The Truth About Diesels (truthaboutcars.com)
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The Truth About Diesels (truthaboutcars.com)
http://www.thetruthaboutcars.com/?p=4039
By Paul Niedermeyer
July 2, 2007
No wonder the Germans are so gung-ho on sending their diesels across the pond. Europe’s two-decade long diesel-keg party has been crashed by a new generation of super-efficient, clean and cheaper gasoline engines. A royal diesel-overproduction hang-over is inevitable. The Germans’ morning-after solution: send the stinky leftovers to enthusiastic Yanks waiting with open arms, who’ve conveniently forgotten their killer hangover from the last US diesel orgy.
In 1892, an experimental ammonia engine literally blew up in engineer Rudolph Diesel's face. Laid-up in a hospital bed, he pored over Nicolaus Otto’s pioneering work on the internal combustion engine. Diesel identified its weakness.
Diesel tumbled to the fact that the Otto engine’s efficiency was intrinsically compromised by the fact that it mixed fuel with air prior to compression. Too much compression resulted in uncontrolled pre-detonation. Diesel’s solution: inject fuel separately from the air to allow super-high compression and eliminating the need for a throttle (reducing pumping losses). Diesel's engine was roughly 30% more efficient than Otto's.
In 1989, VW/Audi ushered in the modern direct-injection (TDI) diesel. The group's oil burning powerplant set a high-water mark in the diesel’s long development. With Europe’s high fuel costs, the more expensive (yet efficient) diesel engine could now pay for itself quite easily. The calculation triggered Europe's diesel-boom, resulting in a 50 percent market share vs. gasoline-engined propulsion.
But Europeans have been paying a price (other than at the pumps): particulate emissions (Particulate Matter, or “PM”) and NOx pollution. Many European cities have serious particulate and diesel odor problems. Several European cities impose restrictions on diesels during PM alerts.
The new generation of “clean(er)” diesels that meet the US Tier2 bin5 standards cut PM emissions substantially, but not completely. Already, there are warnings that PM from “clean” diesels still poses a significant health risk.
The diesels coming our way carry several other penalties, especially versus the gas hybrid. The complicated and expensive NOx catalysts and urea injection schemes (“BlueTec”) cut efficiency by five percent. Meanwhile, the next Prius is projected to be 15 to 20 percent more efficient. And Toyota is bringing down hybrid production costs.
The diesel vs. hybrid mileage/cost gap widens… further. And the “clean” diesel’s just-barely compliant emissions still can’t touch the gas-hybrid’s practically breathable exhaust.
Then there's the elephant in the room: global warming. Clearly, the political winds are blowing against CO2. Diesel fuel has higher carbon content, resulting in 17 percent more CO2 per gallon of fuel burned than gasoline. With the diesel’s efficiency superiority down to 25 percent, a “clean” diesel emits only 13 percent less CO2 than yesterday’s gas engine. And that small gap is… wait… gone.
While the diesel’s efficiency peaked in 1989, and lost 5 percent to PM cleansing, gas engine development is on a roll. Engineers are systematically tackling all the inherent deficiencies that Diesel identified in his hospital bed. (No wonder Rudolf was considered paranoid; maybe he suspected that eventually the Otto engine would catch up.)
A farrago of new gas-engine technologies has converged, which Europeans have been quick to embrace. VW’s 1.4-liter 170hp TSI gas engine is a perfect example of the trend. The TSI starts off with the help of a supercharger (no turbo-lag), and then switches to turbocharging (no parasitic losses). With diesel-like torque and direct injection, it’s the best of both worlds.
A CO2 output comparison with two other similar-output VW engines is telling. Their 170 horse 1.4-liter TSI produces 174g/kms of CO2. Their 150hp 2.5-liter five cylinder engine (US Rabbit only) emits 240g/km. And their 170hp 2.0-liter TDI diesel (not US compliant) produces 160g/km.
American Rabbit drivers are paying a whopping 38 percent efficiency penalty compared to the Euro-Golf TSI, as well as giving up gobs of torque and twenty horsepower. If VW’s 170hp TDI were “cleansed” to T2b5 standards, its CO2 output would be no better then the gasoline TSI.
