Spark plug Bosch or AC DELCO

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.

I have only used Bosch plugs in my cars, and I have not had any issues with them yet.

The Neuspeed chips don't perform well at all, and the 2.0's do best with BOSCH FR8DS's.

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.

Champion is OEM and what we suggest at work, but NGK has never failed us with any application. Bosch is generally terrible and we only use them if it’s a very specific application.

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...