Bests & Worsts Reviews from Amazon

These spark plugs are not genuine NGK iridium spark plugs. I became suspicious when the country of manufacture was listed as Japan, when in fact this particular plug is assembled in the US. I called customer service at NGK here in the US and spoke with a lady, who asked for the 4 digit number on the hex. The number on this set of plugs is not a valid number and I was advised to not install these plugs in my car. It's been over a year since I ordered these, but I usually keep an extra set for each car so they are here when I decide to change them. There are several other telltale signs that these are counterfeit and I'm not putting these in my Prius. I'm shocked that this got past me. but I didn't expect a problem like this on Amazon until I was warned. I still think this seller should give me an immediate refund or exchange these knock-off plugs for what I paid for in the first place. I need to see what can be done about this, and I don't intend to allow this to happen without a response. See pics: There is no concave dimple at the top of the plug. Has wrong country of origin stenciled on ring below hex. Hex has invalid (and difficult to see) 4-digit code, which can be seen in this photo if enlarged. Grounding electrode has sudden bend, rather the graceful "C" shape and the insulator exposes the "iridiun" tip too much, when compared to the genuine plug. The washer is not tapered and can be installed either side up, whereas the genuine washer is distinctly tapered, with the small side towards the engine side. Update 8-2020: The seller of the above plugs (Part Sales) took decisive steps to remedy the situation when informed of the situation. I am happy to add this addendum with the news that the seller has sent me a set of genuine NGK plugs to replace the counterfeit items as described above. The replacements are of exquisite quality and represent the best of the best when compared to others. I don't think this seller intended for the fake plugs to be available at their storefront, and I walk away from this a satisfied customer. The seller gets 5 stars.