And that’s just the jumping-off point. Start-stop technology, full valve control, and stratified direct-injection offer anywhere from 10 to 25 percent further improvement potential. Combine these goodies with mild-hybrid assist/regeneration, and the diesel party’s kaput. No wonder the Germans are all hard at work on mild-hybrid technology. It’s their best shot to keep up with Toyota’s CO2 meister, the Prius (102g/km).
A study by the consulting firm AT Kearny confirms the diesel's demise. It predicts that only 25 percent of Europeans will find diesels an attractive economic proposition by 2020.
Have Rudolf Diesel’s paranoid nightmares come true? Not totally. Diesels are a welcome mix to the party for larger vehicles that spend a lot of time on the open road. Count on GM’s new 4.5-liter “baby” Duramax diesel to be more popular with the light-truck crowd than the gas hybrid option. But when it comes to smaller vehicles, the numbers just don’t add up.
Although Rudolf Diesel’s engine WAS intrinsically more efficient, it turns out that Otto’s engine is a lot more clever at learning new tricks.
July 2, 2007
No wonder the Germans are so gung-ho on sending their diesels across the pond. Europe’s two-decade long diesel-keg party has been crashed by a new generation of super-efficient, clean and cheaper gasoline engines. A royal diesel-overproduction hang-over is inevitable. The Germans’ morning-after solution: send the stinky leftovers to enthusiastic Yanks waiting with open arms, who’ve conveniently forgotten their killer hangover from the last US diesel orgy.
In 1892, an experimental ammonia engine literally blew up in engineer Rudolph Diesel's face. Laid-up in a hospital bed, he pored over Nicolaus Otto’s pioneering work on the internal combustion engine. Diesel identified its weakness.
Diesel tumbled to the fact that the Otto engine’s efficiency was intrinsically compromised by the fact that it mixed fuel with air prior to compression. Too much compression resulted in uncontrolled pre-detonation. Diesel’s solution: inject fuel separately from the air to allow super-high compression and eliminating the need for a throttle (reducing pumping losses). Diesel's engine was roughly 30% more efficient than Otto's.
In 1989, VW/Audi ushered in the modern direct-injection (TDI) diesel. The group's oil burning powerplant set a high-water mark in the diesel’s long development. With Europe’s high fuel costs, the more expensive (yet efficient) diesel engine could now pay for itself quite easily. The calculation triggered Europe's diesel-boom, resulting in a 50 percent market share vs. gasoline-engined propulsion.
But Europeans have been paying a price (other than at the pumps): particulate emissions (Particulate Matter, or “PM”) and NOx pollution. Many European cities have serious particulate and diesel odor problems. Several European cities impose restrictions on diesels during PM alerts.
The new generation of “clean(er)” diesels that meet the US Tier2 bin5 standards cut PM emissions substantially, but not completely. Already, there are warnings that PM from “clean” diesels still poses a significant health risk.
The diesels coming our way carry several other penalties, especially versus the gas hybrid. The complicated and expensive NOx catalysts and urea injection schemes (“BlueTec”) cut efficiency by five percent. Meanwhile, the next Prius is projected to be 15 to 20 percent more efficient. And Toyota is bringing down hybrid production costs.
The diesel vs. hybrid mileage/cost gap widens… further. And the “clean” diesel’s just-barely compliant emissions still can’t touch the gas-hybrid’s practically breathable exhaust.
Then there's the elephant in the room: global warming. Clearly, the political winds are blowing against CO2. Diesel fuel has higher carbon content, resulting in 17 percent more CO2 per gallon of fuel burned than gasoline. With the diesel’s efficiency superiority down to 25 percent, a “clean” diesel emits only 13 percent less CO2 than yesterday’s gas engine. And that small gap is… wait… gone.
While the diesel’s efficiency peaked in 1989, and lost 5 percent to PM cleansing, gas engine development is on a roll. Engineers are systematically tackling all the inherent deficiencies that Diesel identified in his hospital bed. (No wonder Rudolf was considered paranoid; maybe he suspected that eventually the Otto engine would catch up.)
A farrago of new gas-engine technologies has converged, which Europeans have been quick to embrace. VW’s 1.4-liter 170hp TSI gas engine is a perfect example of the trend. The TSI starts off with the help of a supercharger (no turbo-lag), and then switches to turbocharging (no parasitic losses). With diesel-like torque and direct injection, it’s the best of both worlds.
