This new govt will be just like it was last time it was in, commit to every protocol, spend every cent on everything, say sorry to the stolen generation when we should be sorry for not taking a pile more out of squalor right now. This govt got in because a pile of current voters didn't have houses or creditcards last time they were in and they all have a job now if they want one. Kyoto is a huge joke it ties modernised countrys already striving for economical reduction in polution so that our products are unviable. What do we do? buy the products from up and comming countrys that are destroying the environment. As for scientists theyre now saying electricity from turbines in dams on rivers produce too much greenhouse gas what a lot of BS

Only after you have explained to me why you think it has less fuel economy ?

That is more the result of diesel having a higher energy content per liter (volume) then gasoline ; not that the diesel engine is so much more efficient in energy conversion (although it is a little more efficient). On the other hand diesel also weights more. It is very interesting to note that the 18% higher energy content of Diesel is mirrored by it also weighting 18% more per given volume.


But even more dependable sources are a little bit confused (see the second paragraph)

From wikipedia : http://en.wikipedia.org/wiki/Diesel

The density of petroleum diesel is about 850 grams per litre whereas petrol (American English: gasoline) has a density of about 720 g/L, about 15% less. When burnt, diesel typically releases about 40.9 megajoules (MJ) per litre, whereas gasoline releases 34.8 MJ/L, about 15% less. Diesel is generally simpler to refine from petroleum than gasoline and often costs less ... Also, due to its high level of pollutants, diesel fuel must undergo additional filtration which contributes to a sometimes higher cost. In many parts of the United States and throughout the whole of the UK, diesel is higher priced than petrol.[1] Reasons for higher priced diesel include the shutdown of some refineries in the Gulf of Mexico, and the switch to ultra-low sulfur diesel (ULSD), which causes infrastructural complications.[2]

Diesel-powered cars generally have a better fuel economy than equivalent gasoline engines and produce less greenhouse gas pollution. This greater fuel economy is due to the higher energy per-litre content of diesel fuel and also to the intrinsic efficiency of the diesel engine. While diesel's 15% higher density results in 15% higher greenhouse gas emissions per litre compared to gasoline,[3] the 20–40% better fuel economy achieved by modern diesel-engined automobiles offsets the higher-per-liter emissions of greenhouse gases, resulting in significantly lower carbon dioxide emissions per kilometre.[4][5]


******


First they define fuel economy as per liter of fuel, which will get the author lose his engineering title if he ever tries to pass it as energy conversion efficiency in any scientific publication. Still, a common reader will definate equate the two and thus be errornously informed. Then they produce another gem. Then they say :

"... the 20–40% better fuel economy achieved by modern diesel-engined automobiles offsets ... "

So first we need to subtract the 15% better fuel economy (as they define it) due to the higher energy content per volume. So we end up with the Diesel engine being 5% to 25% more energy conversion efficient then a gasoline engine which is typically about 20-25% in non stationary operation. Of course this means that a diesel engine will have the following efficiency range in stationary operation : 105%*20% to 125%*25% = 21% to 32%

I know that their "20–40% better fuel economy" sounds alot better (in marketing) but the real SCIENTIFICALLY sound numbers (- energy conversion efficiency) are only 21%-32% for Diesel compared to 20%-25% for gasoline. A difference indeed, but not a huge difference.

I think Hybrid-cars get better ratios then both, mostly because in that setup the engine can be run stationary which will be more efficient still. Even better would be a practical fuel cel setup as that totally circumvents the thermodynamic processes and heat loses that are implicit in combustion engines. As a result a fuel cel is not limited to the max theoretical Carnot energy conversion efficiency of 55%-65%. As a result the practical efficiency can be much higher as well. I had expected a practical fuel cet setup by now but something is holding it up.

Wouter

Trucks may be different but, in cars, in the USA, diesel doesn't make sense economically (bottom line). A (~) 15 to 20% boost in mpg is offset by the 15 to 20% higher price of the fuel. Then look at who offers diesel autos, it's Volkswagon, unless of course you'd like a VW. In the US the highest priced auto, maintenance wise, is anything European. Doesn't make fiscal sense to own diesel. My neighbor has a diesel Passat...very nice car, I had to ask what the TDI stood for! I'll stick with second hand, Pacific rim, gas powered for now. Regardless of effect on the planet, I'm moving in what gets me around in the most economical and expedient fashion. I wont ride the bicycle to the market on Saturday morning because the car will get me there and back faster giving me more time to do what I want (sail maybe?).

Call me very lucky, I have a choice, that's were I suppose a lot of us get rubbed the wrong way. Maybe when I retire I'll ride the bicycle to the market. Maybe when I retire it wont be as important to shave a few hours off the regatta commute and I wont mash the gas pedal to the floor at every chance. Then again, maybe I'll be that old man putzing around in that 60's supercar that gets 8 mpg, that I may have to pour lead additive in the tank to get it to run proper. I don't see the majority of Americans wantingly wasting fuel (except for maybe the occasional Karl <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />) we just want to have a choice.

http://autoshow.autos.msn.com/autoshow/LA2007/Article.aspx?cp-documentid=5729898

Just for you Karl.

