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Toyota Prius Under Fire For Patent Infringement 504

tekiegreg writes "According to Auto Service World, Toyota (and possibly other hybrid companies) are guilty of violating a patent with their Prius hybrid Systems. The patent in particular looks like it covers most of how the drive-train and even the braking system of a Toyota Prius functions. The implications of which are big if there is no deal or settlement made (such as ceasing of hybrid vehicles in the United States)."
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Toyota Prius Under Fire For Patent Infringement

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  • Diagram (Score:5, Informative)

    by eldavojohn ( 898314 ) * <eldavojohn&gmail,com> on Friday January 13, 2006 @08:39AM (#14462469) Journal
    So if you want a visual of what they're actually talking about, look here [] because that damned patent site refers to images that are nowhere to be found. I think that linked diagram refers to the numbers that the patent information initially state about the design of it.
  • by cdrudge ( 68377 ) * on Friday January 13, 2006 @08:40AM (#14462479) Homepage
    "According to Auto Service World, Toyota (and possibly other hybrid companies)
    The article mentions no other hybrid companies. The only companies mentioned are either Solomon Technologies, the patent holder, and various different divisions of Toyota. The "and possibly other hybrid companies" is just pure speculation.

    are guilty of violating a patent with their Prius hybrid Systems.
    The article just says that Solomon is taking their complaint to the ITC to block Toyota from importing more vehicles. ITC can't rule guilt or fine Toyota. If Toyota manufactured the vehicles here, it likely would circumvent anything the ITC could do. There has been no admission of guilt by Toyota so the only other place guilt can be determined is in a court of law. Until the case currently in US District Court is ruled on, there is no guilt. Only accusations.

    The implications of which are big if there is no deal or settlement made (such as ceasing of hybrid vehicles in the United States)."
    No. In the case of the article it just would mean Toyota couldn't import hybrid vehicles of this design (presuming they don't license the patent and settle the District Court case). They would either have to make them state-side or find a different design. Beleive it or not, there is more then one way to design a hybrid vehicle. This ruling wouldn't have an immediate effect on other manufacturers of hybrid vehicles although it might set a precident for future litigation.
  • by sphealey ( 2855 ) on Friday January 13, 2006 @08:47AM (#14462502)
    > Unfortunately, I think reclaiming breaking
    > energy with an electric motor was thought of,
    > and used much earlier then that.

    Around 1870 in fact.

  • by Gordonjcp ( 186804 ) on Friday January 13, 2006 @08:55AM (#14462524) Homepage
    "Diesel Traction - A Manual for Enginemen", Copyright 1962 by the British Transport Commission, describes using regenerative braking where you use the traction motors in diesel-electric power cars as generators, feeding the current into banks of resistors bolted to the chassis. Somewhere around page 160-odd, about the bit where it's talking about wheel slip detection circuits and stuff.

    I know I saw Telma [] retarders on buses, long before 1990. They work on the same principle.

  • Re:The patent (Score:5, Informative)

    by panthro ( 552708 ) <mavrinac@g[ ] ['mai' in gap]> on Friday January 13, 2006 @08:56AM (#14462530) Homepage

    Yes, and yes. The thing in question here is Toyota's Power Split Device [], which is a constantly-engaged planetary gear set that acts as a transmission and drives (or is partially driven by) the electric motor/generator. Which appears to be exactly what the patent describes.

  • by z0idberg ( 888892 ) on Friday January 13, 2006 @08:56AM (#14462531)
    If you take a look at the patent holding companies website (Solomon Technologies inc. ) it looks like they developed the technology and have been implementing it (in sailing vessels) for some time.

