Prius versus Corolla Engines

Discussion in 'Gen 3 Prius Main Forum' started by Emad, Aug 10, 2016.

  1. Emad

    Emad Junior Member

    Joined:
    Aug 5, 2016
    15
    3
    0
    Location:
    Jordan
    Vehicle:
    2014 Prius
    Model:
    One
    Hello all,

    I have a tiny question.

    After I bought my prius last week and search on the net about its specs, I found that there is something weird in the engine.

    Prius gasoline engine (2ZR-FXE) with 1800 CC displacement produces 98 HP and 140 N.M, and the whole hybrid system produces 134 HP.

    Comparing to the same size corolla engine (2ZR-FE) with 1800 CC displacement produces 132 HP and 170 N.M.

    The difference between the two gasoline engine is the corolla engine produces 34 HP than the gasoline engine in prius, also it produces more tourque.


    The question is, why would Toyota use a less power engine with same displacement in prius, why they didn’t use the same corolla engine in prius to produce more power from the hybrid system?


    My Best Regards,

    Emad
     
  2. fotomoto

    fotomoto Senior Member

    Joined:
    Apr 22, 2009
    5,244
    3,488
    0
    Location:
    So. Texas
    Vehicle:
    Other Hybrid
    The corolla is an otto cycle while the prius is an atkinson cycle. Search those terms for a better understanding of Toyota's choices.
     
  3. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    89,993
    40,369
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    congrats and welcome! emissions and l/km.
     
  4. gliderman

    gliderman Active Member

    Joined:
    Aug 2, 2011
    746
    210
    0
    Location:
    Texas
    Vehicle:
    2010 Prius
    Model:
    IV
    The goal of the Prius is not high power. It is economy, more MPG. It is a delicate balance which they pull off quite well.
     
    Felt likes this.
  5. JimboPalmer

    JimboPalmer Tsar of all the Rushers

    Joined:
    Apr 14, 2009
    12,144
    6,494
    2
    Location:
    Greenwood MS USA
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    The Atkinson cycle engine in the Prius converts 40% of the energy into motion, the rest becomes heat.
    The Otto cycle in the Corolla converts 25% of the energy into motion, the rest becomes heat.

    If you do not care about MPG, the Otto cycle engine would bolt right in.
     
    Emad likes this.
  6. fuzzy1

    fuzzy1 Senior Member

    Joined:
    Feb 26, 2009
    14,027
    7,562
    90
    Location:
    Western Washington
    Vehicle:
    2012 Prius
    Model:
    Three
    Along the same lines as above, the Prius engine scores 50 MPG on the U.S. scale, while the Corolla engine scores only 31 to 32 MPG in a smaller, lighter car.
     
  7. CR94

    CR94 Senior Member

    Joined:
    Dec 2, 2014
    1,747
    667
    0
    Location:
    Northwestern S.C.
    Vehicle:
    2011 Prius
    Model:
    Two
    Those two engines are very similar, except the valve timing (and electrically vs. belt-driven water pump and compressor).
    BUT ...
    Is the Corolla version as susceptible to excessive oil consumption and clogging of its EGR system after it accumulates a few miles?
     
  8. qdllc

    qdllc Senior Member

    Joined:
    Aug 25, 2013
    1,309
    377
    0
    Vehicle:
    2013 Prius
    Model:
    Two
    Also, never equate CC with HP. HP is the product of how a motor works as a whole. Displacement (CC) is just a measurement of how much combustion space a motor employs. Motorcycles "tweak" HP output all the time by tuning the fuel map, intake and exhaust systems. A less restrictive exhaust system can massively boost HP output.
     
    Emad likes this.
  9. JimboPalmer

    JimboPalmer Tsar of all the Rushers

    Joined:
    Apr 14, 2009
    12,144
    6,494
    2
    Location:
    Greenwood MS USA
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    CC is a particularly bad way to look at an Atkinson cycle engine as the intake valves do not close near bottom dead center, but about 1/3 of the way up the cylinder, so the captured fuel/air is a much smaller number of CCs than the full stroke measured. This is why the Prius engine has a 'compression' ratio (actually it expansion ratio) of 13:1 but runs on regular gas and acts like its compression ratio is 8:1 (because that is all the air it trapped)
     
    Robert Holt, fuzzy1 and Felt like this.
  10. JimboPalmer

    JimboPalmer Tsar of all the Rushers

    Joined:
    Apr 14, 2009
    12,144
    6,494
    2
    Location:
    Greenwood MS USA
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    The Atkinson Cycle has a great many issues that make the Otto cycle more appealing to Manufacturers.

