How can they improve the fuel economy of the next generation Pruis?

Discussion in 'Gen 3 Prius Technical Discussion' started by techman41973, Aug 28, 2012.

  1. bwilson4web

    bwilson4web BMW i3 and Model 3

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    1. Clutch MG1 and ICE shafts - at speed, all power flows via the mechanical path, improving transmission efficiency ~4% at speed.
    2. Wheel well covers - reduce aerodynamic drag.
    3. Air dam and side skirts (inflatable?) - reduce aerodynamic drag.
    4. GPS managed SOC - approaching a frequent parking space, increase target SOC from 60% to 70% to provide charge for the next start.
    5. NVRAM memory - so the power off-state is more OFF. Only the smart-key receiver needs power and a small, photocell provides that power. Any other "OFF" power should come from photocells with enough to handle the dark.
    6. Eliminate the lead-acid battery - too much weight for too little power. However, allow 12V circuit to provide charge to traction battery.
    7. Auto tire inflating rims - so the tires remain at optimum pressure.
    8. Softer shocks and harder tires - lower rolling resistance while improving ride comfort.
    9. Radar/video, auto-cruise control, lane keep assist, and accident avoidance.
    10. Post catalytic converter energy harvesting - mechanisms to reduce the exhaust temperature and generate additional power. Include heat driven, cabin cooling system.
    11. Flex fuel - methanol, ethanol, as well as gasoline with tuning to exploit higher octane.
    Bob Wilson
     
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  2. ProximalSuns

    ProximalSuns Senior Member

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    Current low emissions Diesels in VW's, Merc's, Audi, Volvo's, etc. are all very reliable and as problem free as any gasoline engine.

    Hard to see how Prius hybrid will get to 60 mpg in 2015 without a Diesel given current battery technology. Diesel could do it.
     
  3. Munpot42

    Munpot42 Senior Member

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    I think there will be a great improvement in battery technology in the next two or three years, perhaps enough to make it a game changer.
     
  4. Blitzen

    Blitzen Junior Member

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    Plug-in Conversions Corportion (PICC) now claims to have a 12.5Kwh lithium-ion battery pack and software package that will boost any standard Prius to 7oMPH for 40 Miles in EV only mode! They say its 245 MPG for that range! (On par with the volt) The problem is this upgrade currently costs 15,000 thousand bucks because of the high battery cost so you'll never recoup your money but, according to government statistics, the price of batteries is supposed to drop to nearly a third of their current cost circa 2015. If the cost falls below 5,000 dollars I may be convinced to throw my company bonus at it so I can enjoy gas free work commutes.
     
  5. NiHaoMike

    NiHaoMike Member

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    They could put in wheel well covers, water injection, a larger engine that can run very lean on the highway, high energy ignition, and bigger batteries.
     
  6. WE0H

    WE0H Senior Member

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    I like the alcohol fuel idea. Have it setup so it can run E0 thru E100 to suit whatever an owner wants to run with no converter needed :)

    Mike
     
  7. austingreen

    austingreen Senior Member

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    Hey Mike,

    There are a couple of problems. The first is carb. Carb has regulations that hurt flex fuel vehicles, but they don't help the environment. Carb used to be pro flex fuel, but have changed the laws. They may get persuaded to change regulations back to favor flex fuel.

    http://www.netl.doe.gov/publications/proceedings/08/clean-cities-ca/pdfs/6.24Tues/Ehlmann%20%26%20Okabayashi%20-%20GM.pdf

    The key issues are E85 may increase NMOG during cold starts as well as evaporative emissions, but the prius wants SULEV ratings.
    This is slowing flex fuel in california and other CARB states, and since it is an important market for the prius the rules will stop the technology even if the fuel is cleaner after the engine warms.

