99 MPG!!! (PAH)

Kal Row

and it will be a lot less painful at the pump - we are a comfort driven society - us wetheads know this better than anyone else, that's why the diesel electric is not a good fit, since americans need the acceleration/speed you get out of a gas - also the constant starting and stopping of the fossil engine is not a good fit for diesel -

as a recreational pilot on the other hand, the diesel is perfect, and i am glad that they are finally offering diesels for light aircraft that run on jet fuel, especially since the 100LowLeadOctane we are using now, is becoming more expensive and harder to get every day,

Dave Yates (PAH)

Hybrid electric-gas car

Our oldest son had to rent a car while his was being repaired. He was rear-ended on the interstate by an inattentive driver who failed to see traffic was stopped. No injuries. The car he rented was a hybrid electric motor - gas motor thing that included a mileage per gallon indicator. Once you finish accelerating, the electric motor takes over unless the batteries are discharged too far, in which case the gas motor runs. In-town mileage? Shows as 99 MPG when the electric takes over! And, according to John, even at 100 MPH the electric motor takes over as soon as you level off on the throttle.

The times they are a-changing.

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Tony_8

I've been wondering

Why someone doesn't try a diesel/electric setup like a diesel locomotive has. I wouldn't think it would use much fuel to operate a DC generator to push around a car. All-wheel drive would be an added benefit. No batteries to charge either.

David_5

Diesel/electric

Should be able to make burn real clean because the engine only needs to run at one speed to make electricity.

David

Tony_8

actually

locomotives modulate engine speed with increases/decreases in load. Still, it shouldn't take much to move a car.

Matt Undy

Don't diesel engines get their efficiency form being to idle at very low speeds compared to gasoline engines? It seems to me that you'll only be losing efficiency by genreating electricity from kinetic energy, then changing the electricity back to kinteic energy. Is the reason that diesel locamotives use electric gernators efficiency, or is it to avoid the complicated mechanics that would be needed to drive and modulate power to each wheel mechanically? Hybird cars I believe have generators that are used for part of their braking so that the kinetic energy is stored in the batteries when they stop instead of being wasted as heat.

Higher overdrive gears may make the diesel run in a more efficent state at highway speeds once acceleration is accomplished. If the majority of diesel's efficiency coemse from lower idle then turning off a gas engine at cruising speeds may have a similare efficiency effect without the acceleration and environmental disadvantages. Many of the environmental disadvantages have to do with lower quality fuel.

Perhaps a propane hybrid would be a good idea. It burns much cleaner than gasoline so the engine lasts longer and requires less maitnance and at higher effieciencies the duifiulty in finding someplace ot buy propane would be less of a problem.

These are just some thoughts I had. I never quite understood the push for electirc cars by environmentalists, the electricity you get out of the wall isn't a very clean fuel. Something like 50% of the energy of the fuel used to make it actualy reaches your home between losses in the plant and huge losses in the distribution system and a lot of it is still made by burning coal, many times in plants without much polution control.

Matt

Dave Yates (PAH)

Same thoughts about total electric cars too

Same here. I thought they seemed silly given the need to suck up utility energy derived from an already inefficient use of fossil fuels. An electric fool for fuel?

That's what struck me about this rental car. While accelerating & using the gas engine, it's generating electricity to recharge the batteries, which doesn't differ much from the alternator/battery systems we already have. Then it simply switches over to the electric motor, which runs on the battery's storage power.

Imaginations of service trucks that can achieve 99 MPG in city driving are dancing in my head. I'd pay more up front costs if they become a reality.

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Kevin_in_Denver

never mind

Jed_2

100 MPH?

is that on the PA Audubon?

Wayco Wayne_2

The American

car companys have been trying to catch up in the market. I read that Dodge wanted to make a hybrid for their Durango vehicle. Isn't that an SUV? Other articles I've read say the hybrids are just an intermediate form while we move towards all electric. I did the math a few months back and even if we reach 3 dollars a gallon for gas, the price difference in the Civic Hybrid compared to the gasoline run Civic would take close to 5 years to make up the difference in purchase price. (Based on 20,000 pmiles per year, My wifes annual rate). I would love to have one just to play with for a while. Maybe I'll rent one if I go to Providence/Wetstock. WW

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singh

Chevy's silverado 1500 hybrid will be out this fall,But the gas mileage only increases by 2 gallons per mile?!(18 total hwy) I doubt suv hybrids will make a difference, or worth the extra costs.