    From their FAQ:

    What is the Electric Wheel(TM)?
    The Electric Wheel(TM) is a new technology motor (first patented in 1991) that significantly improves and exceeds the net horsepower output of existing electric and fossil fuel motors. Solomon Technologies currently provides three series of motor systems built on this technology; the ST37, the ST58 and the ST74. They have been designed for use in marine environments. The ST58 combines variable torque converters, brushless motors with Neodymium Iron Boron (NeFe B) magnets, and a powerful regenerative feedback function that converts the motor(s) into a generator of electricity to recharge the batteries while under sail, and provide electrical power to other appliances on the boat.

    So looks like they are legit (or are a very elaborate front :-) )
  • by tdemark ( 512406 ) on Friday January 13, 2006 @08:59AM (#14462543) Homepage
    I respect the rights of patent owners, and I'm not sure how you could legally sanction this berhaviour without harming patent holders' legitimate rights, but the practice is just plain sleazy.

    If a product that uses your patent without an agreement in place is on the market for X months and you, the patent holder, do not challenge such use, a license is automatically granted for that product.

    If you have reason to believe a product is using your patent, you can file a challenge with the patent office stating so. The company offering the product has to respond saying that they are or are not violating your patent. If they say they are not, the previous "X month" window gets extended to the full term of the patent for that product. If they aren't using your patent, this has no effect. If they are using your patent, and tell the patent office they aren't, you now have the full term of the patent to prove them wrong.

    You can only exercise this challenge Y times over the life of the patent. Y will not include any challenge that is upheld, either initially or after the fact.
  • by Dr_LHA ( 30754 ) on Friday January 13, 2006 @09:02AM (#14462555) Homepage
    The "and possibly other hybrid companies" is just pure speculation.

    Indeed, hence the correct usage of the word "probably".

  • Don't laugh! (Score:5, Informative)

    by aquarian ( 134728 ) on Friday January 13, 2006 @09:24AM (#14462641)
    Cobasys, a Texaco subsidiary, holds a patent for NiMH batteries. One of the reasons for the hybrid itself is that it carefully skirts this patent by having the internal combustion engine as the prime mover. A battery-only or battery-mostly vehicle might be subject to prohibitive license fees. This is why pluggable hybrids have not been commercially produced either.

    Oil company conspiracy? You decide...
  • by Phreakiture ( 547094 ) on Friday January 13, 2006 @09:27AM (#14462652) Homepage

    [Their] patent is pretty complete, but only filed in 1990.

    Unfortunately, I think reclaiming [braking] energy with an electric motor was thought of, and used much earlier [than] that.

    I seem to recall an article that was published in the late 1980s in Popular Science profiling a prototype hybrid car that was called the Uniq. It had regenerative braking.

    Rail locomotives have had "Dynamic braking" for decades, in which energy is reclaimed from the wheels, but it is subsequently burned off in a huge resistor, but it is at least half of the formula.

    So that takes regenerative braking itself off the table as far as prior art. That leaves the combiner gearbox.

    The Uniq used no combiner gearbox, and neither do Honda's hybrids. Toyota has done a better job at marketing their hybrid drive, but Hondas are actually getting better MPG without the combiner gearbox (though a pure electric mode is not possible).

    The bottom line is: There is some prior art; it is probably not enough to help Toyota with their immediate problem, but not all hybrids are affected.

  • Re:good patent? (Score:4, Informative)

    by Epeeist ( 2682 ) on Friday January 13, 2006 @09:30AM (#14462669) Homepage
    > That being said: where do you think R&D money comes from?

    > Once example: You do realize that developing new medicines costs a crapload of money right?
    > You do realize that companies who develop medicines depend on patents to guarantee that it
    > cannot be copied so they can make more money and make more medicines right? Thankfully, the
    > patents expire and the drugs become generics, bringing costs down.

