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Diesel Cars - High-Tech Low Tech
jonbrewer writes: "The NYTimes is running a great article talking about the growing trend of Diesel cars in Europe, their fantastic mileage, and the fact that America ignores them. While the article wows us with 78mpg for the Audi A2, I'm happy with the 45mpg my TDI Golf makes." Until diesel pumps are everywhere, I think I'll hold out for my solar/hydrogen-fuel-cell/flywheel hybrid.
I've been working on a project at Georgia Tech called FutureTruck, which is sponsored by the Department of Energy and some major automobile manufacturers. If you're interested, the website is here. GT is one of 15 schools from around the US and Canada that were tasked with taking a GM Suburban, a rather poor MPG performer but popular in today's market, and making it cleaner, more efficient, and (if possible) even more consumer-attractive.
;)
Just a couple things I've noticed over the past 2 years of this project:
1. Fuel cell vehicles are still a ways off. The hydrogen containers are bulky and heavy, and a system still costs around $1 million.
2. Diesel/biodiesel looks promising but a few problems remain - more polluting than normal gasoline, different performance issues, and such. However, they are more efficient overall. Paired with an electric motor, diesel engines could turn out to be cleaner and more effective than gasoline-only vehicles.
3. Electric-only vehicles are very limited in range and scope. Batteries are still heavy, even the 'new' kinds of batteries like Lithium-Ion. Combined with the need for a charging/recharging infrastructure, and the (at least) American desire for power, the electric-only vehicle will likely be relegated to shuttle cars on a set path.
4. Hybrids, like diesel-electric or gasoline-electric, seem to be the wave of the near future. I believe all the schools participating in FutureTruck are using a hybrid system of some sort. The Honda Insight is a good example of a production car that is a hybrid vehicle. It can reach about 70 MPG after a bit of driver training/getting-used-to. There are an array of configurations and methodologies for hybrid systems that I won't get into here, due to space considerations. But I believe, and so do a lot of other schools and even car manufacturers, that hybrids will pave the way in the near future. Beyond that... maybe they'll have fusion power worked out by then.
I hope this helps some of you out with what's going on in the alternative fuels/powertrain area. I am by no means an authority on this subject, so visit the Department of Energy, the Argonne National Laboratories, and the Society for Automotive Engineers websites for much more detailed information. Those websites are here, here, and here respectively.
Your comment is outdated by about 20 years. The new diesel engines coming out of europe are at least as clean as their gasoline counterparts.
Until diesel pumps are everywhere, I think I'll hold out for my solar/hydrogen-fuel-cell/flywheel hybrid.
And that's exactly why they aren't eveywhere. Because people are 'holding out'. New technology (even sometimes old technology like deisel) takes adoption.
-- Truth goes out the door when rumor comes innuendo. -- Groucho Marx
Yeah, but they do it for a different reason, IIRC. Diesel locomotives use a hybrid arrangement because a pure diesel locomotive would have trouble moving away from rest smoothly (imagine changing gears on a locomotive . . . ). I don't know whether they use regenerative braking or not, though . . . as diesel locomotives tend to not brake very often it might not be worth it.
Go you big red fire engine!
Any sufficiently advanced technology is indistinguishable from a rigged demo
--Andy Finkel (J. Klass?)
Of course, while petrol is as cheap as water in the US and Australia we'll all keep pouring fuel down our oversized, overpriced and unsafe (both for drivers, passengers and especially for other road users) SUVs. Sigh . . .
Go you big red fire engine!
Any sufficiently advanced technology is indistinguishable from a rigged demo
--Andy Finkel (J. Klass?)
(These new diesels are known as Clean Diesels, and are a favourite of my local bus company, which is how I know about them.)
Actually, your bus company's diesels lack the latest advancements -- a Peugeot 607 FAP (or Citroen C5 and Xsara, or -- again -- the newest Peugeot 307 FAP), are equipped with a self-regenerating particle re-burner. Basically, the thing makes the particles go through a catalyser, which eliminates them. Once every roughly 20000km, the engine's cycle is automatically tweaked, so the exhaust gases are a bit hotter for a while, which cleans the filter. You don't even notice anything.
