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Safe to change to Synthetic?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by chasabel, Jan 22, 2005.

  1. chasabel

    chasabel Junior Member

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    Has the mileage been established on how long it takes to seat the rings in the ICE, so that one is comfortable in changing to synthetic oil?

    My oil dealer said not to run his premium synthetic oil until the rings
    seat because they wouldn't seat if I run the synthetic to soon.

    I have read where some have changed to synthetic at 600 miles some
    at 3000 some at 5000, others saying to wait until 10000 etc.

    I have read that current rings in cars are not like ones of yesteryear
    that took a certain amount of time to 'wear in' so the engine wouldn't
    use excess oil.

    Anyone know for sure?

    Frank Hudon have an opinion?
     
  2. Rick Grahn

    Rick Grahn New Member

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    I don't know for sure but I changed to synthetic at 1,000 miles.
     
  3. HTMLSpinnr

    HTMLSpinnr Super Moderator
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    I didn't switch to Synthetic until my last oil change at 25k miles, and at 40k miles on my classic (it had been over 6 months since 37.5k) - first change I've done myself on both cars and opted to go for Quaker State Full Synth to see if it made any difference. Seems to add 1-2 mpg but I haven't done anything scientific to prove this.
     
  4. jayman

    jayman Senior Member

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    For some reason, the Toyota dealers in this region recommend waiting 10,000km / 6,250mi before switching to synthetic. They claim this is the minimum break-in required for satisfactory performance, fuel economy, and oil consumption.

    They also recommend putting 5,000km on the initial oil, and to NOT change sooner. Next oil change at 8,000km. Another oil change at 10,000km.

    Then follow the recommended OCI and use synthetic at that time if you want.

    Sometime next week I'll have on 8,000km, so time for the second oil change. Have a coupon it will only cost $14. At 10K I'll do it myself and use Mobil 1 0W-30 year round.
     
  5. DWrath

    DWrath New Member

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    Yea, I'd like to know when I could switch over to synthetic. If oil changes are going for $60+ a pop at the dealer, I'd rather switch to synthetic and get my oil changed q. 10K as opposed to q. 3K. That'd save some money and time, which we all like to do. :wink:
     
  6. IsrAmeriPrius

    IsrAmeriPrius Progressive Member

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    That is one sure way to void your warranty.
     
  7. Frank Hudon

    Frank Hudon Senior Member

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    Chasabel I changed to Mobil 1 5/30 at my first oil change, and just changed again today. Most literature on modern piston rings favours that they are broken in at an early mileage. In the old day's the cylinder walls weren't honed as smooth as they are today, or as round. Also they tended to use cast rings and chrome oil scraper rings. On the modern engines they used moly filled rings for long life and they demand very smooth cylinder walls to properly seat the rings. So the time to full seat is very short compared to days of old. The most important items for proper lubrication are the camshaft and followers, be it lifters or rockers, and to get long life most manufactures use a break-in lube on the cams and associated parts. This is the reason for the recommended first change be at 3,000 plus miles. I'm more of a time rather than a mile change person and operating conditions are as important as mileage/time. My distance to work is about 27Km which is far enough to let the ICE and the MG's get to operating temp. 87-90C on the ICE and to the 40-60C range on the MG's This takes 25 minutes, so any moisture in the oil is evaporated. This keeps the acids down to a reasonable level. Now I've changed my wife's 2k4 to dino oil and maybe that's the reason that she can't get the mpg of my classic.
     
  8. jayman

    jayman Senior Member

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    Ditto. For whatever reason, 8,000km / 5,000mi max here in North America.

    There have been problems around here with the 3.0 V6 "sludge monsters" when folks followed the Toyota 8,000km OCI. A lot of that has to do with the rather poor oil specs for North America.

    A regular mineral 5W-30 operated under short trip, especially in -40 temps with severe condensation, will fall apart and sludge up the motor. A good synthetic 5W-30 or 0W-30 meeting ACEA A3/A5 specs will perform well.

    The folks around here who run quality synthetic lubes will go the full manufacturer recommended 8,000km without issue. If you run a conventional 5W-30, better change every 5,000km / 3,000mi max.

    By the end of next month, I should have 10,000km on the motor. I'll switch to Mobil 1 0W-30 and run it the full 8,000km.

    Here's something to consider: the Prius in Europe that run a synthetic 0W-40 are safe to 16,000km / 10,000mi. Mobil makes a very high quality synthetic 0W-40 but I don't think we can use it here in North America, despite the fact it's recommended in EU.