    Pharmaceutical companies do spend a fair amount on R & D. However, it is nowhere near as much as they spend on marketing. The reality is that they are using patents to control the market, not to recoup their R & D investment.
  • Re:Blah (Score:2, Informative)

    by minkie ( 814488 ) on Friday January 13, 2006 @09:36AM (#14462709)
    The physics of aerodynamics pretty much drives the exterior shape of the car if you want to get good highway mileage.
  • by thebdj ( 768618 ) on Friday January 13, 2006 @09:43AM (#14462745) Journal
    EPO and for that matter every country (or at least the vast majority) use a first to file system. So an inventor often gets punished because big company X can file before they can since they have the money to start what is a very costly procedure. In the US Patent System, it is a first to invent. If two entities have filed for the same patent an interference procedure is followed where the Board of Patent Appeals and Interferences (BPAI) will hold a hearing and make a determination based on the facts presented by both who was the first to actually invent the application.

    Under the US Patent System, it counts as prior art if it was published by "others" (this means any person or group of persons different from the applicant) before the invention of the device. This is called 102(a) and they can swear behind this using the whole first to invent idea. Initially, items are considered "invented" when tey are filed. It also counts if a publication is made or it is in "use" (in the terms of in the public already) by anyone (including applicants) more then 1 year prior to the earliest US filing date. This is a 102(b) and a so-called "statutory bar". There is no way to swear behind these kinds of references. The final one that is commonly used is if a published US application or Patent was filed before the filing date of the current invention by another (this also applies to WIPO filing dates). This is called a 102(e) and like 102(a) is based on invention date so it can also be sworn behind.

    I think you need to clarify the prototype being officially made statement. I cannot speak certainly for EPO or other patent offices, but the general idea is that the item described in the Patent Application has actually been invented. As such, there had better be a prototype of some sort sitting around somewhere. Most all patent laws center around a publication or existance of an item that is known to the public in same.
  • by thebdj ( 768618 ) on Friday January 13, 2006 @09:48AM (#14462765) Journal
    20 years from the filing date of the application. I do not think it is as low as 5 anywhere in the world. This is of course only for Utility Patents. I think Design Patents are 14 years and I have no clue about Plant Patents.
  • Re:Due Diligence (Score:1, Informative)

    by Anonymous Coward on Friday January 13, 2006 @09:51AM (#14462786)
    Don't listen to the AC, but I think that's trademark law, not patent law.
  • by PianoComp81 ( 589011 ) on Friday January 13, 2006 @09:57AM (#14462837)
    As a UK citizen, I'm unfamiliar with US law - how long does a US patent last? I assumed it was 5 years, considering this patent was filed in 1991 (if I read correctly) it must be at least 15 years monopoly - something that seams completely unfair to the progression of business...
    Take a look at _United_States []. In general, it's 20 years (17 for patents before 1995, as this one was)

    The main reason for making it so long is that people and companies typically file the patent while R&D is still going on. It can take 5-10 years (or more) after the patent is filed for the product to come to market. This is especially true with drugs in the United States, as the process with the FDA takes an extremely long time.
  • Re:Diagram (Score:1, Informative)

    by Anonymous Coward on Friday January 13, 2006 @09:59AM (#14462853)
    So if you want a visual of what they're actually talking about, look here because that damned patent site refers to images that are nowhere to be found.

    Perhaps the images are collected under the LARGE RED OUTLINE BUTTON LABELED "IMAGES" at the top of the linked page.


    A patent attorney.
  • by kansas1051 ( 720008 ) on Friday January 13, 2006 @10:17AM (#14462991)
    The term of a US patent is 20 years from filing or 17 years from issuance, depending on when the patent was filed. The patent referenced in the article is subject to the "greater" of 20 years from filing or 17 years from issuance, so its valid at least until 2009. These patent terms are generally consistent with all other countries (developed and undeveloped), no nation has a 5 year patent term (England's term was traditionally 14 years from issue, I don't know what it is now).
  • Re:Diagram (Score:3, Informative)

    by mzwaterski ( 802371 ) on Friday January 13, 2006 @10:28AM (#14463081)
    As the anonymous coward stated, there is a big red button for images. However, chances are your problem is that you need a good TIFF viewer that works with the USPTO setup. See Innomage Internetiff. They have a free version. Otherwise visit any one of the many sites that provide free PDFs of patents.
  • by joepeg ( 87984 ) on Friday January 13, 2006 @10:29AM (#14463086)
    Patents require very specific designs. If my hybrid car uses batteries, and yours uses hamsters running in a wheel, they are not the same thing.