The real gas guzzlers are commercial vehicles. Only about 6% of all vehicles on the road are commercial, but they consume 28% of the fuel demands.
Thats where the effort is heading for more efficient trucks and buses.

The shift will be gradual,from hybrid, to hydrogen, to fuel cells,but the technology is there,but no infrastructure.

Uni R

Locomotive

Modern locomotives have their AC alternator output rectified to DC and then inverted to 3-phase AC for the traction motors. I'm not sure what the overall transmission efficency but it is certainly far less than what automotive gears give us. It does however allow a train to get hundreds of tons of freight rolling with only 5000hp. To get all wheel drive more efficiently some agricultural vehicles use hydraulic drive.


I'm not crazy about hybrids for two reasons. I'm not excited about having to replace batteries (cordless drill batteries NEVER last long enough). These deep cycle batteries are very expensive and then there are issues surrounding their disposal. One thing they have found is that hybrid performance levels are nowhere near their claims when it comes to winter operations. Personally I like the ideas of improving small diesels.

Constantin

Hold on a minute...

... commercial vehicles consume much more fuel on a given day because they also get driven a heck of a lot more. Some tractor-trailer rigs spend 16+ hours per day en-route. However, if they are driven consistently, I doubt that their energy efficiency per mile driven (accounting for the cargo they move) is lower than that for most passenger vehicles. It's also the reason that trucks run on Diesel (~30% better fuel milage) and that a lot of money is spent to improve the aerodynamics/weight of rigs.

Anyway, on highway routes, etc. hybrids are not going help, rather they will hinder fuel efficiency. Regenerative braking, etc. only really benefits in stop&go traffic. Otherwise, you end up carrying a lot of extra weight for naught. Local delivery trucks on the other hand may benefit a great deal. However, fuel prices are still not sufficiently high that any major manufacturer wants to play guinea pig.

As I have stated in previous posts, I doubt we will ever see a Hydrogen transportation economy unless we find a way to create a lot of surplus energy (i.e. fusion). Even then, IMHO there simply are too many issues with respect to Hydrogen to make it a viable energy medium for transportation purposes. No amount of technology can get around the fact that Hydrogen is a much more dangerous fuel to use than just about anything in use today: You can't see it burning, it'll ignite/explode in a much wider range of air/fuel mixes than any other gas, it has a nasty tendency to leak, etc. In other words, Hydrogen is inherently unsafe and should thus not be used in circumstances that cannot be controlled carefully (i.e. stationary applications).

Let's face it: US vehicles have lousy fuel economy because the US drives bigger cars than the rest of the world, yet expects the same acceleration as the little rice boxes with 2.4L engines. Nowhere else do we see engines typically used in EU lorries giving SUVs the same pickup as a passenger vehicle. Extra-cheap gas prices subsidize the gluttenous use of fuel and as harsh as it sounds, I would appreciate higher fuel prices as a means to increase efficiency, to reign in urban sprawl, reduce the tendency towards a Wal-mart economy, and reign in other excesses only made possible by the lowest fuel prices in the western hemisphere.

Constantin

Diesel uses a different combustion model

Gas engines are dependant on the spark from a spark plug to ignite the fuel mixture. Diesel engines rely on heat and compression instead (hence the glow plugs). Where a typical gas engine experiences a compression ratio of 10-11, Diesel engines weigh in at 18. Due to the higher compression, more energy is turned into useful motion, allowing Diesel engines a 30% fuel efficiency advantage (on average) over Gas equivalents.

Diesel engines also typically have much greater torque though I doubt that will have a meaningful impact on fuel efficiency. Rather, it is very useful when trying to get a large tractor trailor off the line after a stop.

It is my understanding that the reason Diesel-electric locomotives exist is because Electric motors have even better torque at zero RPM than engines. In other words, they can apply a heck of a lot more power than a Diesel engine could unless it had a huge transmission. The electric motor eliminates the transmission, modern electronics allow any speed to be attained efficiently, and it would make sense to only use the diesel generator on tracks where there is no overhead power available.

Regenerative braking is quite attractive as a means of recouping some energy when you slow down. However, the process is not 100% efficient (transfer losses) and relies on braking that is gradual enough where the disk brakes are not used to supplement the electric motors/generators.

