Spark plug Bosch or OEM Mazda

I used Bosch iridium spark plugs in my 2018, no issues

I've had my Bosch platinum spark plugs in for 120k+ kilometers and they still run as good as they did the day I installed them, back in 2011.

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.

Just got a Jetta again - 2010 Limited Edition just shy of 100K miles and I've got one problem with it. From a cold start, usually in the morning, the 1st 10-15 seconds run rough before settling down to idle.

I have never seen any real large difference in NGK, Denso, and Champion if the proper heat range/type plug was used.

I'm not a fan of the old platinum Bosch design or regular autolite.

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.

I've heard for many decades how bad Bosch spark plugs are and I figured the coils would be just as bad, if not worse.

Bosch spark plugs are junk.