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

Spark Plus SC16HR11 Dense, is any using it and different??

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Tekken, Aug 28, 2019.

  1. Tekken

    Tekken Member

    Joined:
    Jul 9, 2019
    250
    74
    0
    Location:
    Los Angeles, California
    Vehicle:
    2013 Prius
    Model:
    Two
    Currently change all 4 of my original Sc20HR11 to Sc20HR11 on 2013 and apporx 4~5mpg decrease on Highway drive with ECO mode. EV with ECO combination under local drive about same. I was gapped that SC20HR11 at 1.04 ~ 1.05mm and No code or missed fire not noted.

    I have heard Toyota recommend SC16HR11 now and I've a set of 4 plus in hand. Should I try it out or should I back to Old plus. As most Iridium plus can survive 120k miles. My 2013 only has 94K and i'm assuming this old plus can last another 25k miles with slice better mileage.

    SC16HR11 is running hotter, what's it going to do if running hot?
     
  2. The Critic

    The Critic Resident Critic

    Joined:
    Oct 28, 2005
    3,193
    2,315
    0
    Location:
    CA
    Vehicle:
    2011 Prius
    Model:
    Three
    I am using the revised plugs in mine. No issues.
     
    Raytheeagle likes this.
  3. StarCaller

    StarCaller Senior Member

    Joined:
    Feb 15, 2014
    1,240
    692
    0
    Location:
    Cedar Crest, NM, USA
    Vehicle:
    2014 Prius
    Model:
    Two
    nothing is going to run hotter, the spark plug is called 'hotter', meaning the self-cleaning takes effect at a lower spark plug temperature /
     
    mjoo likes this.
  4. Robert Holt

    Robert Holt Senior Member

    Joined:
    Aug 3, 2013
    1,313
    888
    0
    Vehicle:
    2012 Prius
    Model:
    Three
    Uh, my experience is with 2-cycle and 4-cycle engines is that “hotter” plugs do run hotter where the arcing takes place at the tips and center electrode. A “too cold” plug would slowly accumulate carbon and ultimately fail when carbon bridged the gap or accumulated to the extent that the high voltage had an easier alternative pathway to ground and did not jump the gap.
    A “too hot” plug would typically have whitish deposits on the ceramic insulator around the center electrode, rather than light brown, and in extreme cases the center electrode would melt or the ceramic insulator would crack into pieces, which would pass out of the exhaust valve if you were lucky , or hang up the valve or crush into the top of the piston if you were unlucky. Further, the tip a “too hot” plug under load could get hot enough to act like a glow plug and cause pre-ignition of the fuel-air mixture before the spark occurred. If you were lucky you would just hear pinging as the mixture ignited essentially too early and you could reduce load in time to prevent damage. If unlucky, full scale detonation occurred where the mixture all ignites at once rather than having a nice, gradual flame front, and that would over-stress combustion chamber components both with heat and the shock of the explosions, resulting in burned valves, holes blown in piston crowns, and possibly cylinder scoring. Correct heat range depends in part on the loads you create with your style of driving, so I would check how your old plugs looked upon removal and select either hotter or colder plugs based on that evidence.
     
    Zeppo Shanski and mjoo like this.
  5. Tekken

    Tekken Member

    Joined:
    Jul 9, 2019
    250
    74
    0
    Location:
    Los Angeles, California
    Vehicle:
    2013 Prius
    Model:
    Two
    They all looking similar burned.. but was not drive by me. I have been drive like a grandma since bought this prius
    172461_20190818_212417_HDR.jpg 172462_20190818_212438_HDR.jpg
     
  6. mjoo

    mjoo Senior Member

    Joined:
    Nov 9, 2016
    1,105
    1,311
    12
    Location:
    Michigan
    Vehicle:
    2010 Prius
    Model:
    III
    More proof that the 2ZR-FXE generates more carbon than Toyota designed for?

    Pixel XL ?
     
  7. Robert Holt

    Robert Holt Senior Member

    Joined:
    Aug 3, 2013
    1,313
    888
    0
    Vehicle:
    2012 Prius
    Model:
    Three
    Not sure, mjoo, as carbon accumulation seems to depend on the extent of richness of the air-fuel mixture, the anti-deposit additives in the fuel mix (even Top Tier fuels differ in amount, types, and effectiveness of additives), combustion chamber temperatures, and extent of oil blow-by once the engine has significant ring or sidewall wear, or just stuck rings, and amount of the typical duty cycle the ICE and specifically the combustion chamber spends at low temps, I think.
     
  8. Robert Holt

    Robert Holt Senior Member

    Joined:
    Aug 3, 2013
    1,313
    888
    0
    Vehicle:
    2012 Prius
    Model:
    Three
    Not sure, mjoo, as carbon accumulation seems to depend on the extent of richness of the air-fuel mixture, the anti-deposit additives in the fuel mix (even Top Tier fuels differ in amount, types, and effectiveness of additives), combustion chamber temperatures, and extent of oil blow-by once the engine has significant ring or sidewall wear, or just stuck rings, and amount of the typical duty cycle the ICE and specifically the combustion chamber spends at low temps, I think.
     
  9. Robert Holt

    Robert Holt Senior Member

    Joined:
    Aug 3, 2013
    1,313
    888
    0
    Vehicle:
    2012 Prius
    Model:
    Three
    Not sure, mjoo, as carbon accumulation seems to depend on the extent of richness of the air-fuel mixture, the anti-deposit additives in the fuel mix (even Top Tier fuels differ in amount, types, and effectiveness of additives), combustion chamber temperatures, and extent of oil blow-by once the engine has significant ring or sidewall wear, or just stuck rings, and amount of the typical duty cycle the ICE and specifically the combustion chamber spends at low temps, I think.
     
  10. mjoo

    mjoo Senior Member

    Joined:
    Nov 9, 2016
    1,105
    1,311
    12
    Location:
    Michigan
    Vehicle:
    2010 Prius
    Model:
    III
    Well, I guess 3 posts beats my meager 1 post...
     
    RMB likes this.
  11. Grit

    Grit Senior Member

    Joined:
    Aug 22, 2017
    6,103
    4,032
    1
    Location:
    Wilkes Land
    Vehicle:
    2012 Prius
    Model:
    Four
    :ROFLMAO::ROFLMAO::ROFLMAO::ROFLMAO::ROFLMAO::ROFLMAO::ROFLMAO:
     
    RMB likes this.