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Cruise Control

Discussion in 'Gen 3 Prius Fuel Economy' started by markabele, Apr 18, 2012.

  1. markabele

    markabele owner of PiP, then Leaf, then Model 3

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    What are the most and least optimal times to use cruise control at highway speeds?
     
  2. Big Steve

    Big Steve ramblin wreck

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    This is, of course, a non-hybrid related question.

    I looked on line and found this:

    So one thing I think about when contemplating a long drive is how much money I am going to end up paying for gas. Since I am naturally cheap, I try and think of any way to spread out those stops between gas stations. One way to make gas last longer is to use cruise control. Actually, a study done by Edmunds.com found that you can save up to 14 percent by using cruise control, with the average driver saving around 7 percent. Of course, cruise control is great to use on a nice sunny day, but there are times you should not use cruise control.
    Never Use Cruise Control In the Following Situations:

    1. Driving in rain/snow/sleet. Driving with cruise control in wet conditions can cause wheel spin and a loss of control. Please warn your friends and family of this danger as it is not very well known.
    2. Driving in mountainous/hilly areas. Using cruise control in these situations will actually use MORE gas
    3. Driving when tired or fatigued. This is because the car will not slow down if you start to drift off for a second like it would if you were not using cruise control. (If you are tired to the point where you are drifting, you should not be on the road period.)
     
  3. markabele

    markabele owner of PiP, then Leaf, then Model 3

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    I disagree. I've heard it said that using cruise control in a Prius isn't near as good as it is on a regular car. I'm just curious what those reasons are.
     
  4. jdcollins5

    jdcollins5 Senior Member

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    What have you "heard" about a Prius cruise control that makes it not nearly as good on a regular car? The Prius cruise control works just like any other cruise control. You set the speed and it adjusts power output to maintain speed based on your terrain.

    I use my cruise control daily and it works just like any other cruise I have had.
     
  5. markabele

    markabele owner of PiP, then Leaf, then Model 3

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    I'm not saying it doesn't work like other cars. I'm saying I've heard it is not the absolute best thing to use in some cases for best gas mileage.
     
  6. Big Steve

    Big Steve ramblin wreck

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    I would think that using the Prius Cruise Control in
    1. Driving in mountainous/hilly areas. Using cruise control in these situations will actually use MORE gas
    could be much worse on mileage than what you could do manually to reduce the flucuations in throttle.
     
  7. jdcollins5

    jdcollins5 Senior Member

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    Oh OK, thanks for clarifying your question.

    Some will say it is better to drive without CC for best mpg. They will use pulse and glide techniques on open highways. They will also say to anticipate hills and increase speed prior to the hill so the engine does not have to work so hard and then to glide down the other side for max mpg. I will have to let others chime in with the details.

    I personally prefer the convenience of just setting the CC and enjoying the drive :)
     
  8. fuzzy1

    fuzzy1 Senior Member

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    I'd say that cc is not the absolute best thing in the vast majority of cases, in all cars.

    MPG varies considerably among drivers. CC is generally good for drivers on the low end of the mpg distribution, and possibly for those in the middle band. It is almost never good for drivers on the high end of the curve.
     
  9. Teakwood

    Teakwood Member

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    I disagree. I live in the Rockies. I use cruise control up and down hills regularly. Without even thinking about it, I get 52+ MPG when travelling in the mountains. It really works great on the downhill stretches.
    The only times I do not use CC is on windy roads, in poor visibility situations, and while travelling in town.
     
  10. er86

    er86 Junior Member

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    I also disagree as I just replaced my Sunfire with a Prius and going downhill in the Sunfire I would coast to a faster speed (and potential ticket) whereas the Prius will regen to reduce speed.
     
  11. dragonfinder1

    dragonfinder1 Junior Member

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    When I drive to Portland from home (90 miles each way) I can get better mileage at 75 mph without CC than at 70 mph with the use of CC. I've done it many times.
     
  12. HaveNoCents

    HaveNoCents Conservative Tree Hugger

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    Every time you go over an overpass with your car on cruise control will try to maintain its speed and give the car more gas. This is exactly what you are not supposed to do. If you hold steady on the gas until you reach the top and then glide down you will increase your mpg. To me the only time cc is ok is when you are on a long flat road, but you can always get better mileage not using it.
     
  13. mattheikkila

    mattheikkila New Member

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    Maybe on hilly roads it's not a great idea as far as mpg goes but on large hills that go uphill for a while, it's nice to just set it until you get near the top. Maybe I'll test it out the next couple times I go up hills I take on a daily basis.
     
  14. mad-dog-one

    mad-dog-one Prius Enthusiast

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    I appreciate the convenience of CC and, particulary, radar CC in our Prius V's, although I consistently get better mileage on the same route when I don't use CC., even without P&G.
     
  15. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    I live where it is dead flat, 60 foot gain in 156 miles, so CC works fine for me, as I never drive at a P&G speeds.

    Other conditions would reveal othter truths.
     
  16. ChipL

    ChipL Active Member

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    Unscientific, but a 100 mile r/t on the byways of Northern Va showed me that cruise control is not the best with the Prius. 50mpg using cruise vs a weekend trip showing 60mpg after the correction over my last r/t...
     
  17. Codyroo

    Codyroo Senior Member

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    For my 1989 Integra, I would coast down a steep local grade in neutral (5 speed) and would note my top speed and how far I could coast before I had to engage the car into gear and resume my 55 mph. There was a landmark I could hit as a reference point (an overpass). When the weather was warmer, I could coast further (and faster) than when the weather was colder. The few times I've driven that way in my Prius, I can go faster while coasting in D mode than I could in my Integra in neutral. I've not tried Gliding (pushing the gas pedal down to remove the small amount of engine brake) down that grade.....I'd be going WAY too fast, much faster than normal traffic runs while using their accelerator pedal.