Jake Staub writes "Just replaced the gasoline engine in a Honda Insight with a Diesel engine. On a 3,000 mile cross-country shakedown journey the car averaged 92mpg over 1,800 miles. Around a very hilly town in Northwest Washington, the car is averaging 78mpg. These mileage averages are without the electric side of the vehicle fully functional. With a bit more tinkering on the electric side and through a slight gearing change through tire size, it is anticipated that the car will likely average 100mpg. The build for the car has been documented on the web site and is as close to open source as my time allows. The car was built by two guys in a garage in Southern Maryland. If we can do it I don't see any reason why major auto manufacturers can't do it since we used their parts."
Volkswagen is trying to change that with their Jetta TDI. They ran a bunch of basically infomercials with the Mythbusters guys after each episode for a while trying to "bust the myths" surrounding diesel engines. Time will tell if their marketing campaign is successful, but I would love to see a diesel engine car make some headway here. Personally, I figure I'll be in the market for a new car in 1 or 2 years, and if the Jetta TDI is as good as they want us to think it is, I'm leaning pretty heavily towar
For various reasons the industry in the US has shunned diesel for private vehicles.
Maybe because the public has shunned it?
Let's be honest here, the industry will do what the public wants when the public votes with their dollars. Diesel could be the answer to the problem but it's also perceived as a problem in and of itself with the public. For the industry it will take less for them to build a technology than to dispel the FUD around an old technology.
And even above the FUD it's hard. At least in my case. I was looking into diesel over a decade ago and good information was hard to get. It was a scary beast when I heard the stories of the fuel gelling, the cost of diesel and engine block heaters. Even with all of this what ended up killing it off for me was that I could only find one service station within 5 miles of my house that had diesel. It made me wonder just how hard it would be to fuel my car in a pinch.
Today I would be less apprehensive but given that I have a newish vehicle and in expect to see a swing in the market before I need a new one I guess it's a moot point.
For various reasons the industry in the US has shunned diesel for private vehicles. That has to change before any headway can be made.
Well, the big issue was diesel was much dirtier in North America (high sulfur content) than in Europe, and a lot of the technologies that make diesel cars behave like gas cars tend to require the clean diesel. These days though, I believe the legislation has made low-sulfur diesel mandatory, which is why we see VW and Mercedes starting to import more diesel cars.
Quite a change, really - drive a heavy SUV that gets 5L/100km or better (probably spewing less CO2 than the little car next to you...). Or the fact that the engine lacks the traditional diesel clatter normally associated with trucks, or hell, doesn't Mercedes have a thing that mixes ammonia or something with exhaust that makes the exhaust even cleaner still?
Mercedes uses Urea to deal with the NO2 issue - although Honda was supposed to be using a high-temp plasma to do the same (http://www.autoblog.com/2006/05/27/honda-turning-to-plasma-to-beat-diesel-emmisions/) so you would not need to refill urea/ammonia in the car.
US emissions restrictions are different from Europe. Not necessarily stricter, but different.
As I understand it, US emissions regulations are very strict about particulates and NOx emissions (both drawbacks for diesel. Particulates is easy to solve and has been solved, NOx is much harder.)
Euro emissions regulations are very strict about unburned hydrocarbons IIRC, which is good for diesel but bad for gasoline. They are far less strict about NOx.
For various reasons the industry in the US has shunned diesel for private vehicles. That has to change before any headway can be made.
I disagree. Diesel is a BYPRODUCT of gasoline refining. A barrel of oil (42 US gallons), when refined, yields about 19.5 gallons of gasoline and about 9 gallons of diesel. Part of the reason diesel prices got so expensive last summer is because there was no supply. Nobody was buying the expensive gasoline that accounts for more than half of all refined goods, but the big trucks and ships needed the diesel that nobody wanted to make because they couldn't sell the gasoline. Starting to see the vicious cycle?
Therefore, if a bunch of people started driving diesel cars, you'd see last summer's diesel prices becoming a bit more permanent. Leave diesel to work vehicles. Cars should run on gasoline. The headway needs to be made in technologies like gasoline direct injection.
by Anonymous Coward
on Tuesday August 18, @10:44AM (#29106449)
The black helicopters need to be sent in here. Gas Mileage like that is un-American. Before you know it, the schematics for the water-car will get out.
by Anonymous Coward
on Tuesday August 18, @10:45AM (#29106463)
(whisper)When it comes to cars, the slashdotter species generally has absolutely NO idea what it is talking about. Shhhh. Here comes the posters now. Let's watch quietly as they trot out the same old ignorant meme's about hybrids, electrics and diesels.(/whisper)
By using less fuel you are shifting the tax burden onto those who cannot afford a high tech vehicle. We should expect owners of hybrids, electric cars and high efficiency vehicles to pay their fair share if they can't manage to pay their road tax through fuel purchases. Perhaps you people should be required to keep a log of your travel distances and cut a check when you renew your state registration based on your mileage.
Don't be stupid. I mean, the widening fuel/tax-vs-driving gulf is a legit issue, but if the state wants their road tax money, they're perfectly capable of asking for it. (Demanding, actually). In the meantime, they're giving you a tax break for fuel efficiency, which isn't that bad a thing to do, all told.
And in general, I reject the premise that people are morally obligated to voluntarily donate as great a portion to their income as is feasible to the government (like some of those people who say "you sh
Most states had budget shortfalls this year. Road projects are being deferred or outright canceled. If you don't mind driving over potholes, then keep driving your hybrid/electric/whatever. The pollution a car makes has zero impact on the use of the road. If people should get a break, it's people who drive motorcycles which use far less space on the road. Or compact cars which are lighter and damage the road less.
I'm surprised you didn't point out that I didn't attack bicyclists for not paying any tax at al
I live in a state with one of the highest gasoline taxes in the union, and our gas tax doesn't put a dent in our road maintenance budget, which is already not enough to properly maintain the roads.
