Spark plug Denso or OEM Mazda

The spark plug on the right is 10000% original because it's still working even though it's over 5 years old and has more than 87,000 km on it. The new ones show a little over 5 kilo-ohms, which matches Denso's specification. The old ones show a bit over 3.5 kilo-ohms due to wear.

NGK/Denso are good plugs for my car I used IK20 Denso plugs as they are iridium plugs which is what you want as they last much longer and are better quality

I've been running Denso Iridium on 7 Saabs for years.. both 9.3 V6 and 9.5 2.3l... never an issue on any after 100s of thousand of miles.

Eqt recommends NGK 4905 or Denso 5749. I personally run the densos and they have been good so far, they spark ????????‍♂️.

I'd opt for a set of 1 step colder plugs. Ideally non projected tip like [Denso 5749](https://www.fcpeuro.com/products/vw-spark-plug-denso-5749) or [NGK 4905](https://www.fcpeuro.com/products/vw-spark-plug-ngk-r74388). Though these are costly.

Hondas are notoriously picky about the plugs being Denso.

I’ve used denso IK20TT in whiteblocks and they work very well, may need to re gap if you have some boost raising shenanigans going on

Denso or ngk. Bosch at worst. I would recommend against the off brand in your photo.

I tried Denso once. I took Denso’s out and replaced them with Denso’s. They ran for 500 miles and quit.

Im running denso step 2 cold plugs from bms website and tbh i regret not going with the hks plugs