For that matter, US Diesel is only as dirty a fuel as it is because the US allows it to be. Elsewhere in the world, Diesel and its cousins (like #2 heating oil) are required to have a much lower sulfur content than over here. Were it not for the generous allowable sulfur levels, condensing oil boilers and furnaces would be much easier to implement... or catalytic converters for diesel trucks that capture and fully combust the soot we all associate with big rigs launching from a stop.

Propane is a non-starter, IMHO, as its more dangerous to handle than gasoline, does not have even the energy capacity of CNG, and is more expensive to boot. However, with the right tax incentives, the adoption of CNG seems to be quite high (at least by observing taxi fleets in western Canada, for example)

I agree with you that a purely electric car is not efficient, unless we find a cheap and relatively pollutionless means of generating power. On the other hand, in some locations, electrical transportation may be perfect, such as remote locations in the outback where sun is plentiful but fossil fuel has to be trucked in over vast distances. Once you set up a PV array in the outback, you can benefit every day from the beautiful weather and whatnot to keep your transportation option viable. On the other hand, refueling is big problem, as is the relative fragility of most electric vehicles.

Anyway, have a look at the current issue of Scientific American, they have a great article on Fuel Cells in transportation uses, including a chart that shows the relative efficiency of many different ways to power vehicles. Since they account for the relative effiency of harvesting various fuels (by including the supply chain for each fuel), the comparison is about as apples-to-apples as it gets in the popular press (May 2004 issue) Cheers!

singh

Funny,I was watching the program Scientic America with Alan Alda just the other day on PBS,and fuel efficient cars was the main topic.

Americans like SUV's this is true,but it turns out the Chinese like SUV's also. As of right now we are the bigger consumers of resources and contributors pollution,but if China keeps getting rich and each household obtains wealth and a car as they are beggining to do now,well...
P.S. where do you think all our scrap metal is going? You got it, building chinese cars and other products. Of course this increase in chinese manufacturing takes oil, driving up our costs at the pump.
its a Global economy. Oh , did I mentioned a little war that makes things a bit unstable.

True Hydrogen is a little dangerous, not according to some of the guys from GM and other car manufactures,they were pumping away ! : ) Why ,well hydrogen is very light,test on two similar cars one with hydrogen and one with gasoline,were intentionally ignited,the hydrogen burned, up and away and quicly burned out..The gasoline just sat in the other car and burned and burned and burned....
Then they showed one inventor who said Hydrogen run cars don't neccessarily have to have a unstable hi pressure tank in the car. he invented a sort of sponge ( sorry I'm not a scientist) that will absorb the hydrogen ,it is a strong medium ( looked like charcoal to me,but a metal alloy) that can even be molded into the bumpers of cars. Thats right, your gas tank will protect you in a crash!! I think GM was very interested.and Daimler -Chyrsler.

As far as hydrogen production,stations can be built very easily. All you need is electricity and some plumbing.
Reverse the process. fuel cells use hydrogen and electricity,by product water. Reverse that, take electricity and water , by-product hydrogen!!
These stations are already being built in Iceland. Iceland produces very cheap electricity from geo thermal springs that it sits on. They want to be totally oil independent.
Electricity production in US a little bit difficult,expensive and politically misaligned.

US has stricter emmision standards when it comes to diesel,not the EU. Mercedes and volkswagon disel are very common in EU, they have now just begun to meet our standars, and are now selling more diesel cars in US. Not the other way around.

The pradigm shift has begun, If you build it they will come.

Mark Hunt

Alan Alda?


How does pretending to be a "doctor in the military" qualify you as knowledgeable?

I'll bet "average America" said, "Hey! Alan Alda is on a program about energy! It must be good, otherwise he wouldn't lend his name to it! Gimme' the clikker!"

Nah. Didn't happen.

Ever play "King of the hill"?

Knock the guy on top off?

Nuff sed!


Mark H

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Mark Hunt

Kal?


Are you saying that by buying gas we are "feeding the terrorists"?

Last I checked America gets the least amount of imported oil from the places that "seem to have bred terrorists".

Google search "origins of oil" and see what you come up with.

It's not what you think and the evidence grows stronger every day.

BTW, would things have turned out differently if a vocal minority had turned out and raged "NO WAR FOR TEA" in Boston?



Mark H

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Constantin

Some counterpoints

Devan,
I am not going to argue that we cannot make Hydrogen work if we had to. After all, mankind put folks on the moon with late 50's technology. However, I remain convinced that other fuel sources and fuel mediums will remain more efficient than Hydrogen.