Using less gas isn't 'shifting the burden' to those who can't afford a more efficient car, especially since there -are- efficient cheap cars. I bought my small 34 MPG car (on the efficient side for the USA) because I couldn't -afford- anything else.
Your argument tries to use economics as a way to discourage a more
Diesel engines have always been where hybrid cars should go, its just that in North America, most people avoid diesel and gas stations often don't have it.
Diesel engines afaik have always been more tunable to run very efficiently at specific speeds and are therefore a much better choice for generators in general (and are often used in that capacity). Using a fixed-speed diesel engine to generate electricity for a hybrid vehicle seems obvious, and its been done for both city buses and the military HMMV with great success.
I believe a consumer focus on gasoline has lead to car companies' focus on gasoline-electric hybrids instead of diesel-electric.
Except that you're talking about a series hybrid drive, and only the Chevy Volt works that way at the moment.
The Insight and the Prius are both parallel drive hybrids, which means the gas engine turns the wheels as well as powers up the batteries. The electric turns the wheels sometimes. The Volt's big thing is that it's a series hybrid, the drive is always electric and the gas engine runs at its high-efficiency speed to charge the batteries, then shuts off again.
Meaning that your comment would be correct if all hybrids were series hybrids, but as of now your comment would only apply to the Volt which isn't in production yet.
I'm quite certain the Volt is in fact in production [engadget.com] at this point, and yes I'm speaking of series hybrid drives but that doesn't invalidate my point at all.
My point was simply about using hybrid drives at all, and the choice to use parallel hybrid drives for gasoline engines stems precisely from inefficiencies.
As another person replied, a series hybrid will never be more efficient than a straight engine, but that's ignoring the charging of the batteries through third party options like regenerative braking, solar collection and wall sockets.
As another person replied, a series hybrid will never be more efficient than a straight engine, but that's ignoring the charging of the batteries through third party options like regenerative braking, solar collection and wall sockets.
It's also ignoring that the losses through conversion are only in the 5% to 10% range. If the gain from running the engine at a constant speed is enough to offset this loss, the hybrid *will* be more efficient.
Actually, it's just the opposite - due to the fact that they throttle simply by adjusting fuel supply to the cylinders and typically do not have a throttle plate, diesel engines are FAR more efficient at reduced power levels than gasoline engines are.
As a result, one of the two main hybrid advantages (running the engine at peak efficiency) is negated. On the other hand, due to the high compression ratio, diesels are simply more efficient.
The other big hybrid advantage (regenerative braking) is still quite applicable to diesel, and in fact may be far easier to apply to diesels than to gasoline, since "ghetto hybrid" approaches like belt alternator-starter and flywheel alternator-starter can still provide great benefit. (Downshift to rev the engine and get the electric to spin - in a gas engine this will result in engine braking. Diesels don't, and in fact can't without special tricks, engine brake, so having an electric generator tied directly to the engine would still be quite effective.)
The irony is that hybrid diesels would be perfect, but nobody takes the concept to it's true potential. Diesel electric all the way, like in train engines. A Diesel likes to have a constant RPM at it's peak performance value. Imagine connecting an alternator directly to the engine and giving up the inefficient gear system. Imagine a Diesel engine that is always at it's peak performance RPM, even when there's barely any electrical load on it. That car would be a rocket that goes for free (or almost free). It's also pretty easy to build if you have 2 things: 1) 1x 150kW alternator (it's the right amount) that also fits under the hood along with the engine. 2) 4x 40kW electric engines that you connect directly to the drive shaft (and should also fit in there somewhere). As far as I know a 150kW alternator is very big (about as big as the engine itself) and the 40kW engines are also huge, but at least in theory this would be by far the best way to bring the top possible performance of an engine to the tarmac. Electricity is the best way to transfer energy between two points and a constant RPM diesel is the most efficient and performant diesel out there.
Why bother using a drive shaft? Put the 4 eletric motors at the wheels and just run electric wire to power them. Otherwise, I like your idea, it is probably overpowered for the normal driver, but a good idea.
Since the site has been/.'ed and I can't RTFA, I have to ask... Is this really a Diesel Electric engine (as in locomotives) where the diesel engine is used solely to create electricity and is not connected to the drive train? Or is this actually a Diesel Hybrid?
The current model VW's that have diesel options (Jetta, Golf, Beetle) can average 50mpg all day long with 4 adults and the AC turned on. The first generation Honda Insight, by comparison, barely fits two grown adults (no back seat at all), and has a much smaller fuel tank. If they did this with the new Insight (their web page seems to have gone up in smoke so I can't tell which Insight they used) it would be a little more impressive, though they would still be dealing with the technical issues that face hybrids that do no apply to diesel.
I for one would rather start with a diesel and tune it to get 70mpg without a trunk full of batteries.
The main reason gasoline hybrids get better mileage than direct-coupled engines is that the gasoline engine is not forced to operate at inefficient points on its' BSFC map (near closed throttle). The engine only runs when needed, and then it runs near its' BEP (Best efficiency point), or occasionally at maximum power which also has decent efficiency. It is not forced to idle and off-idle conditions where the pumping losses are horrible and efficiency s#x (5x fuel for same marginal power).
Diesel engines have entirely different BSFC maps, and do not suffer the same pumping losses (vacuum across throttle plate). Their drop off at idle is _much_ lower than for gasoline engines, so they're great in city-wide European traffic jams. Diesel fuel also is ~15% denser (more heat per gallon) and the higher compression ratio is about 5% more theoretically efficient.
But a diesel hybrid does not have much to gain by hybridization. The BSFC map is much flatter, and the engine restarting power & wear is considerably higher.
Diesels are more expensive than gas engines. Hybrids are more expensive than non-hybrids. Diesel hybrids are the most expensive of the bunch. The market just isn't willing to pay an extra 8-10k for more efficiency. As it is, hybrid buyers have to wait many years to make up the difference versus similar but non-hybrid cars.
Compare the Honda Fit to the Insight.
Insight Base MSRP 19,800 Fit Base Auto MSRP 15,550 Insight MPG 41 Fit MPG 31
Assume fuel is $4.00 (higher than now) and 15,000 miles driven per year.
