So I read previously about how there are some counterfeit plugs out there and was wondering if the group can take a look at these pics and let me know if I should put these in my car or not, possibly this weekend. They were bought off eBay at a price which only seems fit for fakes, but here's to hoping I got a good deal instead. Also, I know that these plugs are supposedly pre-gapped to the correct specs, what is the consensus on checking/regapping, because I've also heard that factory gapped plugs aren't gapped correctly all the time. Thanks!
Well check the gap first. And yeah, they should be correctly gapped at the outset: I've always checked them, and NEVER found one off. Also, I seem to recall at least one the manufacturers (NGK?) caution against adjusting the gap. Not sure how you tell counterfeit, how prevalent they are, and what the differences would be.
yeah, i bought a set if plugs on ebay at low cost and 3 of 4 were previously used (slightly, maybe a store return?) and looked a bit funny. i thought they were fake too and returned them. bought the authentic ones from advance auto for only several more $. in retrospect, turned out the ebay ones were legit. i deleted the pictures by now, but yours look OK to me. edit: wait, where is the iridium on the ground? aren't these supposed to be double iridiums.
IF......it quacks like a duck............ How often are you going to change plugs ? Maybe every 5 years ? Is it really worth the gamble just to save a few bucks ?? Sometimes these "deals" end up costing you more in the end. Did you check with known reputable auto parts dealers, either locally or via the Internet ? Their price might not be that much different than the "unknown" ones.
From the 2010 owner's manual, it says the plugs are DENSO SC20HR11, yours say SC16HR11. Also JAPAN is embossed on your plugs but the package says MADE IN CHINA. Use your best judgement. They're "probably" okay to use, but as mentioned, for how infrequently they are changed I would go with parts from a reputable dealer.
[QUOTE="yours say SC16HR11. [/QUOTE] SC16HR11 is the part number for a later plug, and is legit. In fact, it is the current plug called for by Toyota. (I still would not buy those; why skimp on such a critical part, that also lasts for 100,00 miles?)
I'm the one who recently posted the “after” pics of the counterfeit iridium plugs with 30k miles on them and the electrodes were essentially gone — worse than I’d expect of standard cheap Champion plugs at that mileage. The car ran fine for the first 20k miles with those plugs. If you don’t mind taking the wiper and cowl off, you could go ahead and run them with the idea that you’re going to check them after 20k miles. It’s not like they’re going to damage the engine. But my educated guess is that those are not legit. Based solely on the fact that the box says “Made in Japan” and the bag says “Made in China”. That just makes no sense. I presume they shipped from China?
Please, please explain to me why the box says made in Japan, and the bag they come in says made in China? I would NOT install those plugs in my car. As mentioned previously, they're missing the ground electrode tip. Without that tip, they will wear extremely fast (compared to plugs with the ground tip), the gap will be larger and you'll start having misfires. Do it right, one time, so it doesn't look like this: 2005 Spark Plug replacement....... | PriusChat
Thanks for all the inputs guys, over the long weekend I did the intake manifold and EGR cooler cleanings and I went ahead and installed the suspect Denso's since I had the cowl off already for the other bigger jobs. All seems fine for the first 150 miles or so. I'll run them a while and plan on swapping them for some more authentic ones in the near future after I gather some data on the behavior with the hotter heat range.
I do, which is why I said behavior rather than performance. I’m hoping that maybe I can see something that Toyota saw before they recommended the change from the 20 to the 16. Based on what I saw this weekend I’m really hoping to decrease the hard carbon fouling of the intake ports. I doubt the plugs will do it but a guy can dream.
The heat range of the plug refers ONLY to the temperature of the electrodes and the nearby attached parts of the plug itself. It should have absolutely NO impact on the temperature of anything else.
Not to be pedantic but that’s a picture of a different series of denso plugs. That’s an ixeh20tt, twin iridium tips, which I would have tried to get for my car but they don’t make it in a 16 heat range. The standard sc20hr11 and sc16hr11 only have a plain platinum ground as far as I’m aware.
https://www.denso-am.eu/media/corporate-news/2017/june-2017-product-bulletin-supersessions-within-the-spark-plug-range/
Take a look at this....plenty of clues in this that lead one to believe there's probably a lot of Chinese copies out there. Iridium spark plug , Toyota Spark Plugs DENSO SC20HR11 OE 90919-01253 For Toyota length 26.5 mm