For example, the metal-hydride fuel tanks you refer to in your posts for the storage of Hydrogen are relatively safe. On the other hand, they are also heavy, expensive, etc. Putting the fuel into the bumper is nothing short of a publicity gimmick. Furthermore, a catastrophic tear through the matrix could allow enough H2 to escape at once to cause a nice little explosion, not the controlled deflagration you got to witness. I've seen enough rockets and one space shuttle go boom to know that Hydrogen demands a lot of respect.

Iceland has a lot of excess thermal energy they can harness. Note my post above mentioning that in the prescence of a lot of free energy, Hydrogen may make sense. In the US, this is simply not the case. Here, we generate electricity with an fuel efficiency of about 35%, IIRC, once all losses are accounted for. Now that we've wasted 65% of the energy, we are going to engage in a lossy process to make Hydrogen? How about using the fuel we would have used to power the power plant to power the car instead?

Frankly, I have a hard time believing that ethanol would not be a cheaper fuel source (the Brazilians have used it for years as a rather expensive foreign-reserves conservation device). At least Ethanol does not require the retrofit of an entirely new infrastructure. Or you could use a number of other biologically derived fuels like bio-diesel, rape-seed oil, etc. At least these fuels are renewable in nature, relatively benign, and do not require a very expensive infrastructure upgrade.

As for allowable Diesel contamination, I'm afraid you are dead wrong. The US allowable sulfur contamination for highway-use Diesel is currently set at 500PPM, slated to be reduced to 15PPM by 2010. Off-road vehicles are currently allowed to use Diesel with a contamination up 3,500 PPM of sulfur with a reduction to 500PPM fuel by 2010. The EU standards are already around the 15PPM level, allowing the usage of catalytic converters that would otherwise get poisoned by sulfur.

As for actual emissions requirements, I simply cannot see how the US engines could somehow scrub the almost 40x more Sulfur in the fuel from the exhaust stream... So how is it that the EU is playing catchup to our standards? They start with a cleaner fuel. By default, they have to produce a cleaner exhaust, at least as far as Sulfur is concerned (NOx could be another story).

Note also that it is EU diesel engines getting sold in the US, not the other way around. To the best of my knowledge, the US has no small diesel engines available... the US never developed them. Chrysler is using a MB block, VW has developed its own engines for years, as has Fiat, Peugeot, Renault, etc. Heck, even Ford and Opel/Vauxall (i.e. GM) have developed Diesel engines in Europe for the European market.

The sale (or lack thereof) of Diesel passenger vehicles in the US has nothing to do with emissions standards and everything to do with demand. There simply was no demand for small Diesel powerplants due to the low price of gas - why bother with efficiency, slower pickup when gas is $1/gallon? Note the many post-oil-embargo MB "D" models still cruising around... Demand for diesel vehicles in this country has traditionally correlated with high fuel prices.

Then VW shook up the industry with the TDI models that allowed excellent fuel milage in a economical package. The Turbo boosts output to the point where the Diesel is almost as quick as a gas engine, while the Diesel reduces fuel demand 30% below Gasoline engines. For example, the Chrysler Minivan has been offered for years in the EU with a MB diesel engine that has a advertised a single-tank fuel range of about 1,450km (~900 miles!!!).

Coming back to heating technology, this is the reason that the condensing oil boilers on offer in the EU are not offered in the USA. Our heating oil is simply too contaminated with Sulfur to prevent the secondary HX's from being eaten from the inside out. There is one condensing furnace (Adams/Dornback) and one condensing boiler (Monitor) available in the US, and the consensus from Oiltechtalk is that the incremental efficiency increase of these units will not pay for itself unless you use low-sulfur kerosene fuel.

singh

I'm not argueing?
I belive we can do better than the internal combustion engine ,that technology has been around for 100 years and has not change much.
I could not care if it was hydrogen ,ethonol ,diesel..
give me a car with hi mpg relativly inexpensive and clean ,quiet and comfortable and good for the earth and i'll buy it. Sound familar radiant guys?
Sorry,my info must have been wrong, i recently looked at some sprinters, they been in use in europe for over a decade,the dealer noted that they had to make modifications to the emmissions in order to sell in US. Same for Mercedes and VW.
Ford is coming out with a Focus model diesel next year.Interesting.

Alan Alda is just a host, not a scientist most out of work actors narrate TV shows???