    If say I invented X and didn't know that you too had invented X, would I then be in infringement?

    If they are the same design, they patent theirs, and you try to sell yours, then yes, you are in infringement.

    I come to think about the Clean Room Design method where one apparently is allowed to reverse engineer any copyrighted product as long as you recreate a design spec solely based on "observation".

    Can the same be done for patents issues? Say you had invented X, could I then "observe" and "reinvent" X?

    Yes, as long as you really just observed it, and don't end up with the same exact design by chance.

    While researching Genetic Algorithms, I came across a story about someone who had built a GA that designed circuit boards. When he executed it, telling the machine to design a board for a particular use, the GA designed many resulting boards, 4 of which infringed on existing patents.
  • Re:/tin hat (Score:4, Informative)

    by The Spoonman ( 634311 ) on Friday January 13, 2006 @10:35AM (#14463125) Homepage
    Notice all the Nutrasweet bashing going on among health gurus over the last couple of years. It was the perfect sweetener, now it causes everything from headaches to severe thunderstorms.

    That bashing's been going on since soon after the product hit the market []. I think the patent expiring is why you're hearing more about it because there isn't anyone to "stifle" the truth anymore. The [] headaches []are actually caused by brain lesions []. But, those aren't the worst part, the blindness []is what really gets you. (For the tin hatters out there [])
  • by slashbob22 ( 918040 ) on Friday January 13, 2006 @10:44AM (#14463192)
    You are correct, provided you are willing to risk an explosion [] See the "Warning" section. Lithium batteries are not used in automotive applications due to their volitile nature. I believe some new technologies are upcoming to mitigate these risks.
  • Re:Easy Solution. (Score:3, Informative)

    by Transcendent ( 204992 ) on Friday January 13, 2006 @11:05AM (#14463360)
    Unfortunately the breaking system is a major part of the efficiency boost. Whenever you break, power is generated and stored into the batteries. Accelerating obviously uses up this power again.

    Without the breaking system advantage, your hybrid car won't get any significant fuel efficiency boost.
  • Re:Don't laugh! (Score:3, Informative)

    by bracher ( 33965 ) on Friday January 13, 2006 @11:21AM (#14463518)
    Cobasys [] is a joint venture [] between Chevron (not Texaco) and ECD Ovonics [].

    I first heard about ECD in this transcript [] of a Scientific American Frontiers episode. Two segments on them, one talks about storing hydrogen as a solid (in alloy hydrides) and the second talks about their solar panel tech. Sort of ironic to see them pop up in this thread...

  • Patent Length (Score:3, Informative)

    by Ironsides ( 739422 ) on Friday January 13, 2006 @11:31AM (#14463612) Homepage Journal atdesc.htm []

    Although, the length of utility and plant patent protection (patent term) was previously seventeen years from the date of patent grant, utility and plant patents filed after June 8, 1995 now have a patent term of up to twenty years from the date of filing of the earliest related patent application. Utility and plant patents which were applied for prior to June 8, 1995, and which were or will be in force after June 8, 1995, now have a patent term of seventeen years from the date of patent grant or twenty years from the date of filing of the earliest related patent application, whichever is longer. Utility patents are subject to the payment of periodic maintenance fees to keep the patent in force. Patent terms can be extended under some specific circumstances. See the U.S. Code Title 35 - Patents for a full description of patent laws.
  • Re:Don't laugh! (Score:3, Informative)

    by kfg ( 145172 ) on Friday January 13, 2006 @11:36AM (#14463670)
    That's ok, so has the hybrid itself. Dr. Ferdinand Porsche's first design, circa 1900, was a hybrid that was even perspicacious enough to use hub mounted motors. With hub mounted motors you have to do little more than reverse the polarity when the brakes are applied to acheive regenerative braking.

