Adaptive cruise

Discussion in 'Prime Main Forum (2017-Current)' started by Jzsquared, Oct 4, 2019.

  1. Jzsquared

    Jzsquared New Member

    Joined:
    Sep 14, 2019
    4
    0
    0
    Location:
    Chicagoland
    Vehicle:
    2020 Prius Prime
    Model:
    LE
    I was watching a review and they said when adaptive cruise is engage the engine will not shut off. Can anyone confirm this I use this option all the time in my current car and love it. I drive mostly highway but it goes from 45 to 70 depending on traffic but I would think this would hurt mileage some.
     
  2. alanclarkeau

    alanclarkeau Senior Member

    Joined:
    Feb 24, 2016
    6,134
    6,712
    0
    Location:
    near Brisbane, Australia
    Vehicle:
    2016 Prius
    Model:
    N/A
    It's definitely wrong if it says that.

    Though - you've put the question on the Gen 4 FORUM - but I'm certain that PRIME wouldn't either.
     
  3. meeder

    meeder Member

    Joined:
    Jul 8, 2019
    144
    98
    0
    Location:
    Doesburg
    Vehicle:
    Other Hybrid
    Model:
    N/A
    I does seem that the car is more hesitant to turn the engine off when driving a constant speed which is in the range of the EV mode. This could however be nothing more than a feeling. During traffic jams it shuts the engine off whenever it can do so.

    It doesn't seem to have to much of an effect on mileage. For me it causes it to neatly drive in EV mode during the last mile home through town.
     
  4. Jzsquared

    Jzsquared New Member

    Joined:
    Sep 14, 2019
    4
    0
    0
    Location:
    Chicagoland
    Vehicle:
    2020 Prius Prime
    Model:
    LE
    I was wondering about both because the standard should also turn on and off while going slower highway speeds especially on flat roads
     
  5. alanclarkeau

    alanclarkeau Senior Member

    Joined:
    Feb 24, 2016
    6,134
    6,712
    0
    Location:
    near Brisbane, Australia
    Vehicle:
    2016 Prius
    Model:
    N/A
    Yes, that it does. I drove home from Church just then - 30 km mixed traffic, but used DRCC most of the way - reads out 30% EV mode when I got home. Would have been the same if I'd driven it without DRCC.
     
  6. Curlyone

    Curlyone Member

    Joined:
    Sep 10, 2018
    50
    60
    0
    Location:
    Arkansas
    Vehicle:
    2018 Tesla Model 3
    Model:
    N/A
    completely false.
    You can confirm this yourself. The next time you are using cruise control, in the info screen choose energy. You will see the engine charging the battery, and when it builds up enough charge the engine shuts off for a bit. The cruise being on or off doesnt change that.
    I actually find it interesting to see how the car is making the decision on when to charge, use power, etc.
     
  7. jerrymildred

    jerrymildred Senior Member

    Joined:
    Oct 28, 2016
    8,336
    10,181
    0
    Location:
    Tampa, FL
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    I can also state from personal observation that that claim was false. Engine behaves exactly the same in either cruise control mode as well as with CC turned off. In fact, I cannot think of a single reason for the engine to be forced on just because the DRCC is on. Makes no sense at all.
     
    alanclarkeau likes this.
  8. meeder

    meeder Member

    Joined:
    Jul 8, 2019
    144
    98
    0
    Location:
    Doesburg
    Vehicle:
    Other Hybrid
    Model:
    N/A
    What I have seen on my Corolla is that when I drive without CC is that when I reach 80km/h (50mph) and I lift the throttle a bit it directly goes into EV mode. When using the CC to accelerate to 80km/h it doesn't do that. In the end it doesn't matter since whenever possible it runs in EV mode and for the rest the ICE is running.
    I don't have any data on it but I don't think that it has any effect on mileage.
     
  9. robsnyder20

    robsnyder20 Active Member

    Joined:
    Aug 13, 2012
    296
    240
    0
    Location:
    SW Florida USA
    Vehicle:
    2016 Prius
    Model:
    Three
    I have a scangauge so I can confirm this is false. However, if the car needs to slow down in DRCC due to traffic slowing down, it will force start the engine to use engine braking. This would be an excellent feature if going down a mountain but in flat florida its not so useful. Usually I prefer the charge over engine braking myself.
     
  10. jerrymildred

    jerrymildred Senior Member

    Joined:
    Oct 28, 2016
    8,336
    10,181
    0
    Location:
    Tampa, FL
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    I can't say one way or the other for non-Primes, but there have been plenty of times someone has brake hard and I've even been cut off several times when on DRCC and it decelerated pretty hard. The engine never came on, but it did apply the brakes one time.
     
  11. m8547

    m8547 Senior Member

    Joined:
    Aug 8, 2018
    836
    547
    0
    Location:
    Colorado
    Vehicle:
    2018 Prius Prime
    Model:
    Prime Plus
    Not quite exactly the same. There are weird conditions related to battery temperature and state of charge when the engine will start if you turn on cruise control even if everything is otherwise right for EV mode.

    Also, once the engine has warmed up, if cruise control is set the engine does seem to run more often at times when it wouldn't necessarily run if you were driving manually. Similar to how a traditional automatic transmission car seems more likely to downshift with cruise control on.

    That is my experience too.
     
  12. jerrymildred

    jerrymildred Senior Member

    Joined:
    Oct 28, 2016
    8,336
    10,181
    0
    Location:
    Tampa, FL
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    My engine has only come on in EV twice. Once when I accidentally used the defroster and the other time (in Colorado, btw) when the engine came on in EV mode and I think that was heat. We were coming down the north side of Grand Mesa, the SOC had gone from 10% to 98% in just a few miles, and I think it just got to the temperature limit.
     
Loading...