I'm an optimist, I belive we can do better, in our growing world, only 30% of the pop. owns a vehicle,what would happen if the rest of the world decide to buy a car. We have to do better.
Enough said.

Constantin

No worries, mate!

I'm all for increasing efficiency. In fact, I hope that the US at some point makes fuel and energy sufficiently expensive to reward those who conserve rather than subsidize those who do not. One of the things that is striking about the US is the sprawl, which is only made possible by cheap land and even cheaper automobile transportation. For the most part, public transportation is nonexistant and even the supermarkets have valet parking in California (!!!).

The old world typically featured clustered housing for a reason. Put enough houses together and you create a viable local economy. First comes the baker, then the post office, etc. Over here, such micro-economies have been stamped out in many places via Wal-mart and other mega-malls. It's a pity because it anonymizes society. The degree to which the US is a transaction-oriented economy as opposed to a relationship-oriented one is striking and I believe that the sprawl is one of the reasons it came to be that way. It's also one of the reasons that visiting US citizens usually have a hard time dealing with the locals in the EU. They don't treat a visit to a store like they would a visit to someones house, they treat it like an excursion to the mall.

I agree with you wholly that we can and must do better. The rest of the world is playing catch-up to our living standards and unless we find a way to conserve resources, it's going to turn into a battle royale for the few resources that are left at the end of the day. The sad thing is that we have the resources, wealth, etc. to show the world a better way. However, the resources being thrown at hydrogen research projects (in the form of a thinly-veiled car industry subsidy) do not seem to coincide with sound science, IMO.

On the other hand, with **** Cheney's retirement fund in mind, would you allow the exploration of alternative fuels that do not require the expertise of Halliburton? I didn't think so. Lest I sound partisan, I doubt that Mr. Kerry will have the will either.

jackchips_2

You,

> I'm all for increasing efficiency. In fact, I

> hope that the US at some point makes fuel and

> energy sufficiently expensive to reward those who

> conserve rather than subsidize those who do not.

> One of the things that is striking about the US

> is the sprawl, which is only made possible by

> cheap land and even cheaper automobile

> transportation. For the most part, public

> transportation is nonexistant and even the

> supermarkets have valet parking in California

> (!!!).

>

> The old world typically featured

> clustered housing for a reason. Put enough houses

> together and you create a viable local economy.

> First comes the baker, then the post office, etc.

> Over here, such micro-economies have been stamped

> out in many places via Wal-mart and other

> mega-malls. It's a pity because it anonymizes

> society. The degree to which the US is a

> transaction-oriented economy as opposed to a

> relationship-oriented one is striking and I

> believe that the sprawl is one of the reasons it

> came to be that way. It's also one of the reasons

> that visiting US citizens usually have a hard

> time dealing with the locals in the EU. They

> don't treat a visit to a store like they would a

> visit to someones house, they treat it like an

> excursion to the mall.

>

> I agree with you wholly

> that we can and must do better. The rest of the

> world is playing catch-up to our living standards

> and unless we find a way to conserve resources,

> it's going to turn into a battle royale for the

> few resources that are left at the end of the

> day. The sad thing is that we have the resources,

> wealth, etc. to show the world a better way.

> However, the resources being thrown at hydrogen

> research projects (in the form of a thinly-veiled

> car industry subsidy) do not seem to coincide

> with sound science, IMO.

>

> On the other hand,

> with **** Cheney's retirement fund in mind, would

> you allow the exploration of alternative fuels

> that do not require the expertise of Halliburton?

> I didn't think so. Lest I sound partisan, I doubt

> that Mr. Kerry will have the will either.

eleft_4

Mark,
Your thinking past the front page falls on "deaf ears", as the saying goes.

I'll bet you don't miss any nails.

al

jackchips_2

You,

partisan, Constantin? :-)

How is your Mom?

Constantin

The oil has to come from somewhere

Our oil comes primarily from the Americas in the form of Alaska, Mexico, and Venezuela, IIRC. Natural gas (LNG) is shipped in from Algeria and Tobago. However, if and when Mexico goes dry, we will require fuel from farther afield. In fact, our refinery capacity is apparently so low that we now have to import fully refined fuel (i.e. gasoline, etc.) rather than crude. I'm split whether this is a good or a bad thing.

Coming back to the terrorist comments, it is well-established that the Saudis and US seriously subsidized the Mujahedeen in Afghanistan during the Russian occupation. The Pakistanis held out their hand along the way and the ISI (their version of the CIA) grew fat and increasingly militant as a function of time. Remember that it was the ISI that allowed the Saudis and US to establish Madrasses, military training camps etc. in the border regions and that it was the ISI that armed and trained the Taliban.