So basically, assuming you keep the car, you break even when you've saved 4250 on fuel. That will take 9 years.
So say you take the 50MPG diesel and turn it into a 66MPG diesel. The amount spent on fuel each year will be much smaller in the first place, so it will take even longer to pay off the investment.
If you follow that link and look at the gas-pump shaped chart on the right you will see that Diesel has far higher taxes imposed on it than Gasoline, or put another way Gasoline is subsidized through lower taxes than Diesel. And still Diesel averages only a couple of pennies per gallon more expensive.
And even according to the current price listed on the linked website, diesel is currently cheaper. Not to mention the MPG savings, so if you do it cost per mile, diesel is much cheaper...
The newest diesel engines, because of California, now emit much less particulate than even last years engines (however still more than gas). Also NO2 is much reduced for the same reasons.
I'm not saying this one isn't gutless. But current diesel technology allows for some serious horsepower and the acceleration of some vehicles I have been in are on par with other vehicles of their size.
Unfortunately Diesel has a bad name. Partly because many gutless vehicles were made with it. I'd like to know this vehicles specs so I'm off to RTFA.
No, modern diesels are nothing like the anemic POS that GM released in the 70s. Mainly because of the addition of the turbo charger (which diesels benefit greatly from), but common rail, higher injection pressures, advances in metallurgy.
My TDI is quite peppy, mainly because the shape of the torque curve. BMW has a 335d and X5 which they are selling here now. VW and Benz have been selling diesels here almost non-stop since the 70s.
That's why I always laugh when Chevy's ads come on trying to sell me this AMAZING 29 MPG car.
I got 48 MPG in a '86 IDI Diesel (that was a bit weak, but who needs more than 50 HP?) I get 45 MPG in a '98 TDI diesel that is quite peppy. I have upgraded injectors and a special chip tune. I bet I'm just barely over 110 HP, if that.
All diesels in the 70s where gutless. Heck simple truth was all cars in the US in the 70s where pretty gutless. The 70s was when we where trying to get emission controls to work and computers for controlling fuel injection and spark where primitive or just not available. GM got such a bad rap on the diesel and for the most part it was unfair. The GM diesel where sold to people that didn't know how to maintain them and by dealers that really didn't know how to maintain them. People that bought a 300D where us
Heck simple truth was all cars in the US in the 70s where pretty gutless.
Okay, this is more about aerodynamics than being gutless but whatever...
I had a 76 Ford Pinto when I was a teenager. My friend and I were on our way up to White Pass to go skiing when some guy in a Dodge Charger goes flying around us at ~ 90mph on a blind curve. Fortunately no one was coming the other way, but a cop was sitting right there. He pulls the guy over, then (as I drove by) flagged me down as well. The cop walks up to me and says "I have the two of you doing 90+ on this mountain road", to which I replied with the truth - I'd been passed on a curve, and may have been right behind the Charger but was not going that fast (probably 55-60, which was within the limit). He give me one of those "I've heard THAT before" looks, so I followed up with "Have you ever been in a Ford Pinto going over 65mph? The thing shakes so hard it'd probably start to fall apart pretty fast".
All diesels in the 70s where gutless. Heck simple truth was all cars in the US in the 70s where pretty gutless. The 70s was when we where trying to get emission controls to work and computers for controlling fuel injection and spark where primitive or just not available.
This is true. The basic scientific research on how to control automobile exhaust emissions was incomplete at the time, and the engine controls available were too primitive. This isn't anyone's fault - technology just hadn't caught up to the needs of the time. The only way to do it was to lower compression ratios, and reduce the camshaft profiles. The pellet-bed catalytic converters of the time were horribly restrictive also. About the only good thing that happened to car engines in the 1970s was the advent of good electronic ignition systems.
Turbochargers were not in wide use (or production) for cars, so there were very few turbodiesel cars (mostly MB) due to the cost of the turbo itself. Normally aspirated diesels aren't exactly exciting to drive. (Trivia - when the Porsche 911 Turbo came out, parts of the turbo system were made by Lycoming, the aircraft engine company, because there weren't any suitable automotive turbo parts available.)
GM got such a bad rap on the diesel and for the most part it was unfair.
That's not totally true. There were some basic design mistakes, and a cost cutting decision you mentioned that were the downfall of the Oldsmobile diesel.
The GM diesel where sold to people that didn't know how to maintain them and by dealers that really didn't know how to maintain them. People that bought a 300D where used to paying Hans the big bucks. Olds buyers where not.
Actually, a Mercedes diesel of the time required very little maintenance (on the engine at least). Oil, coolant and filter (air/fuel/oil) changes, and that's about it. You could do it all in your driveway.
Also GM didn't put in a water separator. That was shouldn't have been an issue but right then quality of diesel went to crap and you had a lot of failed injector pumps.
Again MB was used to crap fuel and put in the extra filtering needed.
This was a big problem. All diesel fuel accumulates water eventually. Diesel fuel has a lubricity requirement - because it must also lubricate the high pressure injection pump. Water is not a good lubricant. Leaving out the water separator was a cost cutting decision GM would not repeat. The later Chevrolet (designed in collaboration with Detroit Diesel) 6.2/6.5 V8 came with one, and even a warning light on the dash to indicate that there was a buildup of water in the fuel (you would then have to open a valve and drain the water out of the separator.
The problems weren't all maintenance-related. The GM 350 diesel (and the lesser-known 4.3V6 diesel used in the front-wheel-drive A-body cars, unrelated to the later Chevrolet 4.3 gas V6) was designed by reusing parts from the Oldsmobile gas V8. The blocks were made using a high-nickel iron alloy and are very strong - they're often bought from the junkyards by drag racers who want to use them as the basis to build very high powered gas engines. The cylinder heads and crankshafts were pretty much stretching the design limits of the materials they were made of, since they were designed under budget constraints. Cracked heads and broken crankshafts were not uncommon. There are tolerances in the alloy compositions (this is just a fact of life, not a GM problem) - because of this some engines got stronger crankshafts and cylinder heads (basically by chance), and there are quite a few 5.7 diesels still running around. I have a friend who was driving a 1980 Oldsmobile 98 Diesel until a few years ago when the body started to rust out.
