Owner reviews for spark plug

They are great. Also around 12k miles on mine - no issues.

Yeah I've had these on my 2010 for about 12k miles now. No issues, have been performing just fine.

Plugs(Denso IK22) coils(DENSO or Hitachi) and a valve adjustment, all due at 100k. They really do make them run better and much more reliably.

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.

Motorcraft is all I use , heard to many stories about aftermarket plugs causing misfires

That’s curious….. if you look closely at the end of the shorter plug you can see another set of threads, it looks like there an insert threaded onto that spark plug. It would appear that it wouldn’t be sitting where it needs to in the combustion chamber so that may explain your misfire.

Bosch spark plugs are also trash.

Autolite plugs are bad.