While this new filter is currently fitted only on a single carmaker's higher level cars, you can bet that in 2 years, they'll be almost everywhere (just like the HDi/TDI/dCi/JTD engines rule the market today. Only the cheapest cars still have atmospheric [diesel] engines, and some carmakers like Fiat (owner of a famous fast expensive red car producer) seem to just sell common rail stuff these days.
My car is technically quite old ; it burns 4L/100km (of diesel), which is quite good. The next generation Peugeot/Ford[europe] low-end diesels have a target of 2.5L/100, which is quite excellent...
There are other "advances" (hmmm. Let's call that, re-advances). First is Aquazole (an emulsion of water in the diesel oil); most city bus companies use them nowadays (when they're not already burning natural gas). Aquazole is quite cool, in that the combustion is only necessary to heat the gases ; most of the mechanical energy comes from the (more or less) adiabatic relaxation of gases. It makes a lot of sense to have the strict minimum of petroleum-derived gases, and have the majority of relaxation gases being simply water vapour. When the proportion's right, the exhaust temperature is just a little above 100C, and the efficiency's at its best [*]. As Aquazole is a bit (energetically) expensive to produce, another way (which has been quite used in the aeronautic industry of the piston era) is to inject a suspension of water droplets in the cylinders just after the combustion began. Now these subsystems get a lot of attention too...
Anyway, reducing the overall fossil stuff consumed is a Good Thing. Whether the byproducts are soot, CO2, SO2, Pu, Th and whatnot, it's always dirt.
[*] unfortunately, lower temperature exhausts is diametrically opposite to the way particle filters work ; those need higher temperature exhaust gases to work efficiently. That'll certainly get worked out pretty soon, though.
(finally, the gasoline engines aren't sitting either. Common rail ("EDI/GDI/HPi"), Altivar [alternator is also an auxiliary electric engine. When you're sitting in a jam, or at a red light, you just don't burn anything] (1 or two years from Renault to market now), and electro-magnetically driven valves (dump the camshaft, and gain features like dynamically adjusting the valve cycle to better burn the combustible, or dynamically disable a few cylinders when they're not necessary, etc. Costs some electric power at high RPM, unfortunately, but counts as extremely cool in my book).
[electric engines will be cool when the batteries are able to last 200000km (not on a single charge, of course), and be produced, recharched, and recycled (ecologically) efficiently. As long as these batteries represent more polluent (concentrated in a small volume but still potentially extremely harmful) than what my Saxo will exhaust in its whole life cycle, then no thanks] [and I'm an all-out nuke fan]
The reason diesel supporters claim they produce less soot is because the soot particles are smaller now--too small to be detected by current tests, so it seems like there's less soot, even though total soot output hasn't really changed. Unfortunately, these smaller soot particles are harder for your lungs to clear out, because they can more easily embed in the lung walls, instead of getting swept out by the natural mucous flow. Because of this, they're likely worse for you. (These new diesels are known as Clean Diesels, and are a favourite of my local bus company, which is how I know about them.)
If you Americans really want to save the environment, switch to nuclear power. Build the freaking Yucca Mountain repository, and stop worrying. You're all getting more than 50 times as much radiation from naturally-occuring radon as you are from the nuclear industry. Even if you happened to be living at the outer fence of Three Mile Island during the accident, you still only would have taken a dose equivalent to the normal naturally-occuring yearly dose (~1 milisievert). It's just not a big deal. If you still feel concerned about radiation, get your house tested for radon, and don't fly to France (flying exposes you to higher levels of cosmic radiation, and France has high levels of naturally-occuring radon).
Once you have clean electricity, electric cars actually make sense. As it is, you're mostly just moving the pollution around. (Yes, yes, I know you can produce electricity more cleanly on a large scale than you can produce power in a car, but, when you factor in transmission losses and other inefficiencies involved in electric cars, it's all about the same, so screw off).
There's a reason we have been weaned away from biodiesel - it means empowerment for the individual and power away from government & corps. - because biodiesel can be made by you and me.
Also the US government especially dislikes the plant Cannabis Sativa which is especially good for producting this product as well as many others.
From an agricultural POV a plant where the whole thing can be used for commercial product makes a whole lot of sense.
Trains can also haul a lot more stuff than a truck can -- there can be trains with dozens of cars, but a truck with dozens of trailers would be a real menace.