The later 6.2/6.5 engines were very durable, because they were designed from the ground up to be diesels.
It is unfortunate that GMs design errors stained the diesel in the US
The GM diesel where sold to people that didn't know how to maintain them and by dealers that really didn't know how to maintain them. People that bought a 300D where used to paying Hans the big bucks.
My dad's 300D from 1982 has never required any sort of engine work. It's driven 300k miles on diesel and now 100k on vegetable oil. It's got the original transmission, the original suspension, the original brakes (this seems crazy to me, but they're in fine shape), etc. It doesn't have the original battery, filters have been replaced, and the vacuum system that controls the locks is leaky so if you shut down the car and lock/unlock cycle the doors a few times the other 3 doors will stop following the driver's door lock.
His 1994 Ford Explorer gets a new transmission every ~4 years, new brakes every 1.5 years, and required him to work on the engine for a week a few years ago. The brakes and transmission are no longer Ford parts - those failed even more often and the new brand has a lifetime warranty that gets a lot of use. The front suspension needed to be replaced, and when the brakes fail ahead of schedule (they do so by falling off while you're driving if you don't watch them closely enough to catch them a month in advance) there's a good chance you'll cause some damage requiring replacement of the axle if you have to tap the brake pedal as you get off the road.
Anecdotes, but along with similar experiences on 2 other Mercedes and 3 other American cars in this period, they're enough to make him look to the Germans when he wants a new car.
I've also got a 2003 VW Golf TDI, thing's a blast. It's not a barn burner in a straight line but that doesn't mean you can't do that. Down in Holt raceway we had a guy that'd bring out his F-250 diesel and burn straight kerosene. It was a 1/8mi. track and he smoked *everything*. Funniest thing I'd seen.
But yeah, modern diesels are fantastic. Fuel efficient, plenty of punch, stupid amounts of torque, and best of all diesel's extremely durable and simple which makes it ideal for consumer vehicles. My wife's a diesel mechanic (buses mostly) and trust me you can beat the tar out of a diesel and it'll probably still outlive you.
I recently traded my 06 VW Golf TDI in on a new Camaro. Let me tell you, a diesel is far from gutless. Thanks to the low end torque of diesel the car accelerates more like a small V6 instead of a I4. I could comfortable cruise at 80 mph which is 5 over the speed limit on the highway by me. When it comes to automotive performance, horsepower determines top speed and torque acceleration.
If I get to the point that I can afford a 2nd car payment or pay off my new car another VW TDI will be at the top of my
TDI = Turbo Direct Injection (Fuel is injected straight into the cylinders) SDI = Stratified Diesel Injection. (Same as above, no turbo). IDI = Indirect Injector. (Fuel is injected into prechamber.) Came with and without a turbo.
Comparing the two formulae it can be seen that for a given compression ratio (r), the ideal Otto cycle will be more efficient. However, a diesel engine will be more efficient overall since it will have the ability to operate at higher compression ratios. If a petrol engine were to have the same compression ratio, then knocking (self-ignition) would occur and this would severely reduce the efficiency, whereas in a diesel engine, the self ignition is the desired behavior. Additionally, both of these cycles are only idealizations, and the actual behavior does not divide as clearly or sharply. And the ideal Otto cycle formula stated above does not include throttling losses, which do not apply to diesel engines.
Using the diesel cycle with other fuels has gotten >50% thermal efficiency in the lab, which is DAMN good IMHO.
For example, a typical gasoline automobile engine operates at around 25% efficiency, and a large coal-fueled electrical generating plant peaks at about 46%. The largest diesel engine in the world peaks at 51.7%. In a combined cycle plant, thermal efficiencies are approaching 60%.
> Back when Volvo first released their diesel intercooled turbo's here in North America, people were stepping on the gas and wrapping them around trees,
> So no, they're not gutless. If you can get an S70 made before '98 you're in for a happy surprise too.
Frankly, it has been my experience that if you truly know what you're doing, you can generally carry a bigger price tag for your work. You spend less time doing it, and can do more, or at least more complex. Someone that is cheaper generally doesn't know quite as much, so spends longer to do it, and doesn't have the experience already built up not to screw it up in the process. That experience is a big benefit. There are of course exceptions for those that know what they're doing selling themselves cheaply, but I don't think that's typical.
Having worked at a manufacturing facility once already, supporting their IT Ops, I fail to see why a 'highly paid employee in training' is a negative. IT is often sent to training, and I would hazard a guess that they're often paid more than the assembler on the floor. In my particular case, assemblers were also sent to training in order to assert the value of Standard Work. This would enhance effectiveness of the assemblers by simplifying and streamlining the process and empowering them to make suggestions as to how the process could be done more efficiently. Considering this plant was always falling behind on their quota due to inefficiencies, having workers that know how to speed up the process is of significant value, and that means more money for the company.
Also, a manufacturing method that requires fewer workers doesn't mean that jobs will always be cut. Perhaps a second production line will be opened instead, allowing the factory to produce more with their highly paid, highly trained workforce? Other factors, such as penny pinching and trying to get employees to do more with less often set up the scenario where strikes would happen, or employees feel disgruntled and leave for other opportunities.
Isn't it a feature of diesels that they run best in a narrow RPM range?
That's a characteristic of ALL internal combustion engines, not just diesels. The reason it has been associated with diesels is that the common applications of diesels are those that lend themselves to narrow-range or constant rpm applications like trucks and diesel-electric trains. You could easily optimize a gasoline or methanol engine for a particular RPM range wtih similar results - a restrictor plate NASCAR motor being a hallmark example. It jusy runs around at an almost constant RPM the entire race, and it highly optimized for both power and mileage.
