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What oil do you use in your Prius?

Discussion in 'Gen 2 Prius Main Forum' started by rwmt6161, Apr 8, 2008.

  1. ZC1

    ZC1 Junior Prius Owner

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    You kinky girl, YOU!
     
  2. jayman

    jayman Senior Member

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    Jen

    Due to the server problems I haven't been able to login since Friday. I just sent you a PM

    Hope you're getting better

    To minimize issues with the dealership, use the 5W-30. No point getting into a long - and ultimately futile - debate with them over the fact the Prius in Europe specs a wide range of viscosity, or the difference between North American API specs and European ACEA specs: they'll just hear whaa whaaaa wha whaaaaaa like Charlie Brown's teacher

    In summer temps, I've never noticed any difference in fuel economy running 0W-30, 5W-30, 0W-30, etc. A very minor difference - about 2 mpg less - running 15W-40 heavy duty oil in summer temps

    The big difference is in winter

    Remember that with engine friction, the effect on fuel economy isn't as dramatic as you might think. A maker of extremely large - the size of an average house - industrial V-16 engines, Waukesha, experimented with different piston rings and other changes.

    Reducing engine friction 50% reduced fuel consumption 5%, but they had problems with oil consumption. That sort of motor would be used to run a +5 MW generator, a pipeline compressor station, etc. Those folks also care about fuel consumption

    The primary reason I went to 0W-20, or 0W-30, for winter was the fact my temps can dip to -40. Even though I park in a heated garage, I wanted the proven low temp performance of such synthetic oils

    Mobil 1 5W-30 should be good to -40, though if you were to consistently operate at -40 a 0W-30, especially a 0W-20, would be far more appropriate. So don't worry about that trip

    Good observation about whether they will use your own oil. I've posted the virgin oil analysis of that wonderful "Toyota spec" dealer bulk oil, I wouldn't use that s*** in an old broken down lawnmower

    Makes one wonder why Toyota got burned by an engine sludge class action suit, and why they universially lowered the North American oil change interval from 12 months/7,500 miles to 6 months/5,000 miles.

    The European Toyota spec remains at 12 months or 10,000 miles

    The only way to know for sure if they use your oil is if you watch every step. I'm not saying every dealership is a scam artist, but enough are to make me suspicious

    Remember that even current API SM/ILSAC GF-4 will *not* prevent ring land deposits, crown land deposits, cold gellation, or cold sludge, as there is no specific requirement to do so. The ACEA spec oils *do* have to minimise/prevent those sort of deposits

    Mobil 1 5W-30 is dual rated API/ACEA. Don't waste your money on the Extended Performance, it carries the same ACEA ratings

    If you really want an superior ACEA oil, consider Mobil 1 0W-40, which is the oil I use in my FJ Cruiser. It meets the toughest ACEA specs: A3, B3/B4. Around here, priced the same as the other Mobil 1 oils. I don't think you need an oil like that in the Prius

    Running Mobil 1 0W-20 up to 16,000 km and 12 months, the oil tested fine
     
  3. jayman

    jayman Senior Member

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    I see I wasn't the only person thinking that ...
     
  4. ShaAnn

    ShaAnn Member

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    Great work finding out about the oil properties......I need to have my oil changed and will think about what to use......