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Fuel Economy and Cruise Control

Discussion in 'Gen 2 Prius Fuel Economy' started by AfonsoSilva, May 25, 2005.

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Do you Use your Cruise Control?

  1. Yes

    0 vote(s)
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  2. No

    0 vote(s)
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  1. AfonsoSilva

    AfonsoSilva New Member

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    [font=Comic Sans MS:959a7e5187]Hello Everyone,

    My first message here, so please accept my apologies if this has been discussed previously:

    Does anybody have a solid opinion on whether using the cruise control is the best way to achieve maximum fuel economy on a highway?

    The way I am thinking about it, if I want to stay at a reasonably constant speed, then I should let the cruise control work the engines and it should do the best job of predicting when to throttle up and when to release the power.

    Thanks,

    Afonso Silva[/font:959a7e5187]
     
    #1 AfonsoSilva, May 25, 2005
  2. efusco

    efusco Moderator Emeritus
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    Yes, in general, CC is the best way, on the highway to 1)get optimal mpg and 2)maintain your sanity!

    Exceptions include hilly terrain where a very attentive driver can do better by anticipating terrain, using 'gliding' or neutral on downhills to gain speed and starting the gradual acceleration process when steep uphill areas approach. The only other exception would be if you were drafting another vehicle and needed to make subtle speed adjustments to safely maintain the draft.
     
    #2 efusco, May 25, 2005
  3. Tideland Prius

    Tideland Prius Moderator of the North
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    Yes if it's relatively flat and most highways are.
     
    #3 Tideland Prius, May 25, 2005
  4. Ray Moore

    Ray Moore Active Member

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    I agree with the sanity thing but actually if you really are into it, you can beat the cruise control, even on flat terrain. Use the force Luke.

    I agree with everything Evan said also, unless you are really trying to go for the last bit of MPG.

    If that is the case then you can help it a little by getting it slowly up to speed and then feather the pedal to just maintain the speed or very slowly decrease to keep the blue mileage bar at 75-100 MPG for a while and then slowly recover anything that you lost. That's really quite an effort though, compared to CC. If it keeps you from getting bored to play this little game, then I say, "Go for it!"
     
    #4 Ray Moore, May 25, 2005
  5. efusco

    efusco Moderator Emeritus
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    I should say that some of the 'old timer' Prius folks strongly believe in "Pulse Driving"...accelerating to speed at most efficient rate then coasting to let speed drop a few mph then repeating the cycle. In theory running the ICE only in it's most efficient range.

    I'm not sure I believe in this and find it to be totally impractical and fairly unsafe on all but the most open and non-trafficed roads.
     
    #5 efusco, May 25, 2005
  6. AfonsoSilva

    AfonsoSilva New Member

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    [font=Comic Sans MS:47304d3ef1]Thanks for all the replies. It makes sense that the CC does a good job, but I was nervous about it being wasteful in gas. In my wife\'s car, the CC pushes the gas pedal forward whenever we set it.

    Since we are all gas misers that hate taking a trip to the gas pump, it only makes sense to look for good ways to milk some more MPG!

    Thanks Again![/font:47304d3ef1]
     
    #6 AfonsoSilva, May 25, 2005
  7. TonyPSchaefer

    TonyPSchaefer Your Friendly Moderator
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    I've been to Germantown, MD. Drove from there to Thurmont on a regular basis for work at Camp #3 a few years back. If I remember correctly, some of the roads are relatively flat but there are spots, specifically heading up into PA where there are hills and the like. And those are what keep me from using the Prius around here (No. Illinois).

    I find that Priapus will increase effort to maintain speed up a hill. But I'm more willing to sacrifice speed to maintain MPG. Additionally, after cresting the hill at the set CC speed, Priapus slows himself down as to not exceed the set CC speed. I'd just as soon regen or feather the pedal for free-coasting and accelerate. DOn't get me wrong, when I'm long-hauling in the interstate, CC is a must. But for everyday commuting. Not for me.
     
    #7 TonyPSchaefer, May 26, 2005
  8. mlkco

    mlkco Member

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    AlfonsoSilva it is so thoughtful of you to be compassionate to the visually impared
     
    #8 mlkco, Oct 10, 2005
  9. c4

    c4 Active Member

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    For me, I find that cruise always gets *worse* mileage than manual driving.. My driving technique is driving to maintain 48 MPG or better for as much of the trip as possible using a bit of feathering, but it's definitely *not* pulse driving.. In my case, cruise always gets 2-5 MPG worse than when I'm driving manually.

    On the other hand, I find long distance driving in any car very fatiguing and I will use the cruise for some stretches and sacrifice some MPG simply for my own comfort..

    The Prius cruise operation is similar to every other cruise control I've used, but based on how the car feels when cruise is enabled, it seems to control more than just the accelerator pedal input (ie, its behaviour seems to indicate that the cruise subroutines have access to more than just the speed pulse and can vary some of the hybrid control parameters in addition to the accelerator pedal)... It would be a very interesting experiment to install one of those aftermarket cruise controls with a servo that moved the acclerator pedal and a tap off the speed pulse and compare the difference in performance- does the availability and control of additional hybrid parameters provide any improvements vs. the simple speed/accekerator pedal model..
     
    #9 c4, Oct 11, 2005
  10. canon

    canon New Member

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    I agree with Evan Fusco. The electronic CC is much more sensitive and faster in coordinating the minimum power needs with the conditions of the road. Exceptions would be in anticipating power demands for changing terrain.
     
    #10 canon, Oct 11, 2005
  11. Charles Suitt

    Charles Suitt Senior Member

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    :rolleyes: ALFONSO</span>

    Unless you figure we have extremely poor eyesight, use a smaller font... looks like you are <span style=\'color:red\'>YELLING     at us.

    I use Cruise Control all I can, even around town. I find it usually gets better mpg results than I can with my foot.
     
    #11 Charles Suitt, Oct 12, 2005
  12. Brian K

    Brian K New Member

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    For me using CC drops my mpg a few mpg (Maine). I use it in order to rest my foot/leg. I watch the mileage drop, go back to manual and get the average back up. My passengers see this as well. Well, OK, I bring it to their attention. I never use it on secondary roads, only on I95.

    ATTN: TOYOTA: If it was a less aggressive CC (user selectable) it'd work better.

    FWIW, it all hinges on where one lives. Interstates aren't "mostly level" unless one lives in a mostly level area. Railroad tracks are mostly level, roads don't need to be. Our Interstate isn't mostly level at all.

    Hmmm, I almost posted this then realized it just might work better than my foot at <40 mph. I haven't tried that but I will.
     
    #12 Brian K, Oct 29, 2005
  13. V8Cobrakid

    V8Cobrakid Green Handyman

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    someone needs to change their font

    I only use it on flat terrain.. and only if i'm tired of driving... so.. yes, i use it.. but no.. not very often. i think it does a shitty job.
     
    #13 V8Cobrakid, Feb 12, 2006
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