Because .. (Score:3, Insightful)
Re: (Score:3, Interesting)
Re:Because .. (Score:4, Insightful)
Maybe because the public has shunned it?
Let's be honest here, the industry will do what the public wants when the public votes with their dollars. Diesel could be the answer to the problem but it's also perceived as a problem in and of itself with the public. For the industry it will take less for them to build a technology than to dispel the FUD around an old technology.
And even above the FUD it's hard. At least in my case. I was looking into diesel over a decade ago and good information was hard to get. It was a scary beast when I heard the stories of the fuel gelling, the cost of diesel and engine block heaters. Even with all of this what ended up killing it off for me was that I could only find one service station within 5 miles of my house that had diesel. It made me wonder just how hard it would be to fuel my car in a pinch.
Today I would be less apprehensive but given that I have a newish vehicle and in expect to see a swing in the market before I need a new one I guess it's a moot point.
Parent
Re:Because .. (Score:5, Informative)
Well, the big issue was diesel was much dirtier in North America (high sulfur content) than in Europe, and a lot of the technologies that make diesel cars behave like gas cars tend to require the clean diesel. These days though, I believe the legislation has made low-sulfur diesel mandatory, which is why we see VW and Mercedes starting to import more diesel cars.
Quite a change, really - drive a heavy SUV that gets 5L/100km or better (probably spewing less CO2 than the little car next to you...). Or the fact that the engine lacks the traditional diesel clatter normally associated with trucks, or hell, doesn't Mercedes have a thing that mixes ammonia or something with exhaust that makes the exhaust even cleaner still?
Parent
Re:Because .. (Score:4, Informative)
Parent
Re: (Score:3, Informative)
The main reason is the EPA.
US emissions restrictions are different from Europe. Not necessarily stricter, but different.
As I understand it, US emissions regulations are very strict about particulates and NOx emissions (both drawbacks for diesel. Particulates is easy to solve and has been solved, NOx is much harder.)
Euro emissions regulations are very strict about unburned hydrocarbons IIRC, which is good for diesel but bad for gasoline. They are far less strict about NOx.
Re:Because .. (Score:4, Interesting)
For various reasons the industry in the US has shunned diesel for private vehicles. That has to change before any headway can be made.
I disagree. Diesel is a BYPRODUCT of gasoline refining. A barrel of oil (42 US gallons), when refined, yields about 19.5 gallons of gasoline and about 9 gallons of diesel. Part of the reason diesel prices got so expensive last summer is because there was no supply. Nobody was buying the expensive gasoline that accounts for more than half of all refined goods, but the big trucks and ships needed the diesel that nobody wanted to make because they couldn't sell the gasoline. Starting to see the vicious cycle? Therefore, if a bunch of people started driving diesel cars, you'd see last summer's diesel prices becoming a bit more permanent. Leave diesel to work vehicles. Cars should run on gasoline. The headway needs to be made in technologies like gasoline direct injection.
Parent
Something's wrong with this idea (Score:5, Funny)
The black helicopters need to be sent in here. Gas Mileage like that is un-American. Before you know it, the schematics for the water-car will get out.
Today on mutual of slashomaha... (Score:5, Funny)
(whisper)When it comes to cars, the slashdotter species generally has absolutely NO idea what it is talking about. Shhhh. Here comes the posters now. Let's watch quietly as they trot out the same old ignorant meme's about hybrids, electrics and diesels.(/whisper)
Re: (Score:3, Interesting)
Please pay your taxes in full (Score:5, Funny)
By using less fuel you are shifting the tax burden onto those who cannot afford a high tech vehicle. We should expect owners of hybrids, electric cars and high efficiency vehicles to pay their fair share if they can't manage to pay their road tax through fuel purchases. Perhaps you people should be required to keep a log of your travel distances and cut a check when you renew your state registration based on your mileage.
Re: (Score:3, Insightful)
And in general, I reject the premise that people are morally obligated to voluntarily donate as great a portion to their income as is feasible to the government (like some of those people who say "you sh
Re: (Score:3, Interesting)
Most states had budget shortfalls this year. Road projects are being deferred or outright canceled. If you don't mind driving over potholes, then keep driving your hybrid/electric/whatever. The pollution a car makes has zero impact on the use of the road. If people should get a break, it's people who drive motorcycles which use far less space on the road. Or compact cars which are lighter and damage the road less.
I'm surprised you didn't point out that I didn't attack bicyclists for not paying any tax at al
Re: (Score:3, Interesting)
I live in a state with one of the highest gasoline taxes in the union, and our gas tax doesn't put a dent in our road maintenance budget, which is already not enough to properly maintain the roads.
Using less gas isn't 'shifting the burden' to those who can't afford a more efficient car, especially since there -are- efficient cheap cars. I bought my small 34 MPG car (on the efficient side for the USA) because I couldn't -afford- anything else.
Your argument tries to use economics as a way to discourage a more
Diesel is so obviously better for hybrids (Score:5, Insightful)
Diesel engines have always been where hybrid cars should go, its just that in North America, most people avoid diesel and gas stations often don't have it.
Diesel engines afaik have always been more tunable to run very efficiently at specific speeds and are therefore a much better choice for generators in general (and are often used in that capacity). Using a fixed-speed diesel engine to generate electricity for a hybrid vehicle seems obvious, and its been done for both city buses and the military HMMV with great success.
I believe a consumer focus on gasoline has lead to car companies' focus on gasoline-electric hybrids instead of diesel-electric.
Re:Diesel is so obviously better for hybrids (Score:5, Informative)
Except that you're talking about a series hybrid drive, and only the Chevy Volt works that way at the moment.
The Insight and the Prius are both parallel drive hybrids, which means the gas engine turns the wheels as well as powers up the batteries. The electric turns the wheels sometimes. The Volt's big thing is that it's a series hybrid, the drive is always electric and the gas engine runs at its high-efficiency speed to charge the batteries, then shuts off again.
Meaning that your comment would be correct if all hybrids were series hybrids, but as of now your comment would only apply to the Volt which isn't in production yet.
