Spark plug Bosch or OEM Volkswagen

I had a 2012 Passat I drove for 10 years (after buying used with ~20K miles) and only just replaced two weeks ago with ~125k miles. I had to replace the alternator at one point and some other general stuff like spark plugs over the years, but that was it really. Nothing super expensive.

Today I installed new spark plugs and the misfiring situation has improved significantly but is not completely gone. If I pull up the RPM too quickly the misfire counter goes up.

I just replaced my oem densos with some Bosch plugs that were labelled as being pregapped 1.1mm. I wanted them to be 1mm and checked with a gauge and Lo and behold they were already at 1mm. Whacked them in and improved my fuel consumption immediately.

I took it back in after setting the DPR to 2.5± 2.5 mA, checking again for any vacuum leaks, tightening down all the exhaust components, and changing out the spark plugs (again). I also checked the O2 sensor, it was fluctuating between .1v-.7v continuously.

To be honest the last plug VW went with , the 101905601F (OEM clones Bosch copper nickel FR7HE02 Or NGK ZFR6T-11G (5960) Copper Nickel, Beru BRU-Z272 copper nickel ) for the 2.5 is best. It’s one shade cooler and will have less spark knock. You have more timing.

I got misfires with FD5POR RS2 plugs. Almost 10000kms on Bosch f2cs this year. Been working perfect for me

I'm running a Blue coil (only because the blue is cool), a compufire, and bosch plugs and wires. The blue coil is juat something to look at. You really wont notice a difference.

This is why I don't use Bosch plugs. It goes back to the quad fire plugs with a platinum center electrode that would fall out.

Long story short: changed spark plugs 4000km ago as per my 2019 Hyundai Kona 1.6t manual. Followed Service manual, and the recommended torque on the side of the box of the Bosch (non OEM) replacement, 17 ftlbs.

Grounding electrode on plug #3 failed, destroying 2 valves and marking up the cylinder wall.

I have the same problem with my recently acquired 2011 Sharan. Tried a suggestion of new spark plugs with no success.