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What to expect from the next model year Prius



  • PF_FlyerPF_Flyer Pennsylvania Furnace, PAPosts: 7,770
    The purpose of this discussion is supposed to be talking about waiting for the 2009 Prius, not the safety merits of hybrids.

    I'm going to remove the recent off topic stuff in an attempt to get us back on track.

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  • fordenvyfordenvy Posts: 72
    You really put a stop to this forum, that was good stuff I was reading.
  • PF_FlyerPF_Flyer Pennsylvania Furnace, PAPosts: 7,770
    If you'd like to discuss safety issues,trythe Prius Safety & Crash Test Ratings discussion.

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  • larsblarsb Posts: 8,204
    This is a NICE looking car....

    Spy 2009 Prius

  • gagricegagrice San DiegoPosts: 31,112
    Better styling than the last one. Still too many blind spots for me to consider one.
  • morey000morey000 Posts: 384
    Hope they don't replace those nice mag wheels,
    with the hubcaps that are on the current model.
  • 210delray210delray Posts: 4,722
    Believe it or not, but the current Prius has alloy wheels standard, but there are plastic outer rims to protect the wheels from curb rash.
  • Friends:

    This does not seem to make sense. New cars are going for $21-25k, while used ones from 2004 with comparable options are being listed in autotraders within $17-22k range.

    This makes the 3-yr residual for cars bought in 2004 at over 80%. That seems believable for a Toyota (or a Honda for that matter). But why is the residual value on new Prius's as low as 52-54% (as reported by other posters)?

    Does it mean that the resale values of today's cars, after three years (2010-2011), would be substantially lower, when the new generation of hyrids (80-100 mpg) hits the market?

    If this is true, then, for those who can afford to defer their decision by a year or so, does it make sense to wait?

    Please advise. My lease ends in a month ... I love the car, despite its heavy fuel consumption, which forces me to actively consider a hybrid ... but I'm concerned about how much value I might lose in 3-4 years. Is there anyone with access to a crystal ball???

    Thanks in advance,
  • kdhspyderkdhspyder Posts: 7,160
    Don't confuse residual value with retail resale value or trade-in value for that matter.

    The fact is that residual values on leased vehicled always will show about a 50% loss after 3 or 4 yrs no matter what vehicle you are discussing. The auto finance company is protecting itself because it is required to 'buy back' your vehicle at the guaranteed residual value.

    Trade in value is usually lower still because the trading company has to consider that it has to add costs to bring the traded vehicle back to market and it has to pay a commission to the sales person and it has to make a profit on the resale.

    Retail resale value depends on a huge array of factors which might distort the figures dramatically. If your local community has a relative 'shortage' of used hybrids then the ones trying to sell theirs in the paper and online will certainly be looking to get top dollar. You also have to make sure you are comparing apples to apples in equipment. There is a significant different in price between a base Prius and a loaded '04 model. It might be $4000-$6000.

    Finally supply is the key factor in resale pricing. Toyota just jumped the supply of Prius' by nearly 60% this year as opposed to 2004 when they had a true shortage situation.
    ~ 70000 sold in 2004
    ~150000 will be sold this year.
  • wwestwwest Posts: 10,706
    Article in the NYTimes seems to indicate the next Prius will be rear engine RWD....
  • kdhspyderkdhspyder Posts: 7,160
    I can only imagine that it will be one of the 'Prius' models that were discussed last year. At that time there was talk about an A, B and C model coming as Toyota might go with a whole 'Prius' mini-lineup like the Scions.
  • bennbbennb Posts: 143
    From what I've heard the '09 will be a mild re-fresh (different headlight style and the like) ... the major change will be in 2010. Also heard '09 may have lithium ion batteries that will get better fuel economy, but that may wait till 2010 as well.
  • 210delray210delray Posts: 4,722
    That's correct about the '09 -- just a refresh. I believe the next generation car has been delayed to calendar year 2010, so when it appears, it will be a 2011 model. The lithium-ion batteries won't show up until the new generation debuts.
  • stevegoldstevegold Posts: 185
    What about the turbo and the auto parallel parking feature?
  • 210delray210delray Posts: 4,722
    No turbo for this generation; I don't know about the parallel parking feature.
  • wwestwwest Posts: 10,706
    I don't believe that an Atkinson Cycle engine would have enough energy/heat left in the exhaust output to drive a turbo. Barely enough to keep the catalyst at optimum temperature as it is.