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Re:Diesel is so obviously better for hybrids (Score:4, Interesting)
I'm quite certain the Volt is in fact in production [engadget.com] at this point, and yes I'm speaking of series hybrid drives but that doesn't invalidate my point at all.
My point was simply about using hybrid drives at all, and the choice to use parallel hybrid drives for gasoline engines stems precisely from inefficiencies.
As another person replied, a series hybrid will never be more efficient than a straight engine, but that's ignoring the charging of the batteries through third party options like regenerative braking, solar collection and wall sockets.
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Re:Diesel is so obviously better for hybrids (Score:4, Interesting)
As another person replied, a series hybrid will never be more efficient than a straight engine, but that's ignoring the charging of the batteries through third party options like regenerative braking, solar collection and wall sockets.
It's also ignoring that the losses through conversion are only in the 5% to 10% range. If the gain from running the engine at a constant speed is enough to offset this loss, the hybrid *will* be more efficient.
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Re:Diesel is so obviously better for hybrids (Score:4, Informative)
Actually, it's just the opposite - due to the fact that they throttle simply by adjusting fuel supply to the cylinders and typically do not have a throttle plate, diesel engines are FAR more efficient at reduced power levels than gasoline engines are.
As a result, one of the two main hybrid advantages (running the engine at peak efficiency) is negated. On the other hand, due to the high compression ratio, diesels are simply more efficient.
The other big hybrid advantage (regenerative braking) is still quite applicable to diesel, and in fact may be far easier to apply to diesels than to gasoline, since "ghetto hybrid" approaches like belt alternator-starter and flywheel alternator-starter can still provide great benefit. (Downshift to rev the engine and get the electric to spin - in a gas engine this will result in engine braking. Diesels don't, and in fact can't without special tricks, engine brake, so having an electric generator tied directly to the engine would still be quite effective.)
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Re:Diesel is so obviously better for hybrids (Score:5, Interesting)
The irony is that hybrid diesels would be perfect, but nobody takes the concept to it's true potential.
Diesel electric all the way, like in train engines. A Diesel likes to have a constant RPM at it's peak performance value. Imagine connecting an alternator directly to the engine and giving up the inefficient gear system. Imagine a Diesel engine that is always at it's peak performance RPM, even when there's barely any electrical load on it. That car would be a rocket that goes for free (or almost free). It's also pretty easy to build if you have 2 things:
1) 1x 150kW alternator (it's the right amount) that also fits under the hood along with the engine.
2) 4x 40kW electric engines that you connect directly to the drive shaft (and should also fit in there somewhere).
As far as I know a 150kW alternator is very big (about as big as the engine itself) and the 40kW engines are also huge, but at least in theory this would be by far the best way to bring the top possible performance of an engine to the tarmac. Electricity is the best way to transfer energy between two points and a constant RPM diesel is the most efficient and performant diesel out there.
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Re:Diesel is so obviously better for hybrids (Score:4, Interesting)
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Diesel Hybrid? (Score:4, Interesting)
I'm not all that impressed (Score:3, Interesting)
I for one would rather start with a diesel and tune it to get 70mpg without a trunk full of batteries.
Can't capture the same benefit twice (Score:5, Interesting)
The main reason gasoline hybrids get better mileage than direct-coupled engines is that the gasoline engine is not forced to operate at inefficient points on its' BSFC map (near closed throttle). The engine only runs when needed, and then it runs near its' BEP (Best efficiency point), or occasionally at maximum power which also has decent efficiency. It is not forced to idle and off-idle conditions where the pumping losses are horrible and efficiency s#x (5x fuel for same marginal power).
Diesel engines have entirely different BSFC maps, and do not suffer the same pumping losses (vacuum across throttle plate). Their drop off at idle is _much_ lower than for gasoline engines, so they're great in city-wide European traffic jams. Diesel fuel also is ~15% denser (more heat per gallon) and the higher compression ratio is about 5% more theoretically efficient.
But a diesel hybrid does not have much to gain by hybridization. The BSFC map is much flatter, and the engine restarting power & wear is considerably higher.
Re: (Score:3, Insightful)
Which is of course why we see gasoline electric locomotives all over the place ...
EPA (Score:3, Interesting)
> If we can do it I don't see any reason why major auto manufacturers can't do
> it...
Have your car's emissions tested.
Diesel + Hybrid = Expensive (Score:5, Informative)
Diesels are more expensive than gas engines. Hybrids are more expensive than non-hybrids. Diesel hybrids are the most expensive of the bunch. The market just isn't willing to pay an extra 8-10k for more efficiency. As it is, hybrid buyers have to wait many years to make up the difference versus similar but non-hybrid cars.
Compare the Honda Fit to the Insight.
Insight Base MSRP 19,800
Fit Base Auto MSRP 15,550
Insight MPG 41
Fit MPG 31
Assume fuel is $4.00 (higher than now) and 15,000 miles driven per year.
So basically, assuming you keep the car, you break even when you've saved 4250 on fuel. That will take 9 years.
So say you take the 50MPG diesel and turn it into a 66MPG diesel. The amount spent on fuel each year will be much smaller in the first place, so it will take even longer to pay off the investment.
Re:Frankly I Recommend Such Things (Score:4, Informative)
significantly cheaper at the pump
I don't think that's correct. [doe.gov]
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Re:Frankly I Recommend Such Things (Score:5, Informative)
If you follow that link and look at the gas-pump shaped chart on the right you will see that Diesel has far higher taxes imposed on it than Gasoline, or put another way Gasoline is subsidized through lower taxes than Diesel. And still Diesel averages only a couple of pennies per gallon more expensive.
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Re: (Score:3, Informative)
Re: (Score:3, Informative)
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I'm not saying this one isn't gutless. But current diesel technology allows for some serious horsepower and the acceleration of some vehicles I have been in are on par with other vehicles of their size.
Unfortunately Diesel has a bad name. Partly because many gutless vehicles were made with it. I'd like to know this vehicles specs so I'm off to RTFA.