In Australia they have these things called "road trains". Effectivly they are a truck with lots of trailers (and a sign on the back to tell people not to try overtaking one.)
...major improvements in electric engines.
One of the big bitches of electric cars is (besides battery life) the poor power/weight ratio of the electric engine against the gas (petrol) engine. Also, even more damning, is the relative reliability of the gas engine. What we really need are people putting alot more effort into making a better, lightweight electric engine.
We already have the parts to build a really good hybrid gas/electric car (which, face it folks, is the only kind of low-emissions vehicle you will see for years). We have the following parts:
The Honda Inspire and the coming competition from Nissan and Toyota are OK, but face it, we need something about the size of a Honda Accord, not a Honda Civic CRX. I can't see any reason (technically) right now why someone doesn't mass-produce a converted Accord. I mean, you can use the exact same design (maybe cheat and use alluminium body panels), just with a new powertrain (with an electric engine, you should probably have a continuously variable transmission, rather than an "automatic", and definately not a "standard") and still get at least 70+ miles/gallon (that is, 30km/l).
Hell, with the $4k US tax credit for buying a low-emission vehicle, and gas here at $1.75 in the DFW Area, I'd spend $5k more for a converted Accord over a normal one, and still make out like a bandit. So who're the morons in the Marketing Depts at the car manufacturers?
....in many European countries. It was a hot subject in the mid nineties, and heralded as a low pollution fuel** but the taxation in many places has increased to the point where diesel is now more expensive than petrol and thus mitigating some of the savings; fuel consumption differentials still ensure there's a chunk left though.
When diesel was hot, there was a move to increasingly high performance and larger diesels in small cars, thus eliding much of the economy value excpept on long trips - the Citroen ZX TD Volcane is a classic example - 1.9 turbo diesel, around 135 bhp in a small hatchback, makes 50 mpg* or so on the morotway but below 25 mpg* in traffic.
* Imperial gallons - US deduct 20% from those figures
** Ah yes, pollution - diesel produces a lot of unsightly smoke, but there is very little in the way of chemical pollutants, NOx etc in modern diesel exhaust. Diesel smoke is just that, smoke - it is much more environmentally friendly than the stuff you can't see that comes out of a petrol engine, cat or not - catalytic converters just don't work on short journeys. Ever smelled the (catalysed) car in front fart? That's hydrogen sulphide, and it isn't good for you.
Someone designed a wonderful system for dealing with the particulates from a diesel, which would involve placing a cotton wadding filter canister on the tailpipe - these would be washable and exchangeable at fuel stations, once per tank of fuel for a couple of dollars.
Another great thing is lean burn technology for petrol engines - great technology, no political will. There was so much political momentum behind the cat solution (not least because it came from America so must be cool) that superior alternatives got squashed.
I live in the aforesaid land of the free (Austin, TX to be exact) and yes, there is a long way to go in addressing pollution. OK, so they have cats here and people in Texas typically drive far enough for them to have an effect, but there's no emissions check whatsoever in what passes for an annual vehicle inspection in the lone star state. You can quite legally drive a 17 year old petrol Suburban (river barge disguised as a 4x4) that has the energy consumption of a small third world nation, blows more smoke than a badly tuned diesel under full load, and who knows what invisible noxious gases besides, and get away with it until the thing literally rusts apart.
The low fuel prices (petrol is literally half the price of bottled water, currently $1.35 to $1.70 per **gallon** depending on octane) and the local prediliction for having a huge-ass pickup truck as personal transportation don't exactly help - to set context for European readers, over here a Land Rover Discovery literally is a small, economical family car (and that's the 3.9 V8 petrol model, they don't even sell the diesel models).
Europeans just wouldn't understand - Texans really, truly do drive pickup trucks instead of cars, even if they rarely have a passenger and never haul a bigger load in them than a bag of grocery shopping; roughly half the *software dvelopers* in our company drive one (empty of course) to work every day. There is some concession to economy - almost none are 4 wheel drive, and a 3.8 V6 with a manual gearbox is more typical than the traditional 5.x V8 slush-o-matic, but moving a brick shape throuhg the air isn't cheap; 17 mpg US (21 mpg Imp) is considered *good*.
