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    PNorth Junior Member

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    Location:
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    My dealer told me the other day that they're recommending using 5W20 oil for the engine. The manual recommends 5W30.

    As I bought a couple of jugs of the Mobil 1 5W30 on sale earlier, I'm going to use them, but does anyone know why Toyota has changed their recommendation for oil?

    Many thanks!
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    richard schumacher shortbus driver

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    "Dealer" does not equal "Toyota". Maybe that dealer has too much 5W20 in stock and they want to get rid of it. But users here do report that 5W20 seems to work fine in cold weather.
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    Politburo Active Member

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    AFAICT, Toyota has not changed the oil weight recommendation for the 2004-2009 Prius.

    Your dealer is possibly misreading a TSB, or is blurring the truth to save some money (I think many have changed their bulk system to 5w20).

    http://priuschat.com/forums/gen-ii-...62-toyota-now-recommends-5w-20-most-cars.html

    The above link indicates that 5w-30 should still be used for Gen II Prius. However someone working at a dealer claims Toyota has authorized 5w-20 in Gen II Prius, but does not provide any citation.

    http://priuschat.com/forums/gen-iii...leshooting/62662-oil-change-8.html#post918486
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    PNorth Junior Member

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    So... maybe it's just best that I use up the 2 jugs of 5W30 that I have, and if more info comes out later that 5W20 is better, then switch to that?

    Thanks for the input guys! Just curious about it...
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    jayman Senior Member

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    AFAIK the GenII Prius still requires a 5W-30. I checked at All Data, there is no TSB suggesting a 5W-20 on the 2004-2009 Prius. There is a TSB from 2007, stating a 5W-30 must be used

    I used Mobil 1 0W-20 in my 2004 Prius, with good results. I also followed up with used oil analysis to verify everything was ok

    Some vehicles on the 5W-20 list, such as my FJ Cruiser, probably should not be on the list. I had very bad used oil analysis results running xW-20 in that motor. It also made a lot of valvetrain ticking noises on xW-20

    With the FJ, running Mobil 1 European Car Formula 0W-40, much better lab reports and the motor is quiet. Oddly enough, there was no difference whatsoever in fuel economy

    With my Prius, there was no difference in summer fuel economy running 0W-20. In winter, perhaps 2-4 mpg more
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    cnschult Active Member

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    I used Mobil 1 for years, perhaps 10 or 20 years ago they were the best, now I've made the switch to Pennzoil Platinum. (pennzoil conventional may be garbage, but their synthetic is I think the best avail)

    here's a hint: synthetic oil + toyota filter ($7 at dealership) = 11K miles coverage
    synthetic oil + Fram Extended Guard filter ($8 at walmart) = 15K miles coverage
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    rhk107 New Member

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    Im on my second oil change at 30k!!! :eek:
    First one was at 10k which was pushing it with stock oil.. :deadhorse:

    Luckily my last change was with Mobil 1 Synthetic 0W-20 with Mobil 1 Filter. :plane:

    I just go by my experience with Mobil 1 Synthetic.. it last a long time. :bounce:

    Oh yes, and I recommended a drop-in KN Filter just for the fact that its re-useable.


    And YES my prius is a rules!! :rockon:
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    jayman Senior Member

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    That may sound horrifying, but consider the same Prius sold in the EU will have its first scheduled service also at 10,000 miles. For cars sold in the EU, there is generally no early initial service

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