Featured 2 New Toyota Hybrids To Be Revealed May 18

Discussion in 'Prius, Hybrid, EV and Alt-Fuel News' started by Tideland Prius, May 11, 2020.

  1. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    39,359
    27,994
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    I think the spare would be the same, if supplied. The OD's of the equipped tires are roughly the same, regardless of rim size.
     
    Tideland Prius likes this.
  2. Tideland Prius

    Tideland Prius Moderator of the North
    Staff Member

    Joined:
    Oct 2, 2004
    40,733
    12,299
    41
    Location:
    Canada
    Vehicle:
    2018 Prius Prime
    Model:
    Technology
    I don't know since I haven't seen it in person. I was thinking it could be mounted underneath the car as an option, that's all.

    Of course it would be great if it could be mounted under the floor and still have the 3rd row fold in, but I doubt it.

    Not for fuel economy purposes, though.
     
    #142 Tideland Prius, May 21, 2020
    Last edited: May 21, 2020
    Mendel Leisk and Salamander_King like this.
  3. telmo744

    telmo744 HSD fanatic

    Joined:
    Apr 8, 2010
    2,064
    692
    0
    Location:
    Portugal
    Vehicle:
    2010 Prius
    Model:
    N/A
    I was reading the abstracts, and many refer to the cold start period of PFIs.
    That says very little about the PM of fully warmed port injected engines, to properly comparing to diesels.
     
    #143 telmo744, May 22, 2020
    Last edited: May 22, 2020
  4. wxman

    wxman Active Member

    Joined:
    Nov 25, 2008
    613
    216
    0
    Location:
    Tennessee
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    Yes, most of those show high PN emissions @cold start or off-cycle ambient conditions. However, the firsts reference ( Real driving particle number (PN) emissions from China-6 compliant PFI and GDI hybrid electrical vehicles - ScienceDirect ) shows an entire RDE/PEMS test cycle. Note in the abstract:

    PFI engines have very low PN emissions except at engine start (cold or hot) and high engine load (e.g., heavy acceleration).

    An older paper comparing PN emissions from various engine technologies is available at https://publications.jrc.ec.europa.eu/repository/bitstream/111111111/26204/1/physical%20characterization%20of%20exhaust%20particle%20emissions%20from%20late%20technology%20gasoline%20vehicles%20_%20online.pdf . Note especially Figure 38 on page 47 which shows graphically the comparisons between the technologies.
     
  5. wjtracy

    wjtracy Senior Member

    Joined:
    Sep 19, 2006
    10,850
    3,331
    1
    Location:
    Northern VA (NoVA)
    Vehicle:
    2006 Prius
    In general, particulates is a hot button issue these days, because the Obama EPA said, in so many words, particulates have extreme high death rate. Furthermore they said, many contaminants can be assumed to be associated with particulates, therefore many contaminants are deadly even at trace levels. For example, mercury in coal regulations are based on assuming particulates are associated the mercury, this then allows an alarming high death rate calculation for mercury, but of course, mercury is bad due to mercury, and not due to exaggerated claims about particulate toxicity.

    This kind of logic leads to the popular US eco-conclusion that all combustion process are essentially deathly.
    This basic conclusion was stated by one college demonstrator in the recent Planet of the Humans directed by Michael Moore. So I feel like we need to get a better grip on reality. Yes tires probably make a lot of particulates.
     
  6. Trollbait

    Trollbait It's a D&D thing

    Joined:
    Feb 7, 2006
    14,941
    6,730
    0
    Location:
    eastern Pennsylvania
    Vehicle:
    Other Non-Hybrid
    upload_2020-5-22_9-59-27.png
    Figure 38: Comparison of the number emission rates of non-volatile particles measured with a PMP compliant CPC (horizontal axis) and a CPC with a d50 at 4.5 nm (vertical axis), over the NEDC. Different types of symbols correspond to different vehicle categories (cycle for G-DIs, rhombus for PFI, squares for DPFs and hexagons for CNG) with different shades corresponding to different vehicles, and different sizes to different PCRFs (the larger the size the larger the dilution). The numbers indicate the average percentage difference between the [email protected] and the PMP CPC results, followed by the minimum and maximum percentage differences in the parenthesis. The two dashed lines correspond to the 6×1011 #/km limit and are shown as a guideline.