  • Re:Don't laugh! (Score:3, Informative)

    by leoc ( 4746 ) on Friday January 13, 2006 @11:38AM (#14463690) Homepage
    This myth has been addressed extensively by the electric car community:

    The Efficiency Advantage of EVs and Power Plants
            EVs recharging from fossil-fueled power plants such as coal and oil have unique
    efficiency advantages over ICE vehicles. As a system, EVs and power plants are twice as
    efficient as ICE vehicles and the system that refines gasoline. See Table 4. Although there
    are losses associated with generating electricity from fossil-based fuels, EVs are
    significantly more efficient in converting their energy into mechanical power.

    [ table showing 28% for EV's, 14 for ICE]

            Since EVs operate more efficiently then their ICE-powered counterparts, overall fuel
    economy is higher. However, making a direct comparison between the fuel efficiencies of
    both vehicles is difficult. By applying a common unit of energy, such as British Thermal
    Units (Btus) we can get a fair comparison between the two.

    Read the rest. It is VERY eye opening. []

  • Re:/tin hat (Score:3, Informative)

    by Dun Malg ( 230075 ) on Friday January 13, 2006 @11:55AM (#14463868) Homepage
    I don't know why you got modded funny. It should be a well know fact (especially to /.ers) that OPEC buys up every alternative energy/locomotion patent it can get its hands on, and then calls it "Research".

    And I don't know what nut(s) modded you "insightful". The only "evidence" supporting such a crazy claim is a bunch of urban legends. Name one technology that OPEC "bought up" and kept secret. Ah, that's right. It's being kept secret! Complete absence of evidence is the sureset sign the conspiracy is working, right? Does it not seem odd that in fifty years of this (or similar) story floating around that not once has there been a leak, or a parallel discovery by a non-bought off inventor? Gimme a break.

  • Don't panic (Score:4, Informative)

    by originalhack ( 142366 ) on Friday January 13, 2006 @12:02PM (#14463933)
    I had a professor in 1985 at the Univerity of Illinois who had built and published papers on an electric vehicle with regenerative braking. There is a nice report somewhere from the fire department on that one (NiCd-fire). At that point, the concept of gas-turbine/battery hybrids were already well under discussion.

    There have certainly been some interesting innovations that make modern hybrids possible since then, primarily the interesting motor/generator/transmission gadgets, but the fundamentals that are critical to all hybrids go back way further.

  • Re:/tin hat (Score:1, Informative)

    by KowShak ( 470768 ) on Friday January 13, 2006 @12:06PM (#14463965)
    I'm afraid you can't do that, not once you're selling it or somebody else is.

    Once you start selling something you can't retrospectively patent it.
  • Re:Easy Solution. (Score:3, Informative)

    by kfg ( 145172 ) on Friday January 13, 2006 @12:08PM (#14463988)
    If I may take the liberty of quoting from an electric car builder with 30 years of experience and founder of the Electric Car Club:

    . . ."while braking the car, you can slow it down by converting the forward motion of the car into electricity that can be redirected to the batteries. This is known as regenerative braking. From my perspective, the added weight and complexity of the regenerative braking system, plus the low absorption efficiency rate of conventional batteries, ultimately provides for little if any gain in range for the vehicle. In the case of long range driving, with little braking required, the added weight of the regenerative braking system, probably reduces range somewhat."

    Yes, regenerative braking can add to the efficiency of hybrids under certain conditions they are not a primary reason for the efficiency of the system and may under other circumstances actually degrade it, even with the advances made since the above was written.

    A properly designed hybrid gains its efficiency through reducing the weight and friction of the conventional drivetrain and by operating the fuel engine at a constant rate tuned for maximum efficiency.