22 mpg on the highway = 9.4 km/liter

That is pretty unimpressive in absolute sense.

All larger EU and Jananese family cars get at least that mileage without being hybrid or anything. But of course it is much easier to get the town market on sunday in a vehical that is the size and weight of a Patton Tank. Honestly I have no idea how we in Europe and Japan can survive like this.

Basically all technological breakthroughs that many hope for are and will be used by US drivers to drive even bigger and heavier cars, leaving the net gains at zero ! Like that we will be getting nowhere.

Wouter

That's a 30% improvement! We should hit $4/gallon within 18 months (if not sooner). I can already see fewer SUVs on the road here.

The market has spoken! Price is going up, straight up!

Your math isn't totally accurate, and it's just recently that your argument could even be entertained. Even with your faulty math it looks like it's an economic wash. And what type of cars are we talking about comparing?

Only in the last 6 months has diesel cost more than gas. Why is that, it's less refined? (There's the scam!) And they don't add any oxygenate like MTBE. That crap is toxic and is in the flesh of every fish you eat.

Just 2 years ago I was paying $1.65 per gal for diesel and gas was $2.30 +or-. Now diesel here is $3.69 and gas is $3.58. Just filled up with biodiesel at $3.25 over at Austin Biofuels. And I get 45 to 50 MPG. Do the math for me, I'm too lazy.

kansas city gas prices proof of TODAY, not two years ago.

Math for dummies
$2.77/$3.29= 16%
$3.29/$2.77= 19%
figured both ways (depends on how soulcats cook their numbers)

2005 Passat gas 4cylinder 2005 Passat diesel 4 cylinder Think those are flipped, used the combined MPG
22mpg/27mpg= 19%
27mpg/22mpg= 23%

You busted me, I'm at fault, if we average these two figures and balance the book cooking we come up with 21% and 17.5% Excuse me I'm way off in the weeds with these FACTS.

Go to edmunds online and compare "true cost to own" on a (for instance) 2005 Passat, gas and diesel version. You'll find the diesel will cost $1,406 MORE to own over a five year period. Obviously skewed numbers and fuzzy math.

Why did I even waste my time?

Your specific example sort of works out. That's why I asked what cars you were comparing. What if I generalized and plugged the VW Lupo into your formula? It gets over 80mpg on a turbocharged, electronically controlled diesel.

In your first post you generalized diesel:



Any 'dummy' can take apples and compare them to oranges and come up with the desired "math for dummies".

My 2001 Jetta gets 45 -55 mpg all the time, averaging around 50. That's no skewed apples to oranges argument. It has cost me no more than a regular Jetta to own.

To make it fair pick another mid sized sedan, and compare it with the numbers above. If you're talking strictly monetary bottom line, then it's not a huge amount better. I bought my car to run strictly on biodiesel and straight veg oil, which is about an 85% reduction in hydrocarbon emissions. My personal bottom line. And I try to support the troops by not funding terrorists. Plug those variables into your formula.

Weird math ... Not convinced.

Add a stickshift on these and you get 10% at the minimum better mileage.

Because I get 20mpg, and he gets 15mpg running around empty. Throw heavy trailer on and the gap gets bigger.

Here is a report by Dr. R M Carter, from the Marine Geophysical Laboratory, James Cook University, entitled
The Myth of Dangerous Human-Caused Climate Change Very good read.

We have already established that a gallon of gasoline can not be compared to a gallon of diesel as both have different energy contents. Apples and oranges.

We must first equalize both energy inputs when analysing the (conversion) efficiency of the two engines. Looking at volumes (gallons) is not doing that.

But what am I doing here ? I've explained this several times already in my other posts and you still don't get it. Why would you understand it now ?

Wouter

I understand what you are saying wouter. It's just not how people, (me), percieve buying fuel for there vehicle. We don't buy it by the BTU, we buy it by the gallon, or liter in your case. And when we use it we do it as a mile per gallon. Or k/l, whatever.

"Communism (has been) replaced by ambitious environmentalism" Hoo-ya, good stuff eh?

What about us engineer/science people that work in environmental air emissions and DON'T believe??? is it hard for me?? <img src="http://www.catsailor.com/forums/images/graemlins/wink.gif" alt="" />

www.junkscience.com

What about us engineer/science people that work in environmental air emissions and DON'T believe??? is it hard for me?? <img src="http://www.catsailor.com/forums/images/graemlins/wink.gif" alt="" />

Agree, having spent 40 years in a related field.

http://macnelly.com/
select the strip Dec.3 <img src="http://www.catsailor.com/forums/images/graemlins/blush.gif" alt="" />

Timbo you say that the ice caps are melting, did you read that Ice thicknesses are increasing both on Greenland and in Antarctica. Just wondering as you and many others keep missing this point.