Adaptive cruise control following distance

Discussion in 'Gen 3 Prius Main Forum' started by BrianPB, May 22, 2014.

  1. BrianPB

    BrianPB Member

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    Hey Priuschat for those of you who have the adaptive cruse, what do you think about the following distance and which setting do you use? I don't really like to use the ACC because even at the closest setting, I think it follows too far. Which is about 4 car lengths at 70 mph. People always seem to be cutting in front of me and the car keeps slowing down to increase the distance then speeding up to get back to speed. And when it does speed up I think it uses the throttle too much(accelerating faster than I would like to). What are your thoughts on the system??
     
  2. David Beale

    David Beale Senior Member

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    I find it works just fine on setting #2 and gives me the 2 sec. distance. Yes, morons will cut in. Would you rather hit the guy in front or allow the morons to do their thing? We have fault insurance here, and hitting someone in the rear is 100% your fault.
    Maybe it's not the thing on the California freeways.
     
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  3. hybridbear

    hybridbear Member

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    Does the Owner's Manual specify what the following distance is of each setting? We don't have that feature in our Prius, but we do in our Fusion Hybrid. In the Fusion Hybrid the longest following distance is about 2.7 seconds at 62 MPH according to the OM. On the freeway I don't like to follow any closer for safety reasons. In Driver's Ed we were taught a 3 second following distance minimum. Our weather is so crazy in MN that I usually try to keep a 3+ second following distance on dry roads and even more when the weather is bad.
     
  4. JimN

    JimN Let the games begin!

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    At 15' four car lengths are 60'. At 60mph the car travels 88 feet per second. When something happens can a driver stop or avoid the vehicle in front within 0.68 second? Many people just don't maintain a safe following distance.

    I agree that it accelerates too quickly and I feel it brakes too sharply.
     
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  5. Alan Claver

    Alan Claver Junior Member

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    Exactly the opposite. The follow distance even on the longest setting is too far for safe distancing at higher speeds. A number of roads in my area have safe following markings on them (large dots) and without fail my Prius 2013 doesn't allow enough distance at speeds over 55 mph.

    If you're using the medium or close distance you're looking for trouble.
     
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  6. BrianPB

    BrianPB Member

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    Same here, if you hit someone from behind its your fault. But, I think I could be following a little closer and still be able to react. But your'e right better safe than sorry.
     
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  7. BrianPB

    BrianPB Member

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    The manual says the following distance is 100 feet at 50 mph with the shortest setting, and that the distance increases/decreases with vehicle speed. Here in LA if you're following too far people are constantly cutting in front of you :/ on a side note, how do you like your fusion compared to the Prius? I test drove one and loved the smooth ride, it felt like a luxury car to me.
     
  8. BrianPB

    BrianPB Member

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    A driver can't come to a complete stop, but if the vehicle in front of you is traveling at the same speed, and you are aware of whats happening ahead, you still have enough time to react. At least that has been my experience.

    It would be cool if they could adapt the ACC to the drive mode you have selected and Accelerate accordingly. If you are in power mode it could accelerate quickly, in eco a little more leisurely and normal mode, somewhere in between.
     
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  9. BrianPB

    BrianPB Member

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    I think if it wasn't safe Toyota wouldn't have it set up that way, This is the same company that wont let me or a passenger enter a destination while the car is in motion. But I respect your opinion, you would rather be safe than sorry, I get it. :)
     
  10. macman408

    macman408 Electron Guidance Counselor

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    I typically use it on medium, but will switch it to short when somebody cuts in, or to the far setting if I'm approaching a slower-moving car and want it to slow down more gradually. When accelerating, I'll switch it to the longer settings just as it starts accelerating hard, so that keeps it from accelerating too quickly for my taste.

    There are many people in CA that will cut in even on the short setting; but I avoid most of them by not driving during rush hour. At other times, it's a little less crowded, and I don't have as many problems with people cutting in.
     
  11. cproaudio

    cproaudio Speedlock Overrider

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    I always use the default 3 bar and follow behind a big rig. Sometimes 2 bars. No one wants to cut behind a big rig anyway. I find that the closer the following distance, the more aggressive braking and acceleration.
     
  12. hybridbear

    hybridbear Member

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    We really like it. It's much more comfortable than the Prius.We would never take the Prius on a long trip because the comfort level isn't there. The interior is all hard plastic in the Prius and the seats are uncomfortable. The Fusion interior is all soft touch materials and the seats are comfortable even after spending 16 hours in them in one day on a road trip.

    We average 40 MPG in the winter & 50-55 MPG in the summer in the Fusion. The Prius averages about 42 MPG in the winter and 50-55 MPG in the summer. The Prius doesn't seem to have a huge drop in MPG on the freeway compared to in the city. The FFH drops more at freeway speeds. But we've gotten 44-45 MPG on 4500 mile road trips in the Fusion, so it still does quite well at 65+ MPH. All those MPG numbers are based on the pump and not the dash display.
     
  13. Mendel Leisk

    Mendel Leisk Senior Member

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  14. Dtronic

    Dtronic Junior Member

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    I have been using the 1 bar, but I think it brakes too hard. This is in multi lane Florida 55+ stoplight driving. I If I was on an actual highway, I think I would use the 3 bar.

    I am very good at judging closing speeds and the speeds of drivers around me so I usually know when they car in front of me should be braking or not.
     
  15. dhancock

    dhancock 2 Prius Family

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    I've probably driven 45K with the DCC on our 2011 and usually use the closest setting - particularly in heavy traffic. I've found that the system reacts (and brakes) much faster than I can when some a-hole cuts in (we have plenty of experience with that in Chicago rush-hour traffic). Also, keep in mind, that the PCS is also active and definitely will apply heavy braking if a collision is eminent. I've had that happen a couple of times (around Chicago, of course ;) )

    I often use the middle setting when on winding country roads, and poor road conditions. Only use the longest setting when I am in no rush and sticking strictly to the right lane.

    Regarding accelerating too fast: Yes it does (a bit) - but (at least in the 2011) if YOU depress the gas pedal to get the acceleration you want, that overrides the system.
     
  16. BrianPB

    BrianPB Member

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  17. BrianPB

    BrianPB Member

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    image.jpg
    The three photos are at 70 mph, going from shortest setting to longest setting top to bottom
     
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  18. BrianPB

    BrianPB Member

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    It does react pretty quickly and I have experienced the PCS a couple of times too, what an awesome feature! I didn't know you could control the acceleration I'll have to give that a try. :)
     
  19. 32kcolors

    32kcolors Senior Member

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    I use the shortest one because otherwise other cars will just cut in front of me. Not surprisingly since this is L.A. traffic we're talking about.
     
  20. Alan Claver

    Alan Claver Junior Member

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    Funny but I went back to my owners manual and I MISSED the note that the follow distance changes based on the car speed. I'm glad I looked. In that case you are probably right that Toyota is using recommended follow distances for safe follow.

    Always glad to learn something new and admit if I've been wrong or mistaken.

    Here's the relevant section from my 2013 Prius manual:

    Vehicle-to-vehicle distance settings. Select a distance from the table below. Note that the distances shown correspond to a vehicle speed of 50 mph (80 km/h). Vehicle-to-vehicle distance increases/decreases in accordance with vehicle speed.

    Distance options


    Vehicle-to-vehicle distance

    Long


    Approximately 160 ft. (50 m)

    Medium


    Approximately 130 ft. (40 m)

    Short


    Approximately 100 ft. (30 m)
     
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