A CO2 output comparison with two other similar-output VW engines is telling. Their 170 horse 1.4-liter TSI produces 174g/kms of CO2. Their 150hp 2.5-liter five cylinder engine (US Rabbit only) emits 240g/km. And their 170hp 2.0-liter TDI diesel (not US compliant) produces 160g/km.
American Rabbit drivers are paying a whopping 38 percent efficiency penalty compared to the Euro-Golf TSI, as well as giving up gobs of torque and twenty horsepower. If VW’s 170hp TDI were “cleansed” to T2b5 standards, its CO2 output would be no better then the gasoline TSI.
And that’s just the jumping-off point. Start-stop technology, full valve control, and stratified direct-injection offer anywhere from 10 to 25 percent further improvement potential. Combine these goodies with mild-hybrid assist/regeneration, and the diesel party’s kaput. No wonder the Germans are all hard at work on mild-hybrid technology. It’s their best shot to keep up with Toyota’s CO2 meister, the Prius (102g/km).
A study by the consulting firm AT Kearny confirms the diesel's demise. It predicts that only 25 percent of Europeans will find diesels an attractive economic proposition by 2020.
Have Rudolf Diesel’s paranoid nightmares come true? Not totally. Diesels are a welcome mix to the party for larger vehicles that spend a lot of time on the open road. Count on GM’s new 4.5-liter “baby” Duramax diesel to be more popular with the light-truck crowd than the gas hybrid option. But when it comes to smaller vehicles, the numbers just don’t add up.
Although Rudolf Diesel’s engine WAS intrinsically more efficient, it turns out that Otto’s engine is a lot more clever at learning new tricks.
Lexus Champion
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From: FL
Europe's particulate problem (is it any worse health threat than California's smog problem?) perhaps won't be relevant when the new, cleaner diesels start finding their way onto American shores (?).
We'll have to wait and see if Niedermeyer's points end up being relevant. I'd prefer to hear the truth about diesels from someone that doesn't have such an obvious slant against the diesel technology (referring to Paul Niedermeyer). I doubt that he could been any more sarcastic when he wrote that article. For me, that results in taking the entire list of "facts" claimed in the article with a grain of salt.
We'll have to wait and see if Niedermeyer's points end up being relevant. I'd prefer to hear the truth about diesels from someone that doesn't have such an obvious slant against the diesel technology (referring to Paul Niedermeyer). I doubt that he could been any more sarcastic when he wrote that article. For me, that results in taking the entire list of "facts" claimed in the article with a grain of salt.
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CL Community Team
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Hybrids are stepping stones to eventually make electric cars that do not consume fossil fuels at all. They will work will hydrogen as well eventually. If you don't start somewhere, newer, better technologies will never be developed. That's the "FORREST" we are looking at.
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The article is a bit slanted against diesels though Autocar tested the 1.4 litre 170bhp Golf (Rabbit) and were quite impressed:
http://www.autocar.co.uk/CarReviews/...170-GT/217183/
Hybrids offer a good solution in cities where diesel particulates can be a problem but they cannot match the mpg you get from a diesel on the highway. Much of the stop/start and regenerative breaking technology can also be applied to diesels giving real world mpgs that break the 60mpg average barrier. Perhaps the future is small, efficient diesels matched with a hybrid powertrain.
http://www.autocar.co.uk/CarReviews/...170-GT/217183/
Hybrids offer a good solution in cities where diesel particulates can be a problem but they cannot match the mpg you get from a diesel on the highway. Much of the stop/start and regenerative breaking technology can also be applied to diesels giving real world mpgs that break the 60mpg average barrier. Perhaps the future is small, efficient diesels matched with a hybrid powertrain.
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Hybrids are stepping stones to eventually make electric cars that do not consume fossil fuels at all. They will work will hydrogen as well eventually. If you don't start somewhere, newer, better technologies will never be developed. That's the "FORREST" we are looking at.
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From: FL
Hybrids are stepping stones to eventually make electric cars that do not consume fossil fuels at all. They will work will hydrogen as well eventually. If you don't start somewhere, newer, better technologies will never be developed. That's the "FORREST" we are looking at.
I see the diesel vs. hybrid debate as being the same thing. Diesels are the much simpler solution, and result in equally great gas mileage. If you can use 5 moving parts to do some [task], why would you use 8 moving parts to do the same [task]? There are reasons, and I know what they are. Some legitimate, some not.