    Low HP per CC
    Low torque at low RPMs
    Limited RPM range

    As designed by Toyota, the 50 to 80 HP electric motor hides many of these issues.
    An electric motor produces maximum torque at 0 RPMs
    Electric HP needs less build up time, it seems stronger because you did not wait for it.
    Infinite gear ratios hide the limited RPM range in normal use.

    Proponents of a Diesel hybrid, do not factor in the differences needed to mask the weaknesses of a Diesel which are not the same.

    Diesels tend to really hate start-stop, A theoretical M/G1 will need to be MUCH bigger to start a Diesel over and over.
    Diesels change RPM very slowly. You are going to need to be able to change the speed of M/G2 not lock it to wheel speed like the Prius.

    Most 'real' Diesel Hybrids run the engine at a fixed speed to make electricity (and perhaps charge a battery) and propel the vehicle entirely with motors.
     
    Emad likes this.
  11. jfschultz

    jfschultz Active Member

    Joined:
    Mar 15, 2004
    635
    112
    0
    Location:
    Germantown, TN
    Vehicle:
    2013 Prius Plug-in
    Model:
    Plug-in Base
    The Atkinson Cycle works well with a steady load and speed. The Otto Cycle does much better over a range of load and speed needed for the automotive use. The short compression, long expansion of the Atkinson Cycle means that more power to obtained per unit of fuel and so is much more efficient. To work in an automotive application it needs to be augmented by the electric motor.
     
    Emad likes this.
  12. CR94

    CR94 Senior Member

    Joined:
    Dec 2, 2014
    1,747
    667
    0
    Location:
    Northwestern S.C.
    Vehicle:
    2011 Prius
    Model:
    Two
    Except that it isn't augmented in the 3rd generation much, unless you're whipping it hard. That's why battery charge level normally does not drop significantly when I climb long hills. Instead of relying on energy from the battery to make up for the low engine torque, the system uses more engine revolutions than would be necessary to get up the hill with most Otto-cycle cars---even modestly powered ones. That strategy can be noisy, but is better in the long run than unnecessarily exercising the battery to accomplish the same result.
     
    Maarten28 likes this.
  13. jfschultz

    jfschultz Active Member

    Joined:
    Mar 15, 2004
    635
    112
    0
    Location:
    Germantown, TN
    Vehicle:
    2013 Prius Plug-in
    Model:
    Plug-in Base
    I suspect that in this situation that there is not much change in the SOC is because MG1 is generating the electricity to be used by MG2 to augment the ICE and may have surplus to feed to the battery. (The energy screen should show this.)
     
  14. Maarten28

    Maarten28 Active Member

    Joined:
    Jul 13, 2014
    382
    187
    1
    Location:
    Netherlands
    Vehicle:
    2011 Prius
    Model:
    Three
    And what is supplying MG1 with the energy to generate electricity? The ICE. If the ICE would not do that, it could rev less.
     
  15. Coast Cruiser

    Coast Cruiser Senior Member

    Joined:
    Mar 12, 2016
    2,267
    2,557
    0
    Location:
    Pacific Coast Highway
    Vehicle:
    2016 Prius
    Model:
    Three
    When I'm doing 80 in my Prius on the freeway? I keep seeing new Corolla's blowing by me! :LOL: And Honda Fit's... it's like I'm standing still... at 80. It's crazy.
     
  16. CR94

    CR94 Senior Member

    Joined:
    Dec 2, 2014
    1,747
    667
    0
    Location:
    Northwestern S.C.
    Vehicle:
    2011 Prius
    Model:
    Two
    But then you won't get up the hill, unless the battery supplies sufficient energy to MG2. That wouldn't be good.
     
  17. Metalman

    Metalman Member

    Joined:
    Dec 27, 2010
    107
    17
    0
    Location:
    Summer, KY; Winter FL
    Vehicle:
    2010 Prius
    Model:
    II
    That's understandable. Most Prius owners are interested in conserving fuel (not necessarily at 80 mph though), but drivers of non hybrids are normally not so MPG conscious. In some areas speed limits are simply recommended speeds so let her rip!
     
    Coast Cruiser likes this.
  18. Emad

    Emad Junior Member

    Joined:
    Aug 5, 2016
    15
    3
    0
    Location:
    Jordan
    Vehicle:
    2014 Prius
    Model:
    One
    Thank you all for your precious replies. :)
     
Loading...