    If that legislative problem goes away, then E0-E85 or M85 make a lot of sense. M85 makes sense in many states today as it is less expensive than ethanol and does not use food. The ice in the prius is likely more efficient with a high alcohol blend if the valves timing and mixture are set for it. M85 allows plentiful natural gas, as well as biogas and biomass to be converted to methanol fuel. Having the fleet able to burn E85 if celulistic ethanol technology progresses is a great hedge for the future.

    E100 is a problem further because of cold starts. M100 has this problem also, along with invisible flames. The brazilian cars that are e100 have a small tank of gasoline for cold weather starts, or warnings that they can not start in cold temperatures.
     
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  8. bwilson4web

    bwilson4web BMW i3 and Model 3

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    I wanted a higher SOC when parking to provide more energy when the car is parking. But it may be there is a simpler control law based upon speed. Our ZVW30 will let the SOC decay to much lower values when the car is running under the hybrid threshold speed, 46 mph. So I'm thinking:
    • warm engine, below 46 mph - slowly shift the target SOC up from 60% to 65%. This provides energy for the next cold-start.
    • warm engine, above 46 mph - slowly shift the target SOC down to 60%. Traction battery energy is less needed at higher speeds so having the head-room for regen makes sense.
    • cold catalytic converter - as now, the car maximizes traction battery use to keep the ICE at minimum fuel burn, idle. Currently, there is an increase in idle fuel consumption seen in the Scangauge II "gallons/hour" during the catalytic warm-up when in "D" versus "N".
    One other thought, perhaps a fuel-injector, resistance heater to improve vaporization while the intake manifold warms up. I'm not sure it makes sense to resistance-heat the manifold.

    Bob Wilson
     
  9. GrumpyCabbie

    GrumpyCabbie Senior Member

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    lol, off you go then. Practice what you preach. Sell the Volt or Prius and head off to work on your new electric scooter.

    Oh, you're circumstances don't allow that? You need a car for the same reasons the 1 billion other people on the planet 'need' one? Back to the drawing board then :)
     
  10. John H

    John H Senior Member

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    The Volt is my half step to the electric scooter. When the lease is over maybe I can make the other half step. I'm a recovering oil addict on a 12 step program. :)
     
  11. GrumpyCabbie

    GrumpyCabbie Senior Member

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    lol I like it. It's a good way of looking at it too.
     
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  12. John H

    John H Senior Member

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    I'm starting to realize that all the criticisms aimed at drivers in pickup trucks and suvs as a commuter vehicle seem to apply just as much to a 4 passenger sedan. 90% of my travel does not require me to transport anything other than myself. Convenient access to a sedan through a car sharing program or a cab for the remaining 10% works. I no longer need to operate a cab service for pre-teens as a second occupation.
     
  13. GrumpyCabbie

    GrumpyCabbie Senior Member

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  14. austingreen

    austingreen Senior Member

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    They make cars like that illegal in america:( We have safety regs that will prevent it. I wish we could change our safety regulations to be the same as Europe. I'm sure the prius would still stay as safe, but we could get some light cars like the twizzy.
     
  15. John H

    John H Senior Member

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    I would need just under 20 more mph to share the roadway I travel. The 31 mile range is a little shy of what I need as well. Maybe they will get to 50 miles and 70mph before my Volt lease expires.
     
  16. WE0H

    WE0H Senior Member

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    Get hit in that Twizy and you are history [​IMG]

    Mike
     
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  17. John H

    John H Senior Member

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    That's what my neighbors said when I got the Prius.
     
  18. WE0H

    WE0H Senior Member

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    A Prius would destroy the Twizy :) Prius is one of the safest vehicles you could drive.

    Mike [​IMG]
     
  19. NiHaoMike

    NiHaoMike Member

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    Couldn't they modify the design to have three wheels and call it a motorcycle?
     
  20. cwerdna

    cwerdna Senior Member

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    There is the Neighborhood Electric Vehicle - Wikipedia, the free encyclopedia. But, I haven't seen them used on the "open road". I remember seeing for use by campus staff at UCLA, the last time I was there (years ago).
     
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