    On the other hand a small lightweight (carbon fiber??)variable speed positive displacement SuperCharger (w/intercooler) driven by an AC motor, itself driven by yet another variable frequency AC solid state inverter, might be an ideal solution.

    Or maybe an SC primarily belt driven by the engine but via another e-CVT controlled by a light duty/hp (5-7HP??) AC motor on the opposite end of the planetary reduction gearset. 4:1 reduction would yeild 25-28 HP to the SC and allow continously variable BOOST through the Full RPM/load range of the ICE.

    Minimal or no BOOST at all just cruising along and no high RPM OVER-boost to provide a WASTE bypass for.
  • stevedebistevedebi LAPosts: 4,098
    "I don't believe that an Atkinson Cycle engine would have enough energy/heat left in the exhaust output to drive a turbo. "

    Turbos are driven by exhaust pressure, not temperature.

    Keep in mind that a supercharger is mechanically driven and requires energy to run - it boosts power at the cost of economy. To make the net use of SC workable, the engine would have to be smaller or use less fuel.
  • wwestwwest Posts: 10,706
    "Turbos are driven by exhaust pressure, not temperature."

    And just what do you think causes all that exhaust (gas) pressure, if not the HEAT of combustion? The Atkinson Cycle allows more EXPANSION, less pressure into the exhaust manifold, of the ignited A/F mixture during the power stroke relative to normal "Otto" engines.

    "It boosts power at the cost of economy."

    SURE DOES...!!

    And that's exactly the point...!!

    Anytime, ANYTIME, you put that "pedal to the metal" you are asking for POWER in leu of FE.

    The idea of an SC or TC is to make a small engine act like a BIGGER one when the driver calls for POWER.

    The Atkinson Cycle makes efficient use of the WASTE energy that might otherwise be used to drive a Turbocharger.

    An SC configuration as I have suggested would not be a parasitic load on the ICE unless an extraordinary level of POWER was asked for.
  • stevegoldstevegold Posts: 185
    I almost bought and installed a high power electric (DC)
    turbo which would have fit right in the air intake tube on my 2004. It would have given a good pressure boost but was designed for only 30 second operating cycles. The seller (ETurbo) said it would burn up if used for more than a minute at a time. I only needed it on long, straight, steep interstate mountain passes like just west of Denver. Those take 5-10 minutes to climb. Everything else works fine (short, curvy, not too steep).
  • stevedebistevedebi LAPosts: 4,098
    "And just what do you think causes all that exhaust (gas) pressure, if not the HEAT of combustion? The Atkinson Cycle allows more EXPANSION, less pressure into the exhaust manifold, of the ignited A/F mixture during the power stroke relative to normal "Otto" engines."

    Your original statement was about there being insufficient heat from an Atkinson cycle to run a turbo. I gather from your response that you meant that there was insufficient pressure to run the turbo.

    I can't quite tell if you agree with me vis-a-vis superchargers, but the point is that if you put in a smaller engine to maintain the MPG you don't gain a lot of power. Plus it adds weight and complexity to the engine.

    Note also that you can't "turn on" the power of a SC when desired; it is always on, boosting power and reducing MPG.

    Toyota isn't interested in maxing out the performance of the Prius; it is strictly designed for maximizing fuel economy.
  • stevegoldstevegold Posts: 185
    It depends. An "electric turbo" is only on when the pedal is floored. In my case, I only need the boost 5% of the time.
    A slightly smaller, more efficient engine would be fine 95% of the time and on the rare occasions when I do need the boost, it would be there. I think my normal 45-48mpg would go up to over 50mpg except for 5% of the time when the "turbo" was on.
  • wwestwwest Posts: 10,706
    In the exhaust manifold of a car HEAT IS Pressure...

