Are these sparkplugs genuine?

[bonjo]

The ground electrode finish looks very rough and the metal body finish is not smooth. The legend on the insulator is also not crisp.
Denso also have a leaflet on how to spot a fake

 

[slybunda]

The ground electrode finish looks very rough and the metal body finish is not smooth. The legend on the insulator is also not crisp.
Denso also have a leaflet on how to spot a fake

Apparently this is standard for denso made in china

 

[Oldwolf]

Buy them from a Toyota dealer. You may have to pay more, or wait until they go on sale.

 

[Greenbeforeblue]

If a guy was willing to take a chance on some spark plugs being genuine to save a couple bucks; it naturally follows they'd be willing to hole a piston when some part of them breaks off.

 

[JavierH19]

Next thing to ask, should I apply copper grease to the plug threads or not? Since new plugs will be in the aluminium head for a long time wondering what's recommended here

Many of them say not to simply because they don't know how much you'll use and thus how much % to tell you to reduce torque. Yes i'd use copper anti seize on them. A little is enough and reduce torque by 25%. I like to put a tiny bit more than usual and I reduce by 30%. Used ngk laser iridiums last time and that was about 70k miles ago.

 

[slacktide_bitog]

Next thing to ask, should I apply copper grease to the plug threads or not? Since new plugs will be in the aluminium head for a long time wondering what's recommended here

Denso says not to use any anti-seize on the threads. You can install them without it, and they will come out with no problem after 100 miles

 

[slybunda]

Can copper grease be used with aluminium head or does it need to be some sort of aluminium grease due to dissimilar metals?

 

[SeaJay]

They are genuine spark plugs. Who and where they were made by may be unknown.

 

[JeffKeryk]

Next thing to ask, should I apply copper grease to the plug threads or not? Since new plugs will be in the aluminium head for a long time wondering what's recommended here

I use just a wisp of antiseize on the lower threads. Torque to the lower range.
If you got the from a reputable store, they should be fine. From an Amazon store front at at a reduced price, well....

Good luck.

 

[DallasCMT]

Denso makes plugs in China so they are most likely legit, however I'd use this site as a guide.

https://www.driven2automotive.com/s...9qyBFB0rDteT6uMrZ8FJFXoOGiaLhAEP8E1Rz7PcFidWC

Good info... That site has all kinds of other good info, as well.

 

[dfarr67]

Country of origin is unaccaptable to me- for the mileage you get out of plugs these says- spend the money and get oe or something else.