Until diesel pumps are everywhere, I think I'll hold out for my solar/hydrogen-fuel-cell/flywheel hybrid.
But diesel pumps are everywhere, at least near where I live (Toronto), where would many trucks get their fuel? Not many specialized diesel stations around. Almost always cheaper than regular gas, although a bit worse for the environment.
Here in the Bay Area a numbers of cities are running part of their fleets on diesel from recyled cooking oil - it's really wierd you go past one and it smells like fries :-) Apparently its low polluting and cheap, and the main drawback is that you need to replace all the rubber parts in your fuel system with synthetics and be carefull about changing your fuel filter more often
You can't compare a truck motor with the diesel motor that goes into a TDI Golf (or Passat, which I happen to have), especially when it comes to particle emissions.
One problem is very low temperatures. Below -20 Celcius, Diesel can "flock" which prevents the engine from running (even with gas mixed for cold protections you don't get much lower than -20 celcius). Countries like Canada would require some external heating for the motor during winter.
What is also relatively new is that the TDI Diesels get as much horsepower per engine-volume, of course coupled with a much higher torque. My 2.5 V6 TDI has 310Nm torque, which is more than the 2.9 gasoline Passat.
Micro carbon soot from diesel combustion in automobilies is a deadly carcinogeon and causes lung cancer. You know that lovely smell when a truck or bus drives by. Well, that's diesel. Diesel proponents say that magic "filters" can do the job, however, application of such filters reduces engine efficiency making such engines no more effiencent than gasoline. There are many new technologies on the horizon, including a high pressure combustion which works much like diesil but works with any hydrocarbon that are far better than diesel.
Someone you trust is one of us.
The US at least isn't on the right track to reducing emissions/pollution. A lot of pollution comes from smaller very very dirty gasoline engines used in things like lawnmowers and leafblowers. These should simply be powered by electric engines.
Buses in the US do often use diesel. This is also foolish at this point as Hydrogen works well as a fuel for buses and is infinitely less polluting. Munich, Germany already uses Hydrogen powered buses and they are being taken up in other European cities. I think a few American cities are exploring the concept as well.
I'm not entirely sure why this article states it's a 'Growing Trend'.
:-)
In the UK, diesel cars tend to be just as popular as petrol. The old Diesel Peugeot 205 I had used to get at least 55 to the gallon.
I think this just goes to show how insular the States is when it comes to seeing viable alternatives to problems.
Another fuel on the increase is LPG (gas). My Dad, over 20 years ago, had an LPG car. The conversion was fairly cheap and easy. Effectively, you had a duel fuel car (petrol/ LPG), but LPG was half the price of petrol for more or less the same economy. After successive Tory goverments, the LPG stations disappeared (the Tories didn't care about viable fuel alternatives or public transport), but recently, they've started to come back, because the price of a gallon of petrol is now so expensive in this country. The quantity of LPG stations is on the increase.
Petrol, like everything, is a finite resource. No doubt, US automobile manufacturers will only consider an alternative until the last oil well dries up.
Of course, if anyone should put a good electric vehicle my way, I certainly won't object...
M.
I just wish my Audi got 78 Mpg. It uses oil at about that rate though
First off, you are probably confusing the power ratings of IC (internal combustion) engines and electric motors. IC engines are rated at peak power (the most they can produce, which is at a very limited speed range). Electric motors are rated at continuous power usually, which is anywhere between 7 and 8 times lower than their peak power.
If you check out AC Propulsion, they have a motor that produces 165 lb-ft of torque, and 200 hp. It weighs 110lbs. Unless you get into motorcycle engines, or some of Honda's high-revving wonders, you won't find a comparable power-to-weight ratio in an IC engine.
Electric motors are also much MUCH better at producing torque. If you look at the specs for any given motor, they will usually give two ratings, one from zero to a given rpm, which is its torque rating. How many IC engines do you know that can give 100 lb-ft of torque at zero rpm? None. You get a lot more grunt out of an electric motor than you could an IC engine, unless it's absolutely huge (Corvette? Mustang?).