And each technology has its own list of negatives. But if I had to choose between making diesel emit fewer particulates, and making hybrid technology far less complex and energy-intensive on the development/production side of things, I'd choose the diesel problem.
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Diesel is still a fossil fuel, so it won't solve anything in the real long term. Most of our new technologies in any field is more complex than the old, that doesn't mean thay cannot be viable in the long term.
Abacus used to beat calculators too in calculations, but that didn't stop us from developing faster & faster computers that we have today, we wouldn't have worked on them had we belief computing machines are too much more complex than an abacus & quit working on developing & refining them, & our computing powers wouldn't be at what we are today.
We can debate about whether fossil fuels will run out in 50 or 100 years, but the fact is, it eventually will, & if you continue to rely on them without working on alternative technologies, they will become more scarce over the long run & get more & more expensive, since the world's demand will continue skyrocketing. The sooner we can decrease our reliance of them the better.
Diesel hybrids already exist, if they can make them in a cost effective way, more will be available, but they are still not a long term solution.
Abacus used to beat calculators too in calculations, but that didn't stop us from developing faster & faster computers that we have today, we wouldn't have worked on them had we belief computing machines are too much more complex than an abacus & quit working on developing & refining them, & our computing powers wouldn't be at what we are today.
We can debate about whether fossil fuels will run out in 50 or 100 years, but the fact is, it eventually will, & if you continue to rely on them without working on alternative technologies, they will become more scarce over the long run & get more & more expensive, since the world's demand will continue skyrocketing. The sooner we can decrease our reliance of them the better.
Diesel hybrids already exist, if they can make them in a cost effective way, more will be available, but they are still not a long term solution.
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Abacus used to beat calculators too in calculations, but that didn't stop us from developing faster & faster computers that we have today, we wouldn't have worked on them had we belief computing machines are too much more complex than an abacus & quit working on developing & refining them, & our computing powers wouldn't be at what we are today.
How is hybrid technology helping us to develop future alternative methods of propulsion? By putting a bandaid on the gas engine? If there was a good solution out there, we'd already be developing it. And we probably are(?).
Until someone can figure out how to make batteries that will hold a charge long enough to move a car for 300+ miles, and fully recharge again at a household outlet within a few minutes, we're stuck with what we have available. Producing dealer lots full of hybrid cars isn't going to help you develop longer lasting batteries.
I'll keep contending that the best solution for now, is the one that's the most simple. Same end result, less energy burned in getting to that point.
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Fossil fuels? thats the next generations problem. When i reincarnate hopefully we'll have figured out cold fusion and flux capasitors will be avalible at radio shack, 1.21 JIGGAWATTS BABY!!! 
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If you are concerned about the environment then hybrids are probably a better answer - though they do cost more to buy and maintain and require recycling the battery to be truly environmentally conscious.
I think most people, in reality, are more concerned with reducing their expenditures on gas. And diesels are absolutely a better economical choice in that regard.
Not to mention if the new round of diesel cars meets the government's new emissions standards, they'll be exhaling quite cleanly.
We're to the point that new cars just don't make much if any impact on the quality of our air. Compare the emissions output of a 15 year old Honda civic or Toyota corolla to the emissions output of a brand new Hummer H2. The H2 puts out far less emissions despite being compared to a car that most environmentalists would ignorantly probably "approve" of.
I think most people, in reality, are more concerned with reducing their expenditures on gas. And diesels are absolutely a better economical choice in that regard.
Not to mention if the new round of diesel cars meets the government's new emissions standards, they'll be exhaling quite cleanly.
We're to the point that new cars just don't make much if any impact on the quality of our air. Compare the emissions output of a 15 year old Honda civic or Toyota corolla to the emissions output of a brand new Hummer H2. The H2 puts out far less emissions despite being compared to a car that most environmentalists would ignorantly probably "approve" of.
great post. Hybrids are the bandaids. They're heavy, complex, and only really offer benefits in 2 ways - city stop/start driving (better economy/lower emissions), and quiet starts.
I'll keep contending that the best solution for now, is the one that's the most simple. Same end result, less energy burned in getting to that point.
a prius almost ran me over once because i did not hear it coming at night.