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Oil Analysis Results- 25,000 Miles between changes

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by krousdb, Aug 21, 2009.

  1. krousdb

    krousdb NX-74205

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    A very good friend of mine, who worries way too much about me and my 2004 Prius, urged me to send my latest used oil to the lab for analysis.

    This was my second oil change in 50,000 miles. Each interval was 25,000 miles. My car has 180,000 miles on it currently. The Oil is Mobil 1 0W-20.

    Here is a picture of the new oil next to the old oil that was analyzed.
    [​IMG]

    Here is the report from Blackstone labs. I guess I can push it to 27,000 miles next time.:D
    [​IMG]
     
    #1 krousdb, Aug 21, 2009
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  2. jayman

    jayman Senior Member

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    I used to run Mobil 1 0W-20 16,000 km on the dealership oil filter. Oil analysis came back just fine, it was clearly good for much longer

    I appreciate you taking the time and money to have the oil sampled. It's good to provide "real" data to all the doomsayers out there who claim >5,000 miles will cause the motor to kerplode
     
    #2 jayman, Aug 21, 2009
  3. drees

    drees Senior Member

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    I agree with Blackstone on the insolubles, but they do look very good for 25k miles. Did you run the whole OCI on one filter?

    To me, it looks like the oil has thickened up a good deal (it's nearly a 30wt) despite having a touch of fuel in the oil. I'd say it's pretty close to being done.

    Otherwise, looks great! I'm chicken to run my Prius pass 7500 until it's out of warranty. Just using 5w30 M1 and whatever filter is available at the local auto store.
     
    #3 drees, Aug 21, 2009
  4. krousdb

    krousdb NX-74205

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    Yes, just one filter. Made by Fram.

    Interesting. I didn't notice that. Why would the oil thicken? I would expect it to become thinner.

    I agree. You are a chicken!:p
     
    #4 krousdb, Aug 21, 2009
  5. efusco

    efusco Moderator Emeritus
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    You gotta love that personal touch of "Next time try 27k miles"!! I bet they were showing that result all around the lab!
    I've been doing 10k mile changes without sending for UOA the last couple of times. I think I'll send one off at my 100k mile change in about 8-9 months just as a little "lab test" for my ICE health.

    What I think is blatantly clear here is that those of us who drive gently/hypermile can FAR exceed the recommended 5k mile changes very safely with no risk to anything but our warranty.
     
    #5 efusco, Aug 21, 2009
  6. krousdb

    krousdb NX-74205

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    Evan,
    You hit the nail on the head! Compared to a non hybrid, a hypermiling Prius jockey has two advantages. In the city, only about half of my miles are with the ICE running. On the highway, normally I drive 55. The ICE lopes along at 1400-1600 RPM. In both cases, the rotations per mile is a about 50% of a normal ICE. Why not expect twice the miles between changes?
     
    #6 krousdb, Aug 21, 2009
  7. vertex

    vertex Active Member

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    As I've said before on this site, I have used Mobil 1 for decades, and change oil and filter 1 time a year, with 15 to 20K miles and have had no problems. This report justifies what I have been doing. I clearly remember that when this oil was introduced Mobil recommended 25K between changes.
     
    #7 vertex, Aug 21, 2009
  8. efusco

    efusco Moderator Emeritus
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    I think I can safely say that of the 90k miles I have on my Prius that the ICE has run only 45k of those miles. On my normal commute I rarely exceed 40% ICE-on percentage. And, as you say, even on the highway, unless you're really punishing it, the ICE runs very gently/smoothly.

    You just never have those "hard on the engine" situations like a conventional ICE must endure. Once I surpass 100k miles I may stretch my oil changes to an annual event (I average 15-17k miles per year).
     
    #8 efusco, Aug 21, 2009
  9. tochatihu

    tochatihu Senior Member

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    Maybe somebody wants to take another shot at compiling the PriusChat used engine oil analyses? The Mobil 0W20 I recall seeing were mid or low-range for viscosity. It's hard to get too excited about this one at the high end of range though.

    You are going to get some grief for the Fram filter though. It is a brand that people love to hate.

    No doubt drivers that work hard to keep the ICE unloaded could also lower engine wear. But I was pretty tough on Tochatihu from time to time, and could never get any interesting engine wear metals. The darn thing is just built right. By that I mean accurate metal cutting, and engineered to limit transient loads on the ICE.
     
    #9 tochatihu, Aug 21, 2009
  10. FireEngineer

    FireEngineer Active Member

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    Dan if your not going to change the filter as well as the oil then use a larger filter. The Mobil 1 oil filter M1-209 fits fine and has almost twice the filtration capacity of the little OEM sized one.

    Wayne

    Who didn't even mention Fram.
     
    #10 FireEngineer, Aug 21, 2009
  11. efusco

    efusco Moderator Emeritus
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    I've been using FRAM filter's too, my UOAs were beautiful after 10k miles. It would take one heck of a good filter to convince me of a need to change.
     
    #11 efusco, Aug 21, 2009
  12. krousdb

    krousdb NX-74205

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    As I have said before, I had purposefully chosen Fram to prove a point. Even the worst is good enough.

    The current oil is running through a Toyota Oil filter. Just because I got two of them recently for $3 each.
     
    #12 krousdb, Aug 22, 2009
  13. tochatihu

    tochatihu Senior Member

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    Oh well if we can't get anyone to yell at you here about Fram, suggest you post the whole story at BITOG. Another group with too much time on their hands :)
     
    #13 tochatihu, Aug 22, 2009
  14. jayman

    jayman Senior Member

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    Although I personally don't use Fram, I'd like to modify your statement:

    "Even the worst is better than none at all"
     
    #14 jayman, Aug 22, 2009
  15. krousdb

    krousdb NX-74205

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    I've been there a few times. I have to admit that I didn't understand a thing. I think I prefer not being yelled at. Unless I really deserve it.:p
     
    #15 krousdb, Aug 22, 2009
  16. jayman

    jayman Senior Member

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    I enjoy being yelled at. I also enjoy leather and painful .... oh wait a minute, I'm thinking about something else.

    Nevermind
     
    #16 jayman, Aug 23, 2009
  17. drees

    drees Senior Member

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    Typically, you'll see the oil thin out a bit as the viscosity index agents shear down. This is usually most noticeable between 2500-3500 miles from the UOAs that I've seen (also on BITOG).

    Then what happens is over time, the heat of the engine "cooks" off the lightest parts of the oil. As a result, viscosity will start thickening up - usually after 5000-7500 miles or so.

    Note that I'm talking about good oils here. Crap oils can/will start thickening up much sooner which is can leads to sludge formation when combined with certain operation conditions and engines as Toyota has seen.
     
    #17 drees, Aug 24, 2009
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