Spark plug Bosch or Champion

Bosch iridiums, these for longevity, copper ones have better spark if your concern is performance

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 ended up leaving them as is and the car seems to be working fine.

i might switch out the plugs again because my buddy got me some freebie bosch plat 4 and i wanna put the bosch single silvers in.

Warning about Bosch spark plugs!!! The piece of ceramic around the electrode failed. These were in a 2018 sonata turbo for about 10k miles. Thank God it didn't fall in...

Ive used bosch irridium plugs as replacement for the original denso ones in my GFs 2015 yaris and the car started to have misfires (noticable shuddering) within a couple of weeks. The bosch part is listed as compatible with the OE number, but issues nonetheless. I'm currently going through the warranty process and definately wont be using anything other than the direct denso replacement.

Yeah I own and operate an auto repair facility and refuse to use Bosch plugs because I’ve had a lot of issues with them in the past. Misfires mostly.