    If you could make the combustion process fully efficient the exhaust gasses would exit the cyclinder at the exact same temperature at which they initially entered the cyclinder.

    The Atkinson Cycle gets more efficiency from the fuel BURN by extracting more of the HEAT and converting it to mechanical motion. Less HEAT/(pressure) at BDC equals less pressure into the exhaust manifold once the exhaust valve opens.

    The SC technique I described allows for continuously variable boost pressure from zero to the maximum allowed by the mechanical limits of the engine and thereby NO LOAD on the ICE until boost is required/called for.
  • stevedebistevedebi LAPosts: 4,098
    "It depends. An "electric turbo" is only on when the pedal is floored. In my case, I only need the boost 5% of the time. "

    I was speaking of supercharging, not Turbocharging.
  • stevedebistevedebi LAPosts: 4,098
    "In the exhaust manifold of a car HEAT IS Pressure..."

    Don't try and put that statement to an automotive engineer, or a physics professor.

    I don't understand what kind of "technique" you are describing. Superchargers use the engine power to mechanically enhance the airflow into the engine - the same principle as the turbo charger, except the turbo is driven by exhaust gas, and therefore increases as the engine RPM increases, whereas a supercharger provides constant power - but the energy to power the supercharger has to come from somewhere, and the equipment adds weight to the engine.
  • stevegoldstevegold Posts: 185

    This is the electric turbo that I thought would work well in the 2004 Prius. It runs at high speed off the 12VDC battery but only when you floor the accelerator.
  • pathstar1pathstar1 Posts: 1,015
    An Atkinson cycle engine with a supercharger is a Miller cycle engine. AKA Mazda 626. If you do a search on Atkinson cycle, the Miller cycle is also mentioned. It will not run without the supercharger. I have some experience with that, when the supercharger "ate" a hose clamp. :) I smile because it wasn't mine. I didn't get the privilege of paying $4000 to repair it. And "they" dis the Prius because "they" think the battery would be expensive to replace!

    While some may feel more HP is necessary, many of us think the Prius does just fine, thank you. Mine will out accelerate my previous vehicle on the two lane secondary highways when passing 18 wheelers (it was a 240 HP 265 lb-ft torque 2001 Nissan Pathfinder, which, BTW, burned 2.5 times as much fuel for the same service). It will not keep up from a stop, mainly due to the "delay" of 1/2 to 1 sec. at startup.

    At any rate, this discussion is of the 2009 model, which, from all accounts, will not have a supercharger or turbocharger. In fact, it now appears it will be the last year of the current version car. Most now conclude the 2010 model will be the "changeup" year. Probably will have the same engine, a double sized battery, with plug in capability, and a cruising range on battery only of around 10 km. But this is all speculation, based on comments from Toyota spokespeople and their tests with the double battery pack Prius plug in test vehicle in Japan and California. They have also given some hints as to body design changes. Just have a look at the "bean shaped" (my description, not intended as criticism) concept car shown last winter in Germany. "Many things you will see on future hybrid cars from Toyota are on this concept car." Note he said "many", not all.

    Several posts ago, someone said a gearbox will raise the HP output. Sorry, a gearbox will change the torque and the RPM, but the HP stays the same (actually it drops a bit, due to losses in the gearbox). Energy MUST be conserved!
  • stevedebistevedebi LAPosts: 4,098
    "An Atkinson cycle engine with a supercharger is a Miller cycle engine. AKA Mazda 626. If you do a search on Atkinson cycle, the Miller cycle is also mentioned."

    Don't look at me, I didn't suggest it; I was responding to a different post...
  • wwestwwest Posts: 10,706
    The Prius implementation of the Atkinson Cycle is more logical/virtual than real, but...

