Environmental News

Discussion in 'Environmental Discussion' started by tochatihu, Oct 22, 2015.

  1. fuzzy1

    fuzzy1 Senior Member

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    "And even with the utility factor completely accounted for, the real-life to estimate gap still exists. That’s because plug-in hybrids are never fully electric, Gimbert said.

    Even in electric mode, the car continues to rely partially on hybrid mode. That is, the researchers found that PHEVs are not designed to operate fully in electric mode: the internal combustion engine still provides significant additional power and burns fossil fuels for at least one-third of the way when driving in electric mode. The engine especially assists the electric motor while accelerating, driving at higher speeds, or going uphill."


    Huh? What PHEV models are they referring to? My RAV4 Prime absolutely does operate in pure electric mode, never igniting the ICE for weeks at a time when I don't exceed its battery range. It can handle any hill around here in EV without the ICE. I do seem to remember the original Plug-In Prius (PIP) being prone to firing the ICE when greater power is needed, not so sure about the Prime-era models.

    That said, my "utility factor" is not as high their original estimate, and I never expected it to be, because of our retirement lifestyle with numerous road trips well off the developed recharging grid.

    I don't have time to fully recheck that, but at first blush, it seems too high. The rule of thumb I've used is that a gallon of gas puts out about 20 pounds of CO2, meaning a 20 mpg car should translate to 454 grams/mile, which converts to about 280 grams/mile.
     
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  2. tochatihu

    tochatihu Senior Member

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    I can attach a spreadsheet with 8.9 kg CO2 per gallon, and all other parameters in 'global' units.
     
  3. tochatihu

    tochatihu Senior Member

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    You are great. Prodded to find error, and now errr revise previous

    A 25 mpg vehicle emits 222 grams CO2 per km. Thus a 50 mpg vehicle, 111.
     
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  4. Trollbait

    Trollbait It's a D&D thing

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    Eh, the scandal is in EU regulators making to same mistake US ones did with E85 and flexfuel cars. They made high assumptions about how much of the alt fuel drivers would use while not having incentives in place to encourage use of the alt fuel. They ended up with PHEVs being bought for the incentives, but not being charged.
    It's a study of PHEVs in Europe. The power PHEVs from local makers are bigger sellers there. When this scandal first came to light a few years ago, the #1 or #2 selling PHEV model was a BMW SUV that may have been less efficient than the ICE version in hybrid mode. The other big seller was the Outlander PHEV, another not known for its efficiency.

    Then EV modes may not be the same between the US and EU model, in order to conserve EV range for zero emission zones.The PiP there had the engine come on at a lower speed, and the EU gen4 Prius PHV EV mode was the US EV Auto.
     
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  5. fuzzy1

    fuzzy1 Senior Member

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    That lands very close to the rule-of-thumb approximation I typically use.