Spark plug Bosch or BERU

the original spark plugs died (delphi) so i changed them for Bosch ones

We used to put Bosch W7DTC spark plugs in them. No gapping required, smoother idle, and they last 60k miles, maybe more.

You can get NGK or Bosch plugs on rockauto for around $10. Not sure which was OEM, some like NGK for Mercedes in general but Bosch tends to be the OEM maker of plugs for MB.

I recently changed my spark plugs on 2012 Ford Focus. I used Bosch and got a 3 MPG boost.

Since I mounted Bosch 4-prong spark plugs, fuel economy has improved a lot. Gone from 12-13 km/l to nearly 15 km/l.

Also, some engines get particular about plugs. Bosch has a bad rep for the 3400 engine in my Grand Am, while NGK and AC Delco(I've got NGK Iridium IXs in there now) are fine.

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.

Although I prefer Bosch sensors over other brands in certain parts of my Mk 5 2.5, I will not buy Bosch spark plugs. Many professional mechanics over the last 3 decades have told me horror stories about them.

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.