Lowest RPM's at highway speed?

Discussion in 'Gen 4 Prius Technical Discussion' started by tzx4, Mar 23, 2018.

  1. tzx4

    tzx4 Active Member

    Joined:
    Feb 24, 2013
    164
    148
    0
    Vehicle:
    2016 Prius
    Model:
    Two
    That's the question. Anybody here have the technical knowledge of the generation four powertrain?
    I marveled at how relatively quiet the Prius is at 80 on well maintained, Autobahn quality pavement, (unlike the s**tty bounce, bang, and roar roads here in Colorado) and unless I was on an uphill grade, how the motor is not audible, which made me wonder just how low can the RPMs be at that speed?
     
    pilotgrrl likes this.
  2. alanclarkeau

    alanclarkeau Senior Member

    Joined:
    Feb 24, 2016
    6,138
    6,712
    0
    Location:
    near Brisbane, Australia
    Vehicle:
    2016 Prius
    Model:
    N/A
    Probably in EV mode at that stage - it selects what is appropriate for the condition. The Hybrid Synergy Drive's main drive is by way of the 2 Motor/Generators, with the Petrol motor kicking in and running at whatever speed it needs to.

    G
     
    RCO likes this.
  3. Fester

    Fester Active Member

    Joined:
    Mar 29, 2010
    186
    180
    0
    Location:
    Ohio
    Vehicle:
    2017 Prius
    Model:
    Two
    I don't go 80 mph, but next time I'm driving I'll check my ScanGauges for RPM. I do seem to recall a number of around 3200 RPM around 60, but I'll check to confirm.
     
  4. JimboPalmer

    JimboPalmer Tsar of all the Rushers

    Joined:
    Apr 14, 2009
    12,137
    6,474
    2
    Location:
    Greenwood MS USA
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    I drive a lot at 61 mph in a v, 1700 is doing well, 1500 is minimum.
     
  5. jerrymildred

    jerrymildred Senior Member

    Joined:
    Oct 28, 2016
    8,336
    10,187
    0
    Location:
    Tampa, FL
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    Here's a look at the transaxle if you haven't already seen it.
    Weber State on Prius transmissions | PriusChat
     
    alanclarkeau likes this.
  6. alanclarkeau

    alanclarkeau Senior Member

    Joined:
    Feb 24, 2016
    6,138
    6,712
    0
    Location:
    near Brisbane, Australia
    Vehicle:
    2016 Prius
    Model:
    N/A
    I seem to remember someone posting (could have been Gen 2 or 3) a long time back, that the RPM varies continually on the highway - it's either off, or about 1500 up to in the 4000s, but that depended on the topography. It was someone with a ScanGauge.
     
    RCO and jerrymildred like this.
  7. Tideland Prius

    Tideland Prius Moderator of the North
    Staff Member

    Joined:
    Oct 2, 2004
    41,421
    12,963
    41
    Location:
    Canada
    Vehicle:
    2018 Prius Prime
    Model:
    Technology
    That seems a bit high if one is cruising on a flat road at 60mph. At 60, I'd wager it's closer to 1,300rpm.

    3,200rpm sounds like 5th gear in a close-ratio compact sport sedan (like a Corolla XRS with the 2ZZ-FE for example)
     
  8. Fester

    Fester Active Member

    Joined:
    Mar 29, 2010
    186
    180
    0
    Location:
    Ohio
    Vehicle:
    2017 Prius
    Model:
    Two
    Checked today at 60mph and the scan gauge indicated about 2088 rpm.
     
    RCO and Tideland Prius like this.
  9. alanclarkeau

    alanclarkeau Senior Member

    Joined:
    Feb 24, 2016
    6,138
    6,712
    0
    Location:
    near Brisbane, Australia
    Vehicle:
    2016 Prius
    Model:
    N/A
    Uphill, down, level (relatively)?

    Interesting if it sat steady, as from what I read about Hybrid Synergy drive, it's unlikely to sit steady for more than a few seconds. It is supposed to be dependent on Battery Charge, battery temperature, terrain, speed and load - rather than on one factor. WIKI says "an HSD transmission continuously adjusts the effective gear ratio between the engine and the wheels to maintain the engine speed while the wheels increase their rotational speed during acceleration."