    This was the test cycle used for the tests, Emission Test Cycles: Common Artemis Driving Cycles (CADC) It is one based upon modern real world drive cycles in Europe.

    The graph has results for DI with an exhaust filter(GPF), and the paper discussed a couple other methods in short of reducing particles from DI after that figure.

    The numbers above show the GPF working, and they didn't see a fuel economy penalty during the testing. In fact, the was a regular reduction of 1% to 3.5% for emitted CO2 with the filter. The exhaust temperatures before the filter, with injection of oxygen during deceleration fuel cut off probably means the filter was 'self' regenerating under the test cycle.

    Using E75 and E85 in a flexfuel DI showed reductions as high as 97% on the motorway(highway) portion of the test. CO2 emissions were also reduced 6% to 8%.

    They also tested an older dual port and direct injected engine(the older Lexus one?). Still had the cold start spike, but emitted particles were around the diesel limit once warmed up. It was a Euro 4 model, so it didn't need to meet a particle limit. A current engine tuned to meet that limit could do better.
     
    wxman likes this.
  7. mikefocke

    mikefocke Prius v Three 2012, Avalon 2011

    Joined:
    Nov 3, 2012
    2,735
    1,145
    0
    Location:
    Sanford, NC
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    All you have to do is drive a white car after a rain and you'll see all the tire particulates kicked up onto the back of the car. Even after 4" of rain the other day which you would think would wash the particulates away, a 5 mile trip and I had to wash the rear end of the car when I got home. Black grit.
     
  8. wxman

    wxman Active Member

    Joined:
    Nov 25, 2008
    613
    216
    0
    Location:
    Tennessee
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
  9. wxman

    wxman Active Member

    Joined:
    Nov 25, 2008
    613
    216
    0
    Location:
    Tennessee
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    Agree.

    According to https://uk-air.defra.gov.uk/assets/documents/reports/cat09/1907101151_20190709_Non_Exhaust_Emissions_typeset_Final.pdf , Figure 2 and Figure 3 on page 25, exhaust PM emissions will continue to become a smaller and smaller portion of traffic-generated PM10 and PM2.5, in Europe at least.
     
  10. Trollbait

    Trollbait It's a D&D thing

    Joined:
    Feb 7, 2006
    14,941
    6,730
    0
    Location:
    eastern Pennsylvania
    Vehicle:
    Other Non-Hybrid
    It is also the asphalt, brake dust, and whatever else has settled onto the road. Even with complete elimination of particle emissions from every component of the car, there will be the resuspension of dirt and dust with every passing of a vehicle along the road.
     
  11. austingreen

    austingreen Senior Member

    Joined:
    Nov 3, 2009
    12,733
    3,438
    0
    Location:
    Austin, TX, USA
    Vehicle:
    2018 Tesla Model 3
    Model:
    N/A
    All this particulate information makes my head spin a little.

    Let's take the excellent port and direct injection 2.5L engine used in these hybrids. They could add 2 tricks - variable valve control on the exhaust valves and electric warming of the catalyst. An MIT paper showed early exhaust valve closing and late intake valve opening helps reduce pm as retaining that exhaust gas helps warm up the engine while precisely metering direct injection for the full load combination of fresh air and warm exhaust. Adding electric heating of the catalyst allows low hydrocarbon exhaust during this cold start. Being a hybrid the battery can fill in to allow best engine speed for warm up and provide power for the heating of the catalyst.

    At lower rpm the engine will produce very low emissions in direct injection atkinson mode. At high loads it is likely cooled egr and port injection will be required to keep emissions low but the engine can run in multiple modes.

    Of course if pm is still a problem a particulate filter may be added, but since PM is going to be low it will likely last a long time.
     