As for reliability.... IC engines have, what 500, 1000 moving parts? How often do you have to change the oil? Spark plugs? Timing belts, fan belts, water pumps, etc., etc.? An electric motor has ONE moving part. DC motors have commutators, which are sliding contactors that can wear. But AC motors have none, just the rotor moving inside the stator. How is one moving part less reliable than 1000? Unless you have some good solid (or even believable generalized anecdotal) evidence to the contrary, I can't believe that any combustion engine is more reliable than an electric
Who says we need something bigger than a Honda CRX, anyways? How many people do you take to work with you when you drive? I don't take anyone... a 2 seater would be 100% too big! If you're thinking of using it as your primary vehicle, yes, you need something bigger. But right now the best place for EV's are as second cars, for commuting purposes.
Mr. Ska
I slit a sheet
A sheet I slit
Mr. Ska
There's one big (by which I mean HUGE) problem with flywheels, particularly high-speed types. A flywheel is a large weight spinning around a central axis; it is a particularly efficient way of storing energy, if the bearings are good. Unfortunately, flywheels have another name: gyroscopes. Gyros are not used primarily for the purpose of storing energy, but they are functionally the same thing, a weight spinning around a central axis. Now, ask any pilot or physicist a few questions about gyros, and you'll hear the word "precession."
Precession is the tendency of a gyro react to an applied force as though the force was applied 90 degrees ahead in the direction of rotation; that is, if a gyro is spinning clockwise, and you apply a force at the top (12 o'clock) position, the gyro will react by moving in the direction of the force, but at the 3 o'clock (right side) position. The result of this precession in a car would be to induce a force 90 degrees away from an applied force. The applied force could be anything--a bump, a turn, or cresting a hill (changing directions in the vertical plane); cresting a hill is a particularly insidious problem, as it would reduce the weight on the wheels (if done at any significant speed, like on the highway), and thus reduce the traction between the tires and the ground. That processional force would tend to induce a roll, pitch, or yaw moment in the vehicle, depending on the applied force and the orientation of they gyro-flywheel. Such a force could be very strong indeed, as it is related to the mass and rotational speed of the gyro (related to stored energy); at 100,000 RPM, or even at lower RPM and significant mass, you are still faced with a potentially significant precessional force, which would tend to reduce the controllability of the vehicle. I, for one, would not want to be on the wrong end of that equation.
One possible solution to that problem is to use dual, contrarotating gyros, but that poses problems of its own. The gyros must be properly synchronized; loss of sync will result in one gyro having a stronger precessional moment than the other. Another is that a synchronization system adds weight, complexity (additional points of failure), and reduces efficiency of the system.
Lesser problems, also mentioned in other posts, include imbalance (a slight imbalance, rotated to high speed, will result in significant vibration, causing rough running and substantial bearing wear) and flywheel damage--the slightest imperfection in the flywheel, accelerated to 100,000 RPM, could easily result in flywheel failure, including the assiciated problems of shrapnel (ever see a rotating object come apart? pieces everywhere) and imbalance (lose a chunk, suddenly the balance is gone).
In short, while flywheels sound like a good solution, they are really quite impractical for automotive use. The drawbacks are far too significant, and have too much potential to be dangerous, to allow flywheels to be effectively used in cars.
(And yes, I know that cars do have small flywheels in the engine, but they are just that, small, and only spinning at a few thousand RPM's. They just provide steady energy for the engine between power strokes.)
"Make it ten--I am only a poor corrupt official."
--Captain Louis Renault (Claude Rains), Casablanca
Forget diesel, I want a grease powered car! Those fancypants Detroit automakers and Texas oil drillers may think they have a hold on the American market. They may think the American people are too stupid to convert to cheaper, cleaner, more efficient technologies already proven overseas, but we'll prove them wrong. Pull up to a McDonalds and siphon some fuel from the Fry-O-Lator, that'll show 'em.
My Karma is so good, I'm the Dalai Lama...or something.
Check out the hemp car, a Mercedes Benz touring the U.S.A using hemp-based biodiesel. Hemp is such a great plant, it's a shame the D.E.A won't let us grow it!
Biodiesel could be the next great thing, outside of the US of course. Plus it helps out the farmers of this country that have been struggling to make ends meet.
It's time for the USA to take the lead in adopting new transportation technologies, and time to ditch the gasoline engine. Unfortunately, with the ExxonMobil Bush/Cheney team in command, it's gonna get worse before it gets any better.
~~+++ATH0 . . . END OF LINE