Do you know how many Stinger missles are still not accounted for in Afghanistan or who holds them? Well, the CIA doesn't either... We armed and trained the very people that now want to slit our throats. The irony would be priceless if it wasn't so scary.

The sad truth is that the constant meddling in Afghanistan and elsewhere has created an entire generation of folks who hate the US. They don't hate our freedom, they hate us for the collateral damage our govenment has inflicted on them, both real and preceived. A goat herder in the Hindu Kush couldn't care less about freedoms in a faraway land, he cares about the bomb that killed his village elders, or the pictures of alleged US atrocities inflicted on his people.

To give you an analogy, the US has been waging a domestic "War on Drugs" for decades now, but it still has not compelled the US government to invade Europe to shut down Amsterdam (a hotbed of legal drugs) or Zurich (where pure Heroin is handed out to addicts to cut down on street crime).

While the US has not consumed huge amounts of Saudi oil, they have been the de facto protector of that country for the last 50 years. Were it not for Saudi oil, world oil prices would be much higher and they would fluctuate a great deal more (the huge reserves and pumping capacity of Saudi Arabia sees to that). How else qunch the thirst of Japan, Europe, etc. in addition to the vast demands that US oil consumption places on the world?

The Saudis continue to struggle with the shism brought on by modernity and the strict interpretation of Islam (Wahabinism) that allowed the Al-Saud family to ascend to power 100 years ago. It will be interesting to see how the family will reform the religious schools, etc. to temper the hotbeds breeding fanaticism and radicals. One day, we may even see houses of worship for other faiths in Saudi Arabia.

May I suggest you read Ghost Wars by Steve Coll for a comprehensive look at our involvement in Afghanistan. Perhaps then you will better understand why many people there hate our governments guts.

Back to fuel, it is interesting to note that the first generation of Diesel plants produced by Rudolf Diesel used peanut oil. Even in the early 1900's it could be done.

Constantin

She's much better, thank you!

After a week with us she decamped to Maine where she continues to recuperate. It's going to be a month-long process. However, I think she'll be fine and that's the most important thing.

JimGPE_8

Wow!

I guess Wallies read a lot!

May I just say that the higher efficiency of the diesel cycle over the auto cycle (gas 4-stroke engine) is due to the fact that the fuel is injected in the expansion stroke rather than in the intake stroke.

It has nothing to do with compression ratios.

Constantin

Humm, not an expert myself but...

...the folks over at Howstuffworks disagree. They state that the compression is what makes the difference, not when the fuel is injected. As a correction to my previous post, compression ratios in Diesel engines can reach 25:1, almost 2.5x more than what gas engines will tolerate. The higher compression must be one of the reasons that Diesel blocks tend to be heavier than comparable gas engines... somehow that pressure has to be contained!

In another tidbit I didn't know, they also give you the chemical makeup of Diesel vs. Gas and the two heating values. As Diesel has 147kBTU per gallon and gas only 125kBTU, this is yet another explanation why one gets better gas mileage with a Diesel than a Gasoline engine - the energy density of Diesel is higher. Plus, it's easier to refine and hence cheaper to make than gas.

Here are some additional links which also claim higher efficiency due to the compression ratio See Integrated Publishings more complete explanation: part I, part II, part III, part IV, and part V.

JimGPE_8

I'm pretty sure they're wrong. I'll look it up tonight, but in first year Thermo we studied the thermodynamic efficiencies of the engine cycles, and I'm pretty sure I'm right. You see it on the pressure/enthalpy chart representation of the cycle. It is a waste of energy to compress the fuel.

Also, one of the worst drains on efficiency is clearance volumes - the volume that is left at the top of the compression stroke that means with each cycle you are compressing and expanding a mass of air with no benefit. Clearance volume inefficiency would get worse with higher compression ratios. You are compressing and expanding more mass.

Any input from Mad Dog, our resident Phi Beta Kappa member?

hr

locomotive breath

With tier 2 EPA emissions kicking in next year requiring cuts in NOx and particulate matter, GE has built the most efficient locomotive engine ever. Supposed to run 40% cleaner and 3% more fuel efficient, saving about 9000 gallons per year per engine. Twin V12s power most engines with pistons as large as buckets.