    Tideland Prius likes this.
  12. Trollbait

    Trollbait It's a D&D thing

    Joined:
    Feb 7, 2006
    14,941
    6,730
    0
    Location:
    eastern Pennsylvania
    Vehicle:
    Other Non-Hybrid
    Yep, dual injection and other methods should work for the US without needing a GPF. We could a just switch the fuel supply over to all E75. But EPA Tier 3 is one of the ares where it is less strict that Europe's regulations. It does impose a particle limit on a gasoline cars, but is only concerned with particle mass(PM). Particle number(PN). that Europe also has limits on, is ignored.
     
  13. Prashanta

    Prashanta Active Member

    Joined:
    Oct 11, 2016
    100
    102
    0
    Location:
    Canada
    Vehicle:
    2017 Prius Prime
    Model:
    Technology
    How does Toyota manage this? Such different power figures, same engine?
     
  14. Trollbait

    Trollbait It's a D&D thing

    Joined:
    Feb 7, 2006
    14,941
    6,730
    0
    Location:
    eastern Pennsylvania
    Vehicle:
    Other Non-Hybrid
    Many(all?) auto makers manage this. Differences in intake, timing, compression, exhaust, etc. can result in changes. Just changing the tune, engine control programing, can be enough; that seems to be the only difference in the 3.5L between the F150 and Raptor, and it means another 75hp for the performance trim. With hybrids, engineers get motors and a battery in the mix of things to tinker with.

    PS: The 3.5L Ecoboost got dual port and direct injection in 2017.
     
    Prashanta and Tideland Prius like this.
  15. austingreen

    austingreen Senior Member

    Joined:
    Nov 3, 2009
    12,733
    3,438
    0
    Location:
    Austin, TX, USA
    Vehicle:
    2018 Tesla Model 3
    Model:
    N/A
    I believe the difference here is mainly electronics and perhaps battery and motor/generators but am not sure the specs of either of that last 2 items.

    For this specific engine slightly higher rpm gives the siena/Highlander 186 hp @6000 rpm versus the venza/Rav4 that is tuned to give max power at lower engine speeds 176 hp @ 5700 rpm. Using lower native compression (13:1 versus 14:1) and raising peak hp rpm 207 hp @6600 rpm in the avalon. All three tunes run in atkinson mode most of the time.
     
    #155 austingreen, May 27, 2020
    Last edited: May 27, 2020
    Prashanta and Tideland Prius like this.
  16. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    39,359
    27,994
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Could they have different cam shafts, different valve lifts, duration?
     
  17. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

    Joined:
    May 12, 2018
    3,381
    3,314
    1
    Location:
    Pennsylvania
    Vehicle:
    2018 Prius c
    Model:
    Two
    Sure- but keep in mind that pretty much everything on the road does variable intake cam phasing these days, and you can create a lot of differences just by altering the program code regulating that cam advance even if they all have the same profile cut into the metal.
     
    Mendel Leisk likes this.
  18. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    39,359
    27,994
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Our late Civic (06 Hybrid) had dual intake cams (low/high lift). Normally you'd use the low lift, but hydraulic oil pressure could shift over to the high lift cams. There was one overpass I'd always notice it kick in, like a turbo. :)
     
  19. austingreen

    austingreen Senior Member

    Joined:
    Nov 3, 2009
    12,733
    3,438
    0
    Location:
    Austin, TX, USA
    Vehicle:
    2018 Tesla Model 3
    Model:
    N/A
    They are probably mechanically exactly the same as toyota gives the engines the same number. The venza/rav4 hybrids appear to cut off the highest rpm and probably electronically change vvt on the intake valves slightly differently versus sienna/highlander. The difference in hp is just about exactly the difference in rpm, and the higher horsepower comes at the least efficient rpm. HP is the same @ peak torque 3600-5200 rpm.
     
    Mendel Leisk likes this.
  20. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

    Joined:
    May 12, 2018
    3,381
    3,314
    1
    Location:
    Pennsylvania
    Vehicle:
    2018 Prius c
    Model:
    Two
    Screen Shot 2020-05-27 at 12.47.24 PM.png
    [​IMG]
     
    Tideland Prius and Mendel Leisk like this.
Loading...