1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Should i go to higher viscosity oil?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Jim Caldwell, Oct 10, 2020.

  1. Jim Caldwell

    Jim Caldwell Member

    Joined:
    Mar 22, 2015
    142
    25
    0
    Location:
    Mathis
    Vehicle:
    2014 Prius
    Model:
    IV
    My 2010 prius has 177k miles.. Runs perfect. I use only mobil 1 0w-20 oil and replace every 7 or 8k miles. It burns about 1 liter in 6000 or 6500 miles. Iwas told that this isnt an abnormal oil usage for that meage, so i dont have one of the defective oil-burners, as some were for 2010 year. My question is: would it be advantageous to switch to a higher viscosity oil now on this high miles engine or not?
     
  2. orenji

    orenji Senior Member

    Joined:
    Aug 17, 2013
    5,884
    3,486
    0
    Vehicle:
    2010 Prius
    Model:
    Three
    I don’t know if it is needed, but I started using
    0w-40 weigh at around 60k miles. I have almost 120k miles and no oil usage. Have you cleaned your EGR?
     
    pjksr02 likes this.
  3. hill

    hill High Fiber Member

    Joined:
    Jun 23, 2005
    19,606
    8,036
    54
    Location:
    Montana & Nashville, TN
    Vehicle:
    2004 Prius
    Model:
    IV
    Do manufacturers recommend going to higher multi visc at some mileage point?
    upon last look ... isn't it still 0w-20 for most manufacturers?
    .
     
  4. orenji

    orenji Senior Member

    Joined:
    Aug 17, 2013
    5,884
    3,486
    0
    Vehicle:
    2010 Prius
    Model:
    Three
    Toyota’s recommendation in several countries is to run 40 weight or even 50 weight. 0W-20 is water and is to meet CAFE standards.
     
  5. hill

    hill High Fiber Member

    Joined:
    Jun 23, 2005
    19,606
    8,036
    54
    Location:
    Montana & Nashville, TN
    Vehicle:
    2004 Prius
    Model:
    IV
    oh
    still ... w/ property in 2 other states that get snow ... it's nice to know the visc can sometimes be on the thin side.
    :)
    .
     
  6. jzchen

    jzchen Newbie!

    Joined:
    Apr 9, 2012
    3,295
    1,005
    0
    Location:
    Arcadia, CA
    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    I'd use high mileage formulation 0W-20 rather than higher viscosity.

    moto g(7) power ?
     
  7. orenji

    orenji Senior Member

    Joined:
    Aug 17, 2013
    5,884
    3,486
    0
    Vehicle:
    2010 Prius
    Model:
    Three
    That’s what the 0 weight is for.
     
  8. orenji

    orenji Senior Member

    Joined:
    Aug 17, 2013
    5,884
    3,486
    0
    Vehicle:
    2010 Prius
    Model:
    Three
    If you like to swell your seals. Stick with normal.
     
  9. jzchen

    jzchen Newbie!

    Joined:
    Apr 9, 2012
    3,295
    1,005
    0
    Location:
    Arcadia, CA
    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    The first # "0" protects you when oil is cold, whether 0W-20 or 0W-40, 2nd # determines viscosity when oil warms up to operating temp.

    moto g(7) power ?
     
  10. orenji

    orenji Senior Member

    Joined:
    Aug 17, 2013
    5,884
    3,486
    0
    Vehicle:
    2010 Prius
    Model:
    Three
    And that’s the most important number at start up.
     
  11. Grit

    Grit Senior Member

    Joined:
    Aug 22, 2017
    6,103
    4,032
    1
    Location:
    Wilkes Land
    Vehicle:
    2012 Prius
    Model:
    Four
    o_O
     
  12. pjksr02

    pjksr02 Active Member

    Joined:
    Nov 2, 2009
    532
    225
    2
    Location:
    Connecticut
    Vehicle:
    2010 Prius
    Model:
    III
    Don't miss the post about the EGR system. Ignore the EGR and you won't have to worry about the oil in your Prius anymore.