The diesels spin alternators about 5 foot in diameter, which power six electric traction motors. The motors turn into generators to brake the train and energy created powers a grid (a large heat gun) to disapate the excessive current.

Zero to 60 mph in just under 45 seconds for this 207 ton chunk. According to Popular Science mag.

hot rod

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eleft_4

comprehensive ?

Do you think taking one mans opinion is gospel?
I see more & more spinning for profit today then ever in my life time.

al

Constantin

Not Gospel, Not Opinion either IMHO

Nothing unusual there.

However, I'd recommend a look at his book anyway.

Every chapter must have 35+ footnotes with full references to boot. Mr. Coll is the managing editor of the Washington Post (not exactly a bastion of liberal thought) and was stationed in SE Asia for three years.

Granted, you can shape an argument one way or another using selective quotes, out of context stuff, etc. However, I found the book an engaging read, particularly with respect to the many references he made to publicly available material.

For example, we all know that the CIA trained Mujahedeen to use Stinger missles. The current and previous administrations have also acknowledged that not all Stinger missles have been accounted for since wars end. So with both republican and democratic executive branches offering $$$ for the recovery of Stinger missles, who is spinning whom?

singh

Check out www. dieselnet.com/standards.
may be helpful.
also www.ovonics.com
Tell me what you think.

devan

Constantin

Quick Review

The Dieselnet pages seem to show allowable emissions. Note the absence of sulfur and the different units of measure (g/km vs. g/mile). This makes objective comparisons somewhat more interesting. If my math is wrong, please excuse me!

Starting with CO, note the allowable CO levels as of 1997 for passenger cars (Tier 1 vs. Euro II). The allowable CO levels in the US are higher by 2x. As best as I can tell, the Euro II+ standards are all lower in terms of allowable CO than the US, even at Tier 2. The only exception are the LEV II standards promulgated by CA.

With NOx there is no Euro 1+2 standard. However, as of Euro III (2000), the allowable NOx is below US tier I and above tier II, bin 9 and less. What bin number applies to what passenger vehicles remains a mystery to me.

Particulate Matter (PM) appears to entail a flip-flop. As of EU II and Tier 1, the EU has less stringent standards from the getgo (until 50,000 mi), then the US relaxes its standards to allow more PM as of 100,000mi. Euro III has the same PM standards as the starting point for Tier 1, and the Tier II regs make life difficult to compare once more.

As with all comparisons, also note the absence of some measures such as sulfur, etc. that are much higher in the US than in the EU due to cleaner fuel regulations over there. The Upshot: I fail to see consistently tighter US-wide emissions standards than what is used in the EU. Please advise me if I misinterpreted the charts or committed a conversion error. Cheers!

eleft_4

who is spinning

OK, point well made. Just keep an open mind.

Who is whom or whom is who.

Maybe 520 people in high places representing all kinds of comb-over and hair pieces with a common answer to any question....."let me say this".

OH NO not deception.

al

Kal Row

They are right – “volumetric efficiency”

an air breathing engine - internal or external (turbine), before it's anything else, it must be an air pump, and the better it pumps air, the better an engine it is, the better ratio of air to final compressed volume in the combustion chamber, the more chance of getting each molecule of HydroCarbon to connect with heat and O2 - unfortunately gasoline's low temp explosive quality, makes it unsuitable for such high compression, so we must do other tricks to extract the more impulse energy per pound, it possesses over diesel fuel, but the difficulty in controlling that gasoline’s force – make’s it loose against diesel at the end of the day – though a 1 liter gasoline engine with a 32 tiny cylinders in a radial or X configuration, driving a motor generator or an infinitely variable transmission would be another matter

but, this whole conversation is moot – since at 75million barrels of oil per day, this planet is running out soon – so we have to start putting linear induction coils into roadways now – and start producing electricity efficiently – with renewable energy sources – sooner than later

we should never have given up panama – because as long as this planet is rotating, at that latitude, the planet is turning a 950 miles an hour, and the pacific ocean can pour into the Atlantic ocean at quite a clip, the central American power authority has already dug 11 electric turbine tunnels, and the are digging many more – in fact with cable laid across the bearing strait, you can power the whole planet from there, the only thing that should be using fossil fuel, is aircraft, boats should have wind turbines and tow 20 miles of floating solar cells, all trains and autos should be driven by induction coils in roadways (yes – I know, they would need batteries to get them up to speed, and but the induction coils could maintain it – and charge the batteries)