjust the mileage claims for diesel
> vehicles downward by about 20% when comparing them to gasoline-powered
> vehicles." (2)


FROM DAS: Very instructive. I wonder what the real-world situation is,
i.e. the marginal cost of making diesel in the general refining process.

>
> Although diesel engines generate less carbon dioxide (only because of
> their slightly better fuel economy), they put out more smog-forming
> pollutants than gasoline engines:
>
> "when it comes to smog-forming pollutants and toxic particulate
> matter, also known as soot, today's diesels are still a lot dirtier
> than the average gasoline car." (2)


FROM DAS: True, but modern engines have increasingly efficient particulate
filters such that the difference is not so great any more and shrinking.

>
> It will take more effort and cost than it's worth to make diesel
> cleaner than gasoline:


FROM DAS: Not so in the real world. The forthcoming filters on Mercedes
(and probably other) cars should be very interesting. Everyone will follow
suit in the end.

>
> "To meet the tougher pollution standards, high-tech diesel engines
> need low-sulfur diesel fuel. Unfortunately, US Department of Energy
> modeling has shown this fuel to be more oil and carbon-intensive than
> reformulated gasoline. Making a gallon of diesel fuel requires 25%
> more oil and emits 17% more heat-trapping greenhouse gases than
> gasoline reformulated with MTBE. Similarly, diesel requires 17% more
> oil and emits 18% more heat-trapping gases than gasoline reformulated
> with ethanol. This means that diesel fuel's advantages from its higher
> per-gallon energy content and better performance on greenhouse gases
> are partially offset by the impact of diesel's fuel-production
> process."


FROM DAS: As above.

What are Ann Job's credentials? Well-known motoring journalist or stringer
who happens to be doing an article on a topical motoring subject? (Sorry, I
don't know who she is.)
>
> (1)
> http://autos.msn.com/advice/article....tentid=4022630
>
> (2)
> http://www.grinningplanet.com/2005/0...ne-article.htm


FROM DAS: Something about the article makes me think it takes a US-centric
view and does not take European developments fully into account, e.g. modern
soot filters.


>
> For more info, see he
>
> The Diesel Dilemma
> Diesel's Role in the Race for Clean Cars
>
> http://www.ucsusa.org/clean_vehicles...fm?pageID=1307


FROM DAS: It is sometimes a dilema but the article isn't entirely accurate,
e.g the comment about low-tax diesel fuel. For a Brit to take his/her car
to, say, the Netherlands and fill up with much cheaper diesel is great fun
while it lasts, bu the locals pay in other ways, as mentioned above.

For commercial traffic it is, apparently, no contest. All heavy goods
vehicles run on diesels. And they are all turbocharged, of course, hence
the small engine compartments. Well, passenger cars have turbodiesels as
well.


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