Spark plug Bosch or Denso

I had good luck with ngk bp6hs, Bosch w8Bc, champion l87yc and renault oem short thread (yes, really.) plugs. Bosch w8ac used to be good but i had some arrive not working out of the box recently so I'm now avoiding them.

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

the spark plug is less than 10k km old (bosch) so I initially did not change it. Decided to change it anyway to original mercedes (turns out made my NGK) bam emission passed, LTFT now hovers at 5-8%.

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.

Bought mine from rock auto; got the Bosch ones since the NGK’s are really only recommended if your car is tuned

Bosch spark plugs aren't bad, per se, but they're not really anything special.

I tried Denso once and didn't have great luck with them.

Never use the Bosch ones for the E46s. Just not working right

I tried one of the economy plugs on my 02 Accord. Ended up having to chuck it and buy a Denso.