How To Spot Fake Denso Iridium Power Spark Plugs 2017

How To Spot Fake Denso Iridium Power Spark Plugs 2017

Err But They Look Identical I Hear You Say?

Just when we thought the counterfeit NGK Spark Plugs we found recently was a pretty close match to the real thing, we’ve now found counterfeit Denso Iridium Power Spark Plugs as well. Every detail has been cloned to the closest result possible, except for one major flaw; these plugs don’t actually feature any Iridium in the centre electrode at all!

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Alarm Bells

  • Alarm Bell 1: No laser-welded Iridium tip, features a machined down nickel alloy tip instead.
  • Alarm Bell 2: Low-resolution, scanned copy of the box.
  • Alarm bell 3: EAN of the 4pc outer plug box is stamped onto the 1pc inner boxes. This should be a different EAN number.


Unfortunately, we can’t rely on the packaging as a 100% counterfeit measure. This is because Denso has factories all over the world and undoubtedly each facility will use a different machine for all aspects of the packaging. However, what we can do is look out for clear blooper signs. For example the fakes we discovered had the 4pc EAN number as printed on the outer box, printed onto the 1pc inner boxers too. This kind of mistake would be impossible with Denso’s manufacturing quality control and would mean they’d have no stock figures on 1pc boxes. You can also see the printing sharpness is a lot less in the photo.

denso4 Copy

It seems like a high-quality scanner has been used, however it’s in no league with a print job that’s fresh from an original artwork file.

denso11 Copy

Below: On the 1x boxes, the font is different and the part number is followed by a #4 which indicates 4 pieces. Except, it’s a 1x plug box, right? (another blooper)

denso6 Copy

Below: The cardboard material used is a cheaper type on the fake box. Also look at the corrugated fold lines too, they have different patterns.

denso2 Copy

Below: Subtle differences again, printing sharpness, also notice that the curved edge on the thumb flap is a different shape.

denso7 Copy

Below: Printing sharpness

denso13 Copy
denso12 Copy
denso5 Copy

The Plug

This is where it gets hard to tell them apart. There’s no doubting that these are high quality copies, however to trained eyes and with genuine Denso’s on hand from our stock, the differences are fairly obvious.

Two Below Pics: The centre electrode tip definitely don’t feature a laser welded iridium tip, they appear to be made of a nickel alloy instead which has been machined down.

denso10 Copy
densotip1 Copy

Below Pic: The crush washer is almost identical, however by looking at the centre recess you’ll notice the genuine Denso has a much deeper groove between the top and bottom rings. The metal areas around the punch letter stamping appear more swollen than the real plug also.

denso9 Copy

Below Pic: Font style on the part number is very authentic looking, this is a clear sign of tracing paper being used and then transferred to Photoshop for touch up.

denso8 Copy

Update: August 2018

During the last month or so, Denso has gradually started phasing in a new Iridium Power packaging design. The boxes below are 100% genuine, directly from Denso.


Please share this article as much as possible to make others beware. You can purchase genuine Denso spark plugs from our online shop. We’re a UK based company however we can provide worldwide shipping.