    The Prius is using delayed intake valve closing so that a portion of the A/F mixture is forced back out into the intake manifold (and into the "opposite" cylinder currently on an intake stroke) during the compression stroke. The result is effectively, logically, the same as with an actual Atkinson Cycle engine, a "lengthening" of the power stroke in comparison to the intake stroke.

    But in order to keep some of the "power" normally lost to the Atkinson Cycle the Prius' mechanical compression ratio is raised to 13:1 leaving an effective ratio still at 10:1.

    Basically that means using an SC would raise the "effective" CR above 10:1 which the engine may not be able to stand up to in the long term, even in short bursts of 30 seconds.

    Additionally I would be willing to bet that the e-charger's 1 PSI boost is only at low to mid engine RPM and actually goes negative, starving the engine, as it reaches the RPM in what would normally be PEAK HP.

    A toy, at best.
  • toyolla2toyolla2 Posts: 158
    Although Julian Edgar of Autospeed did find improvement with a turbocharger, his was an anaemic pre-Gen 1 model that was shipped from the Japanese market to Australia and not available in North America. The Gen I and Gen II that arrived on our shores in comparison are fully able to drive their MG1s to their full rating of 100 Amps. Increasing the power of their engines with some sort of forced induction scheme will not improve their performance. Here's why.
    First it should be noted that the magnetic field of MG1, which indirectly controls engine torque, is produced by neodymium magnets which are not adjustable. The effect of this field is that MG1 requires a torque value of 22lbs-ft from the sun gear when generating 100 amps of current. Since this generated current is electronically regulated not to exceed 100 Amps this simultaneously places a useable torque limitation on the engine. In other words it doesn't matter how much more torque capability you endow this engine with, it just cannot be allowed to push MG1 into generating more than 100 Amps or it will overload that machine. The intractable situation is that the more powerful you can make the engine, the more severe the throttling back by the Prius control system will be.

    Next regarding the gearbox ratio change, I'm assuming we're referring to the 4.113 transaxle ratio, which offers some possibilities. The Prius system develops its maximum contant power output of 104Hp from 51mph to 100mph so the gear ratio is ineffectual in this area as someone pointed out. On the other hand the point at which the constant power is reached can be lowered by using a higher ratio and that would have the effect of reducing the 0 to 50mph acceleration timing and improving hill climbing ability.

    Changing 4.113 to 5.00 will lower the entrance to the max constant power point to just 40mph. The result being the that the previously 68.6Hp being developed by the engine at this speed will be upped to the 76Hp maximum. A 10.8 % increase ? No, not quite, because the battery is supplying 28Hp so the actual System increase is only (104-68.6-28)/(68.6+28) X 100 = 7.7% . This is a surprising result since most of us would expect a 20% improvement in torque going from basically 4:1 to 5:1 in the final ratio. So at 40 mph only a 7.7% improvement is realized. The problem here is that you're fighting two constant power systems. MG2 constant power from 20mph to 50mph and then the engine itself from 51mph speeds and up.
    The 20% improvement should be present in the 0 to 20mph range, not that you would much notice, but then it becomes minimal in the all important 20 to 50mph range.

    I am going to leave this discussion by simply noting that it appears that in these connected constant power systems you cannot just improve one component i.e. the engine by itself. You will need to upgrade the MG1s and MG2s as well. The transaxle ratio (4.113) or the HSD planetary ratio (2.6) are merely the glue that holds the system together. I am sure that alteration to the HSD ratio to accommodate greater engine torque will lead to further circular reasoning that will oblige upgrades on the other electrical equipment to be necessary as well.

    As a side issue, the genius of the HSD becomes particularly apparent here. As MG2 fades above 51mph (the volts/herz issue) makeup power comes automatically from the direct mechanical link at 6.6Hp per 10mph. At 100mph 66Hp comes directly from the engine, while the now less capable MG2 will only be required to handle 38Hp (10Hp+28Hp). This would correlate well with electric motor theory were MG2 an induction motor, but with a brushless motor it's difficult to predict exactly how much power MG2 could deliver beyond the mandatory 10Hp as top speed is approached. Any takers ?
This discussion has been closed.