    There's also 0W-30 oil, if you don't want to go up to 40...
     
    Mendel Leisk likes this.
  13. jzchen

    jzchen Newbie!

    Joined:
    Apr 9, 2012
    3,295
    1,005
    0
    Location:
    Arcadia, CA
    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    Engine starts and stops a lot in a Prius. So after warm up your engine is trying to pump 40W oil when it was originally pumping 20W. But it's good to know that 40W and 50W are actually recommended in other countries. I did not know that. Thank you.

    moto g(7) power ?
     
  14. abdullah arslan

    Joined:
    Nov 19, 2019
    180
    77
    0
    Location:
    46628
    Vehicle:
    2010 Prius
    Model:
    V
    My 2010 prius is on 248k, burns similar or maybe a bit more than yours, I think use what recommended and just add 1qt or so 5w-30 when you add oil.
    And it's better to top-off 0w-20 during cold season and thick one in warm season.
    Normally I use high mileage one, but after this winter I ll give a try to 0w-30 for summer

    Posted via the PriusChat mobile app.
     
  15. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,475
    38,106
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    That's "moderate" consumption, definitely something going on there, valve seals or piston rings. Maybe a clogging PCV valve as well? If the rate is steady maybe not worth chasing, other than trying the various liquid fixes.

    Like other responders, since you don't mention EGR: it's definitely due for an inspection/cleaning. As it clogs the engine combustion chamber temps rise, never good.
     
    Michael Wood likes this.
  16. Michael Wood

    Michael Wood Active Member

    Joined:
    Jun 19, 2016
    179
    118
    3
    Location:
    Boston, MA
    Vehicle:
    2020 Prius Prime
    Model:
    LE
    I'm thinking that the best decision might be to go in the other direction - and to use the new 0w16 recommended for Gen 4's. Walmart is carrying the Mobil 1 version. I'm not sure that CAFE standards are all that motivated this move from 0w20 to 0w16. I'm guessing that detergents, additives, and flow properties related to low-emissions, start/stop, and other Hybrid ICE stress played a bigger role. When these Prius engines are doing their stop/start cycles in 10 degree weather, a 40 or 50 weight oil is pretty heavy. Mobil 1's consumer data on 0w16 puts an emphasis on cold flow, fast protection, and active cleaning agents that are hard to use in thicker oil. I'd be interested to see what countries are seeing recommendations for heavy oils in tight tolerance, low-emission engines. Toyota's not going to spend money back-spec'ing older vehicles....but it's fun to speculate

    I'm from the 1970s 10w40 days, so I love thick heavy motor oil as much as anybody. But I'm not sure we're in Kansas anymore.
     
    #16 Michael Wood, Oct 11, 2020
    Last edited: Oct 11, 2020
    Jim Swart likes this.
  17. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,475
    38,106
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    5W30 was the gen 2 spec. Couldn't hurt to try that for an oil change.
     
    Michael Wood likes this.
  18. Grit

    Grit Senior Member

    Joined:
    Aug 22, 2017
    6,103
    4,032
    1
    Location:
    Wilkes Land
    Vehicle:
    2012 Prius
    Model:
    Four
    :LOL::LOL::LOL::LOL:
     
    StarCaller likes this.
  19. orenji

    orenji Senior Member

    Joined:
    Aug 17, 2013
    5,884
    3,486
    0
    Vehicle:
    2010 Prius
    Model:
    Three
    Your engine will never cool down to the point that 40 weight is gonna thicken up to be restricted in flowing, especially in normal stop and go traffic.
     
    Michael Wood and gliderman like this.
  20. jzchen

    jzchen Newbie!

    Joined:
    Apr 9, 2012
    3,295
    1,005
    0
    Location:
    Arcadia, CA
    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    I checked a Mexican owners manual for was it a Yaris? Quite interesting practicing my Spanish.... Sure enough up to 20W-50 but for high ambient temps. Chart on p 302 I believe...

    moto g(7) power ?
     
    orenji and Michael Wood like this.