Oill consumption and oil weight

Discussion in 'Gen 3 Prius Main Forum' started by CK9887, Mar 15, 2017.

  1. CK9887

    CK9887 Junior Member

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    I have a 2010 with 105K miles... It's burning oil at rate of roughly 1qt every 3-4k miles. Currently using the factory recommended 0w-20 full synthetic.

    Would switching to a heavier weight oil help with consumption? I considered going to a 10w-30 to see if that made any difference. I realize I might see a slight decrease in MPG's, but I'm okay with this if it slows down oil consumption. Would there be any adverse affects of going to a heavier weight, other than the decrease in MPG?

    Thanks
     
  2. Paul Schenck

    Paul Schenck Active Member

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    The heavier weight would increase friction and lower gas mileage wouldn't it. Well I drove mine adding the quart from 300 to 397 K miles, it did clog my catalytic converter too. I'd say burn it and shop for one of those $600 engines on eBay ? The engineering makes the engine swap a breeze


    iPhone ?
     
  3. tpenny67

    tpenny67 Active Member

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    Assuming you're changing your oil every 10K miles, you're only adding 2 quarts between each change. Using a thicker oil probably won't stop the consumption, so at best it may get you down to 1 quart between changes.

    The biggest downside to thicker oil is that it doesn't flow well in cold weather. You appear to be from Texas so we can ignore that. :)

    Also keep in mind that in the old days, when oil changes were done about every 3K miles, your car would count as "doesn't use any oil". When you drive around with a case of oil in the back seat, then you're consuming oil.
     
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  4. mmmodem

    mmmodem Taste Tester

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    People always seem to forget this when they start complaining that their Prius is the only car they've ever owned that consumes oil.

    Anyway, the loss in fuel economy is a drop in the bucket when moving up a grade or two in oil thickness. You'll likely not notice a difference. I'd start with high mileage oil and see if that improves things before ramping up thickness. 10w30 will be fine.
     
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  5. Mendel Leisk

    Mendel Leisk Sunday driver DIY’r

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    Me, I'd change the weight first, use high mileage as last resort. The high mileage oils will swell seals, it's somewhat akin to putting the car on methadone maintenance: if you go back to regular oil the seals will shrink back and oil consumption will likely skyrocket.
     
  6. CK9887

    CK9887 Junior Member

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    Yea, living here in Texas, we wont see anything close to freezing temps until next winter. So I may give the 10w-30 full synthetic a shot and keep an eye on the consumption. If no difference, I will go back to the 0w-20.
     
  7. tonycd

    tonycd Member

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    Mendel is a veteran of this board and I'm not, so take that into account, but I'll respectfully disagree. Heavier oil will have slightly more trouble passing through the small holes and spaces in your engine, and high mileage oil (at a lower viscosity) will not. That makes high mileage oil a slightly better choice for lowering consumption while still protecting against engine wear.

    On the other hand, Prii with engines identical to ours come with a Toyota factory recommendation for heavier weight oil than the U.S. Prius does. This has been discussed on other threads here, but the short version is Toyota is legally obligated to recommend the same weight of oil that it uses when certifying the car's EPA gas mileage, and Toyota runs lightweight 0w-20 oil in order to eke out every last bit of reduced friction to get a high number. So, 10w-30 is not that far from what Toyota admits elsewhere is an appropriate oil weight anyway.

    Personally, I'd try the high mileage version of 5w-30 oil first. If it works, just keep using it forever. Based on the results others have reported here, I'd hope for some improvement but expect something less than a miracle.
     
  8. Raytheeagle

    Raytheeagle Senior Member

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    I switched to 5w-30 full synthetic about 30 k miles ago to quell oil consumption on our 2010 Prius II that now has almost 151 k miles on it. I was (key word;)) consuming at a rate of a quart every 4,500 miles. I then switched to thicker oil, drive a little slower (5-10 mph over the limit rather than 10-15 mph) and have used an engine flush and oil additive to the fresh oil.

    I have a little over 9 k miles since the last oil change and have consumed 20 ounces :).

    Next oil change is going to be BG Products EPR flush prior to draining the old oil, then Pennzoil Pure Platinum 5w-30 full synthetic with BG Products Extended Life MOA. Hopefully done on Saturday the 25th, but we'll see if that is in the cards or not.
     
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  9. CK9887

    CK9887 Junior Member

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    More info on the engine flush additive ?

    Just add it to the oil at a certain mile before the next oil change? How many miles is recommended to drive with the additive before changing the oil and flushing it out ? I have heard of people doing this with sea foam, but not familiar with the product you mentioned, although I'm sure there are multiple products out there with the same purpose.

    Thanks
     
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  10. Raytheeagle

    Raytheeagle Senior Member

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    Engine flush is BG Products EPR:
    IMG_0092.JPG IMG_0093.JPG

    Put this in prior to draining the engine. Run the Prius for about 10 minutes in "maintenance mode" at idle. Drain the oil. You'll see a much deeper black than usual:).

    This is the oil additive Extended Life MOA:
    IMG_0088.JPG IMG_0089.JPG
    Supposed to help keep the oil basic and help fend off the affects of gas contamination in the oil creating an acidic environment.

    I also use their 44K once a year as a fuel system cleaner:
    IMG_0086.JPG IMG_0087.JPG

    Here's a thread where I shared some info from a BG Products rep in regards to the above Products:

    [POLL] Excessive Oil Usage

    Hope that helps and answers your question(y).
     
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  11. CK9887

    CK9887 Junior Member

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    Cool, thanks for the info. I'll have to give it a shot.

    One more question, how do I put the prius in maintenance mode and what does this do?

    Thanks
     
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  12. Raytheeagle

    Raytheeagle Senior Member

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    You can search maintenance mode and it will return results. It invloves a "chicken dance" but not that hard to do. I wrote the instructions down and keep it in the glove box when needed (along with "invalid mode");).

    Maintenance Mode allows the engine to run like a normal car. You shouldn't drive the car in this mode. This can be beneficial for many different reasons.

    Keep us posted (y)
     
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