Re:Gutless? (Score:5, Informative)
No, modern diesels are nothing like the anemic POS that GM released in the 70s. Mainly because of the addition of the turbo charger (which diesels benefit greatly from), but common rail, higher injection pressures, advances in metallurgy.
My TDI is quite peppy, mainly because the shape of the torque curve. BMW has a 335d and X5 which they are selling here now. VW and Benz have been selling diesels here almost non-stop since the 70s.
That's why I always laugh when Chevy's ads come on trying to sell me this AMAZING 29 MPG car.
I got 48 MPG in a '86 IDI Diesel (that was a bit weak, but who needs more than 50 HP?)
I get 45 MPG in a '98 TDI diesel that is quite peppy. I have upgraded injectors and a special chip tune. I bet I'm just barely over 110 HP, if that.
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Re: (Score:3, Informative)
All diesels in the 70s where gutless. Heck simple truth was all cars in the US in the 70s where pretty gutless. The 70s was when we where trying to get emission controls to work and computers for controlling fuel injection and spark where primitive or just not available.
GM got such a bad rap on the diesel and for the most part it was unfair.
The GM diesel where sold to people that didn't know how to maintain them and by dealers that really didn't know how to maintain them. People that bought a 300D where us
Re:Gutless? (Score:5, Funny)
Heck simple truth was all cars in the US in the 70s where pretty gutless.
Okay, this is more about aerodynamics than being gutless but whatever...
I had a 76 Ford Pinto when I was a teenager. My friend and I were on our way up to White Pass to go skiing when some guy in a Dodge Charger goes flying around us at ~ 90mph on a blind curve. Fortunately no one was coming the other way, but a cop was sitting right there. He pulls the guy over, then (as I drove by) flagged me down as well. The cop walks up to me and says "I have the two of you doing 90+ on this mountain road", to which I replied with the truth - I'd been passed on a curve, and may have been right behind the Charger but was not going that fast (probably 55-60, which was within the limit). He give me one of those "I've heard THAT before" looks, so I followed up with "Have you ever been in a Ford Pinto going over 65mph? The thing shakes so hard it'd probably start to fall apart pretty fast".
He laughed and let me go.
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The real story (Score:5, Insightful)
All diesels in the 70s where gutless. Heck simple truth was all cars in the US in the 70s where pretty gutless. The 70s was when we where trying to get emission controls to work and computers for controlling fuel injection and spark where primitive or just not available.
This is true. The basic scientific research on how to control automobile exhaust emissions was incomplete at the time, and the engine controls available were too primitive. This isn't anyone's fault - technology just hadn't caught up to the needs of the time. The only way to do it was to lower compression ratios, and reduce the camshaft profiles. The pellet-bed catalytic converters of the time were horribly restrictive also. About the only good thing that happened to car engines in the 1970s was the advent of good electronic ignition systems. Turbochargers were not in wide use (or production) for cars, so there were very few turbodiesel cars (mostly MB) due to the cost of the turbo itself. Normally aspirated diesels aren't exactly exciting to drive. (Trivia - when the Porsche 911 Turbo came out, parts of the turbo system were made by Lycoming, the aircraft engine company, because there weren't any suitable automotive turbo parts available.)
GM got such a bad rap on the diesel and for the most part it was unfair.
That's not totally true. There were some basic design mistakes, and a cost cutting decision you mentioned that were the downfall of the Oldsmobile diesel.
The GM diesel where sold to people that didn't know how to maintain them and by dealers that really didn't know how to maintain them. People that bought a 300D where used to paying Hans the big bucks. Olds buyers where not.
Actually, a Mercedes diesel of the time required very little maintenance (on the engine at least). Oil, coolant and filter (air/fuel/oil) changes, and that's about it. You could do it all in your driveway.
Also GM didn't put in a water separator. That was shouldn't have been an issue but right then quality of diesel went to crap and you had a lot of failed injector pumps. Again MB was used to crap fuel and put in the extra filtering needed.
This was a big problem. All diesel fuel accumulates water eventually. Diesel fuel has a lubricity requirement - because it must also lubricate the high pressure injection pump. Water is not a good lubricant. Leaving out the water separator was a cost cutting decision GM would not repeat. The later Chevrolet (designed in collaboration with Detroit Diesel) 6.2/6.5 V8 came with one, and even a warning light on the dash to indicate that there was a buildup of water in the fuel (you would then have to open a valve and drain the water out of the separator.
The problems weren't all maintenance-related. The GM 350 diesel (and the lesser-known 4.3V6 diesel used in the front-wheel-drive A-body cars, unrelated to the later Chevrolet 4.3 gas V6) was designed by reusing parts from the Oldsmobile gas V8. The blocks were made using a high-nickel iron alloy and are very strong - they're often bought from the junkyards by drag racers who want to use them as the basis to build very high powered gas engines. The cylinder heads and crankshafts were pretty much stretching the design limits of the materials they were made of, since they were designed under budget constraints. Cracked heads and broken crankshafts were not uncommon. There are tolerances in the alloy compositions (this is just a fact of life, not a GM problem) - because of this some engines got stronger crankshafts and cylinder heads (basically by chance), and there are quite a few 5.7 diesels still running around. I have a friend who was driving a 1980 Oldsmobile 98 Diesel until a few years ago when the body started to rust out.
The later 6.2/6.5 engines were very durable, because they were designed from the ground up to be diesels.
It is unfortunate that GMs design errors stained the diesel in the US
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Re:Gutless? (Score:4, Interesting)
The GM diesel where sold to people that didn't know how to maintain them and by dealers that really didn't know how to maintain them. People that bought a 300D where used to paying Hans the big bucks.
My dad's 300D from 1982 has never required any sort of engine work. It's driven 300k miles on diesel and now 100k on vegetable oil. It's got the original transmission, the original suspension, the original brakes (this seems crazy to me, but they're in fine shape), etc. It doesn't have the original battery, filters have been replaced, and the vacuum system that controls the locks is leaky so if you shut down the car and lock/unlock cycle the doors a few times the other 3 doors will stop following the driver's door lock.
