Spark plug Bosch or NGK

OE plugs for this engine is NGK Laser Iridium. Hyundai/Kia usually use either Denso or NGK plugs.

I'd get OEM wires and NGK iridium OEM speck plugs.

I ended up finding a post where somebody was having a similar problem that I was and one of the top comments on that post a guy had said word for word "I hope you don't have Bosch Platinum plugs in there." I ordered NGK ZFR5N copper plugs. I just received them this morning and got work. Gapped them to 0.035. Put them in. Done. Misfire gone. Runs perfect idles like butter.

Went with the fancy ngk plugs. A man of culture. I put those in my Volvo and they say it's heresy.

at 100k km, I replaced (all Bosch) Plugs , Coils, starter, battery, voltage regulator (40).

I've use NGK products in American, Japanese and German vehicles for over 30 years with absolutely no problems at all. Note that NGK spark plugs come with a proprietary anti-seize coating on the threads, so no extra anti-seize is necessary at all.

I’m running NGK racing plugs # 4654 or R7437-9 no issues.

Took original plugs out at 50K miles. Not awful but electrode partially rounded with increased gaps. Stock plugs are Bosch and apparently copper core, so I replaced with same. Recommended gap is 0.043'' Added anti-sieze to threads for easier removal next time.

I put in NGK PFR7S8EG plugs and man the car ran like absolute CRAP when it was cold. It ran fine, even great when it warmed up but it was so bad when cold that it was virtually un-driveable especially under moderate or hard throttle. I ended up putting the old plugs (Bosch platinum/iridium) back in because it was so bad.

Lesson learned: DO NOT EVER EVER EVER USE BOSCH PLATINUM (STANDARD TIP) SPARK PLUGS IN YOUR VR6 ENGINE.... THEY JUST DON'T WORK!