    The current line of commercially available hybrid cars are not properly designed, their designs being determined by various legal, political, social and marketing reasons, not engineering.

    They actually gain what little added efficiency they possess through reducing weight and aerodynamic drag in ways that are perfectly applicable to a fuel powered vehicle. They are compelled to marketing these cars as gaining added efficiency through regenerative braking because that is the one feature they can point to that is unique to their vehicles, not because it actually works as well as it is promoted.

    Give me a Prius shell and I can turn it into a conventional fuel powered car with equal or greater fuel economy without giving up, and perhaps gaining, performance.

    If past experience in putting forth this inforamation is any guide, I am about to recieve any number of retorts telling me I have to be an idiot to believe that regenerative braking does not add to the efficiency of a vehicle, because the point seems obvious.

    But the point is not obvious, which you would know if you had ever actually designed and built one of these things as I have.

    Regenerative braking can add to the efficiency of a particular vehicle under certain circumstances, but says nothing about whether another vehicle can be designed and built with greater efficiency without using regenerative braking.

    And I'm sorry, but cars like the Prius are relatively crude designs whose efficiency could be increased by converting them to conventional diesels (or even gas) without the benefit of regenerative braking, especially in highway cruising mode where hauling the system around is just a leech on the fuel economy.

    And that's just the way it is.

    A proper hybrid never runs on anything but electric power, using the fuel engine solely to turn a generator which drives the electric motors directly and the batteries function as a reserve energy sink, not the prime energy source.

    And even in this kind of hybrid regenerative braking can result in a net loss of fuel economy if you are primarily driving it at constant speed on the highway, because you don't do much braking in the first place.


  • Re:/tin hat (Score:4, Informative)

    by 2short ( 466733 ) on Friday January 13, 2006 @12:40PM (#14464333)
    That doesn't work. Once an invention is out there (on sale or otherwise "published"), you have a limited time (a year IIRC) to file for a patent.

    The standard Pharmaceutical company trick is shortly before the patent expires, they introduce a new version with a trivial (but newly patented) "improvement". Aggressive marketing tries to get all their current customers switched to the new drug. When the patent expires, other companies can make generic versions of the original drug, and these may for all practical purposes be just as good at treating whatever it is, but pharmacists can't make the substitution for the new one without a new prescription.

    The other trick is to find new uses for current drugs, and patent those new uses, which gets weird in that eventually generic companies can make the exact same drug, but not market it for the new purpose.

    Both of these seem to me like side effects of applying patent law, which works reasonably well for things like mechanical engineering, to other realms.
  • by dtjohnson ( 102237 ) on Friday January 13, 2006 @01:19PM (#14464691)
    The Figure 1A in the patent looks more like a Chrysler K car than a Prius. Also, the transmission in Figure 2 looks more like the transmission on a McCormick Farmall tractor with the option power take off. Maybe the inventor was influenced by previous art or one of those Iacocca TV commercials from the '80s.
  • Re:Easy Solution. (Score:5, Informative)

    by kfg ( 145172 ) on Friday January 13, 2006 @01:39PM (#14464885)
    The Prius does not reduce emmisions. It reduces emmisions at the tailpipe compared to a conventional system.

    When you consider the emmisions cost of the entire system, production, energy production/transmission and disposal, the current commercially available hybrids are unmitigated environmental disasters hidden by ignorance, smoke and mirrors.

    How to get 10 mpg better milage while reducing emmisions from a standard, gasoline burning Accord:

    Regear and retune the engine to give maximum efficiency while producing the same level of performance as a Prius.

    Notice in the above post that the driver achieved his milage in the Prius through modification of his driving technique.

    As a demonstration I once achieved 40 mpg from an completely box stock, 1976 Ford Fiesta on the open road simply by driving with my mind on efficiency rather than performance. If I had modified the car to run in this manner innately it would have reduced its emmisions greatly as well.

