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New PB CT to Boston

Discussion in 'Gen 3 Prius Fuel Economy' started by Insight-I Owner, Aug 18, 2011.

  1. Insight-I Owner

    Insight-I Owner 2006 Insight-I MT + 2011 Prius

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    Actually it was 76.9mpg (figure 73.0 actual) but the battery was low after a traffic jam and city streets to get here, so the ICE started while I was trying to take my photos. That dragged the final number down by 0.1. Previous PB was 73.0mpg on the HSI. I had a south tailwind, which probably had something to do with it, plus humid mid-80's conditions. I don't know why but humidity seems to help mpg.

    I also made a lot of use of what I think is the SAHM mode discussed on cleanmpg. On the Scangauge I can see that the ICE is spinning at about 990rpm but it shows zero gas flow. It takes a delicate foot: very slight extra pressure on the gas initiates gas flow. This is for speeds >46mph where EV mode can't be accessed AFAIK.

    The average mph took a hit because I ran into heavy rush hour traffic on I-93 north out of Boston getting to Medford. Most of the time I was running at around 50mph (in the far right lane of course).
     

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  2. Bica2go

    Bica2go New Member

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    Pretty sweet!

    Yes, I-93 through Boston at rush hour can be a killer. I do all that I can to avoid that. I shudder just thinking about it.
     
  3. fuzzy1

    fuzzy1 Senior Member

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    I believe this is Warp Stealth mode, not SAHM. No gasoline is burned, but the ICE is spinning to protect MG1, and limited electric propulsion is available (true EV mode is limited to 25 mph). For best efficiency you shouldn't use much electric thrust while in this mode. But with no electric thrust -- HSI bar vanishing -- this is the perfect point for gliding in Pulse & Glide above 46 mph. Note also that some purists reserve the term 'Glide' for when RPM = 0, i.e. speeds below 46 mph, hence the extra term 'Warp Stealth'.

    SAHM is a gasoline burning mode of the ICE, usually in a fairly narrow range of TPS (throttle position) and IGN (ignition advance). I don't recall the particular numbers for Gen3, as it is less applicable here than to the Gen2 / Civic Hybrid / Insight, and does not fit much of my usual driving situations.
     
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  4. Insight-I Owner

    Insight-I Owner 2006 Insight-I MT + 2011 Prius

    Joined:
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    Location:
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    2011 Prius
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    Two
    Boy the terminology certainly is complex and not evocative! I thought I needed to be wearing a Darth Vader helmet to get into Warp Stealth.