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Denso plugs ONLY!....

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Dino33ca, Dec 29, 2014.

  1. Dino33ca

    Dino33ca Member

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    Says the spark plug commisar at our local dealership! This after I book a time for plug and pcv change. I tell the service guy that I've got my own plugs NGK iridiums (#4996, IFR5T11) from Amazon. He then tells me that It's not a good idea to go with iridiums as a number of Tundra drivers have gone this route and have been disappointed to the extent that they have had to replace these 'specialty' plugs. The fellow then says that the dealership only stocks Denso plugs and they wouldn't be able to guarantee my satisfaction. Meanwhile the service lady in the back overhearing this starts shaking her head and rolling her eyes, yelling out... They've got to be gapped... They've got to be gapped!

    I don't believe these plus (IFR5T11) have to be gapped as a number of posters here have used them. I'm almost wondering if I should have stayed with the stock Densos. I got 205k kms out of the first set. If I get the same on the second set I'd be perfectly fine with it. I got the NGK's because they were highly rated and I got them for a good deal through Amazon. Any one know if these do have to be gapped. Thanks in advance...



     
  2. JC91006

    JC91006 Senior Member

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    If you buy the correct Denso plug, they will also be iridium. So what's the guy's point?

    They come already gapped to the right specs. You can double check them but I have never encountered one that not gapped properly.
     
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  3. uart

    uart Senior Member

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    Hi Dino. The NGK IFR5T11 is the direct replacement for the IFR5A11 (now discontinued), which was the Prius OEM sparkplug in many regions. My 2005 Prius came with these NGK plugs from new, and they lasted over 200,000 km without any problem.

    The service guy is just spinning you a line because they'd prefer to make a lot of money selling you the parts at a marked up price. Provided that you have the genuine* NGK part, they are every bit as good (no better / no worse) as the Denso part.

    *BTW. Watch out for counterfeit parts. With the explosion in ebay and other online retailing there's been a big problem with counterfeit parts recently. See this link for details on spotting a counterfeit plug: PLUG STUDIO / NGK
     
    #3 uart, Dec 29, 2014
    Last edited: Dec 29, 2014
  4. Dino33ca

    Dino33ca Member

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    Thanks Uart. Good to know. I'll tell the service guy I've got oem plugs. I'll double check the packaging. They're from Amazon.com so you'd think they would be the real deal but I'll investigate further....
     
  5. exstudent

    exstudent Senior Member

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    If the plugs are truly supplied by Amazon and shipped by Amazon, then most likely genuine. However, Amazon also allows sellers to stock their merchandise in an Amazon warehouse, with Amazon charging the seller rent and shipping. The latter could allow for imitation parts to be shipped by Amazon, unknowingly, since Amazon is shipping what the seller provided.

    Perhaps find a local, big chain, auto parts store, that has the same part number NGK plug for comparison purposes.
     
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  6. Patrick Wong

    Patrick Wong DIY Enthusiast

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    1. Bringing your own parts to a dealer service department and asking for them to be installed is like bringing your own steak to a restaurant and asking that it be broiled. Don't do that. If you are going to buy your own parts then install them yourself, or find an independent garage willing to work with you.

    2. The correct spark plug gap is 1.0 to 1.1 mm and the plug gap should be checked prior to installation. I use 1.0 mm to maximize the service life of the newly installed plugs.

    3. NGK IFR5T11 is the correct model, if the plugs are genuine then no worries. Either the correct Denso (as specified in the owner's manual) or NGK iridium spark plug that you bought would be perfectly satisfactory. Beware of some "performance" iridium plugs which will have a shorter service life because they do not have a platinum tip on the ground electrode.
     
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