    The Prius owner quoted above is an efficiency minded fellow who drove his car with his mind on driving as efficiently as possible. It is a biased anecdote.

    Gas powered CRX drivers reported getting 60 mpg with low overall emmisions. The cars were simply tuned for economy rather than performance as well as being smaller and lighter than a Prius. It did not sell well, because it lacked performance. Buyers of this car, and the buyers of the Prius, are innately people who are willing to sacrifice performance for efficiency and the purported benefits of the hybrid system come mostly from this sacrifice of performance, not from the hybrid system.

    Give me a blank sheet of paper and I will design you a vehicle that can sustain 30 mph on only 60 watts of power, is fueled by pizza and exhausts relatively small amounts of CO2 balanced by the carbon cycle.

    But you would not likely buy such a vehicle because it would not make you happy.

    The current line of hybrids are designed to make people happy by giving them the impression that they are achieving reduced fuel use and emmissions over some other system.

    As an engineer I love electrics and hybrids and have been involved with them since the mid 70s. They are elegant. I appreciate that elegance.

    But the claims surrounding the current crop of hybrids are faith based, not engineering based.

    And people will defend their faith no matter.

  • by sandmaninator ( 884661 ) on Friday January 13, 2006 @01:54PM (#14465062)
    I've been lusting for Solomon technologies electric wheel for my boat for years. The first thing that popped into my mind when I saw the Hybrid cars hit the market was "This should speed up the adoption of this tech in boats and make it affordable".
    If it turns out Toyota lifted Solomon's tech, Solomon deserves to be compensated. The market will find a way for this tech to continue to exist.

    But, from a user point of view, the thing that really needs to happen is for batteries to get better and cheaper.
  • Re:Easy Solution. (Score:4, Informative)

    by kfg ( 145172 ) on Friday January 13, 2006 @02:58PM (#14465665)
    All the marketing hype and perceived value to a Prius has always been centered on city traffic.

    Where cars themselves are especially stupid, and if you look at the packaging of a Prius it is obviously not a city commuter model but is equiped as a long range family hauler, because that is what people expect and will put their money down for.

    . . .my average 10 minute drive

    You are efficiency and environmentally concious and you drive ten minutes to work, including two to three minutes stopped at lights and a train crossing?

    I would be ashamed of such an admission and all of your Prius, used as such, represents nothing but fuel waste in the first place.

    the Prius gasoline engine TURNS OFF. So typically, I spend 2 to 3 minutes of my average 10 minute drive not poluting at all.

    Are you aware of the fuel and emmissions costs of simply turning on a gasoline engine? They can exceed those of an engine idling for a minute or two. You would gain more benefit from this is you commuted on the Long Island Expressway, not in your short commute.

    Also, a very simple engineering fact is that the amount of polution released in the atmosphere is directly related to the amount of fuel that is combusted.

    No, this is intuitively obvious, but it is a simple engineering fact, that is to say empirical, that it is not always true, because a gasoline burning engine does not operate with a flat burning efficiency curve.

    . . .is combusing less fuel because some of the energy contributing to the work is coming from a battery.

    Which energy was produced by the elves that live under my bed?

    Thus the Prius will be expelling less waste (pollution) than the other vehicle.

    From its tailpipe. This is not at all the same thing as saying that its use expells less pollution. You have fallen prey to the smoke and mirrors. You are expelling that added pollution into my backyard instead of yours. I don't necessarily appreciate your treating me in such a fashion.

    Even if that difference is less than 1%, it's still better than nothing.

    Have you ever driven a conventional gas engineed car designed and tuned to your particular commute and measured it's fuel efficiency and emmissions against the Prius?

    You are, I'm afraid, one of these people who see certain gross functions of the vehicle and translate that into a feeling that you are coming out ahead, without actually knowing that you are.

    Your use is faith based.

    You can crunch all the numbers you want on emmisions and functioning of the Prius system. . .



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