    Before I bought my PRIUS, someone on PriusChat posted this simulator:

    Toyota Prius - Power Split Device
     
    Fester and RCO like this.
  10. JimboPalmer

    JimboPalmer Tsar of all the Rushers

    Joined:
    Apr 14, 2009
    12,137
    6,474
    2
    Location:
    Greenwood MS USA
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    I live in the Mississippi Delta, very flat. (it gains 90 feet in 156 miles, 30 meters in 250 km) Even if you take terrain and speed out of the picture, (cruise control for 55 miles) RPMs vary with temp, wind speed, rain, engine temp, etc. It is never stable day to day and varies in the third digit on a given day.
     
    alanclarkeau and RCO like this.
  11. Fester

    Fester Active Member

    Joined:
    Mar 29, 2010
    186
    180
    0
    Location:
    Ohio
    Vehicle:
    2017 Prius
    Model:
    Two
    That was on the flat while accelerating to 60 mph so that the ICE was actively providing power. I primarily drive rural roads with a fair number of moderately sized hills. I can always tell if I'm in EV mode, as the ScanGauge will go to 0 RPM.
     
    alanclarkeau likes this.
  12. tzx4

    tzx4 Active Member

    Joined:
    Feb 24, 2013
    164
    148
    0
    Vehicle:
    2016 Prius
    Model:
    Two
    Hmm, now I want a scanguage just to see how low the RPM can go at any given speed, and how low they can go before the system just shuts the ICE motor down and runs on battery.
     
  13. JimboPalmer

    JimboPalmer Tsar of all the Rushers

    Joined:
    Apr 14, 2009
    12,137
    6,474
    2
    Location:
    Greenwood MS USA
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    My v idles at 1280, but can run as low as 960 RPMs.
     
    fuzzy1 likes this.
  14. fuzzy1

    fuzzy1 Senior Member

    Joined:
    Feb 26, 2009
    13,917
    7,470
    90
    Location:
    Western Washington
    Vehicle:
    2012 Prius
    Model:
    Three
    Same as my '12 Liftback, though that idle speed is cold, not warm.
    I.e. accelerating, not steady speed. It should drop significantly lower for steady cruising, unless you are going slightly uphill, or into a strong headwind.

    To answer OP's question, at highway speed, the RPM can be anywhere between redline and slowest idle, depending on conditions. The Prius HSD's engine RPM is not directly linked to road speed as it is in traditional transmissions.

    My Gen3 normally runs 1200 to 1600 RPM on the level roads I frequent. Gen4 shouldn't run any higher.
     
    #14 fuzzy1, Mar 30, 2018
    Last edited: Mar 30, 2018
    bat4255, RCO and alanclarkeau like this.
  15. jerrymildred

    jerrymildred Senior Member

    Joined:
    Oct 28, 2016
    8,336
    10,187
    0
    Location:
    Tampa, FL
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    If you don't want to spend that much, there are lots of inexpensive ELM27 OBDII devices that will give you that info on your phone with either the Torq or Engine Link app.
     
    jtv, pilotgrrl, RCO and 1 other person like this.
  16. Fester

    Fester Active Member

    Joined:
    Mar 29, 2010
    186
    180
    0
    Location:
    Ohio
    Vehicle:
    2017 Prius
    Model:
    Two
    Although ScanGauges are a bit pricey, they do have the advantage of not having to be disconnected when the car is off as they automatically power down when the ignition is turned off, and also display continuously. I find it very useful to be able to monitor voltages, temps, and even individual tire pressures, which can give you an indication that something might be amiss before you get a warning light.
     
    jerrymildred likes this.
  17. RCO

    RCO Senior Member

    Joined:
    Aug 31, 2016
    3,709
    5,165
    0
    Location:
    Cornwall
    Vehicle:
    Other Hybrid
    Model:
    N/A
    I bet there's a crystal ball on your Christmas wishlist. ;)
     
    pilotgrrl and jerrymildred like this.
  18. TheClassic

    TheClassic Junior Member

    Joined:
    Apr 1, 2018
    4
    5
    0
    Location:
    US
    Vehicle:
    2018 Prius
    Model:
    Two
    A CVT has a min and max ratio between which it is continuously variable. I believe this should define the engine speed range at a given wheel speed.
    There may be other factors that I don't know about such as the coupling technology between engine and transmission, but the CVT itself shouldn't prevent an RPM range from being calculated.

    Just bought my Prius yesterday!

    Posted via the PriusChat mobile app.
     
  19. john1701a

    john1701a Prius Guru

    Joined:
    Jan 6, 2004
    11,948
    4,666
    57
    Location:
    Minnesota
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    Here's an example of what you can do with that $10 reader and $5 app:



    That's my Prime, shortly before it runs out of plug-supplied electricity. Following that is warm-up, then a jump onto the highway.

    In this next video, I added data for engine-load. There's lots of other informative gauges available. In this case, I wanted to show what happens when charge-mode is engaged... something you can't do with the regular Prius, but you get the idea:

     
    #19 john1701a, Apr 1, 2018
    Last edited: Apr 1, 2018
    RCO, jerrymildred and alanclarkeau like this.
  20. Lucifer

    Lucifer Senior Member

    Joined:
    Aug 23, 2015
    1,011
    481
    0
    Location:
    Nh
    Vehicle:
    2017 Prius Prime
    Model:
    Plug-in Advanced
    Yes, grab a scangauge, it will check codes in any car, and reset them, great company to deal with if you have any future problems, and they are constantly upgrading their product.

    For example, if your tires are undersized and your speedometer is inaccurate, the scangauge can make the adjustment to the electronics to give you the correct speedometer reading.
     
    RCO likes this.
Loading...