His 1994 Ford Explorer gets a new transmission every ~4 years, new brakes every 1.5 years, and required him to work on the engine for a week a few years ago. The brakes and transmission are no longer Ford parts - those failed even more often and the new brand has a lifetime warranty that gets a lot of use. The front suspension needed to be replaced, and when the brakes fail ahead of schedule (they do so by falling off while you're driving if you don't watch them closely enough to catch them a month in advance) there's a good chance you'll cause some damage requiring replacement of the axle if you have to tap the brake pedal as you get off the road.
Anecdotes, but along with similar experiences on 2 other Mercedes and 3 other American cars in this period, they're enough to make him look to the Germans when he wants a new car.
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Re:Gutless? (Score:4, Insightful)
But yeah, modern diesels are fantastic. Fuel efficient, plenty of punch, stupid amounts of torque, and best of all diesel's extremely durable and simple which makes it ideal for consumer vehicles. My wife's a diesel mechanic (buses mostly) and trust me you can beat the tar out of a diesel and it'll probably still outlive you.
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Re: (Score:3, Interesting)
If I get to the point that I can afford a 2nd car payment or pay off my new car another VW TDI will be at the top of my
Re: (Score:3, Informative)
TDI = Turbo Direct Injection (Fuel is injected straight into the cylinders)
SDI = Stratified Diesel Injection. (Same as above, no turbo).
IDI = Indirect Injector. (Fuel is injected into prechamber.) Came with and without a turbo.
Re:Gutless? (Score:5, Informative)
Arco Gas Station down the street from my house - Regular 87 Octane - 3.05/g diesel 2.85/g
this is in Southern California.
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Re: (Score:3, Interesting)
Diesel IS more efficient.
http://en.wikipedia.org/wiki/Diesel_cycle [wikipedia.org]
http://en.wikipedia.org/wiki/Four-stroke_engine#The_Otto_cycle [wikipedia.org]
Comparing the two formulae it can be seen that for a given compression ratio (r), the ideal Otto cycle will be more efficient. However, a diesel engine will be more efficient overall since it will have the ability to operate at higher compression ratios. If a petrol engine were to have the same compression ratio, then knocking (self-ignition) would occur and this would severely reduce the efficiency, whereas in a diesel engine, the self ignition is the desired behavior. Additionally, both of these cycles are only idealizations, and the actual behavior does not divide as clearly or sharply. And the ideal Otto cycle formula stated above does not include throttling losses, which do not apply to diesel engines.
Using the diesel cycle with other fuels has gotten >50% thermal efficiency in the lab, which is DAMN good IMHO.
http://www.eurekalert.org/pub_releases/2009-08/uow-ga073109.php [eurekalert.org]
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Um. Maybe you should google that. Carnot is 0<=n<=1 (theoretically). Last I checked .51http://en.wikipedia.org/wiki/Carnot_cycle
http://en.wikipedia.org/wiki/Thermal_efficiency [wikipedia.org]
http://en.wikipedia.org/wiki/Carnot_heat_engine [wikipedia.org]
For example, a typical gasoline automobile engine operates at around 25% efficiency, and a large coal-fueled electrical generating plant peaks at about 46%. The largest diesel engine in the world peaks at 51.7%. In a combined cycle plant, thermal efficiencies are approaching 60%.
Re: (Score:3, Insightful)
Diesels still don't put down a ton of horsepower...
What's a ton? My daily driver [fordvehicles.com] is cranking out about 400 HP. It came from the factory at around 325.
Re:Gutless? (Score:4, Funny)
> So no, they're not gutless. If you can get an S70 made before '98 you're in for a happy surprise too.
Like being in a car that's wrapped around a tree?
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Re:two words to explain why not ... (Score:4, Insightful)
If we can do it I don't see any reason why major auto manufacturers can't do it since we used their parts
profit margin
fixed that for you.
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Really? (Score:5, Insightful)
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Re:Really? (Score:4, Insightful)
That's an interesting slippery slope argument.
Frankly, it has been my experience that if you truly know what you're doing, you can generally carry a bigger price tag for your work. You spend less time doing it, and can do more, or at least more complex. Someone that is cheaper generally doesn't know quite as much, so spends longer to do it, and doesn't have the experience already built up not to screw it up in the process. That experience is a big benefit. There are of course exceptions for those that know what they're doing selling themselves cheaply, but I don't think that's typical.
Having worked at a manufacturing facility once already, supporting their IT Ops, I fail to see why a 'highly paid employee in training' is a negative. IT is often sent to training, and I would hazard a guess that they're often paid more than the assembler on the floor. In my particular case, assemblers were also sent to training in order to assert the value of Standard Work. This would enhance effectiveness of the assemblers by simplifying and streamlining the process and empowering them to make suggestions as to how the process could be done more efficiently. Considering this plant was always falling behind on their quota due to inefficiencies, having workers that know how to speed up the process is of significant value, and that means more money for the company.
Also, a manufacturing method that requires fewer workers doesn't mean that jobs will always be cut. Perhaps a second production line will be opened instead, allowing the factory to produce more with their highly paid, highly trained workforce? Other factors, such as penny pinching and trying to get employees to do more with less often set up the scenario where strikes would happen, or employees feel disgruntled and leave for other opportunities.
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Re:MPG no longer relevant (Score:5, Funny)
That's right. MP4 took over.
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Re:Isn't it a feature of diesels that... (Score:4, Informative)
That's a characteristic of ALL internal combustion engines, not just diesels. The reason it has been associated with diesels is that the common applications of diesels are those that lend themselves to narrow-range or constant rpm applications like trucks and diesel-electric trains. You could easily optimize a gasoline or methanol engine for a particular RPM range wtih similar results - a restrictor plate NASCAR motor being a hallmark example. It jusy runs around at an almost constant RPM the entire race, and it highly optimized for both power and mileage.
Brett
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