Spark plug NGK or Motorcraft

Installed the NGK rs7 plugs and it runs fine. I kept them at factory gap, which was, if I remember correctly approximately .028.

I just hit 40k miles and went with the NGK (RS7) plug gapped to .024, and the RS3 coil pack upgrade. The initial results after install was underwhelming. Car ran a tad smoother, but that's it. Since the benefit of the RS3 packs were to provide a more intense spark, I tried a wider gap ~.028-.030 Man it woke things up! Revs "effortlessly" and pulls hard from top to bottom.

Bottom line: you can't go wrong with NGK. Can't really go wrong with OEM Bosch either but I'd just stick with NGK and make sure you gap them right, call it a day. I'd avoid Denso.

Change the spark plugs too while you are at it, with NGK BKR6EIX plugs (or BKR6E if you want to save money but these are the copper plugs and will not last as long as the iridium BKR6EIX).

changed out some spark plugs, shop here: http://autotech.com/passat/b6-3-6l-2006-2009/3-6l-vr6-ngk-spark-plug.html also I decided to get a new valve cover (comes with new gasket, bolts, bolt o-rings, and of course a new PCV oil separator that are prone to fail)

I used NGK Iridium.

I have a 12 GLI with 82k and just changed my plugs for the first time. Holy cow what a difference. It had been running a little rough and even made it seem like the clutch was slipping on hard acceleration between 3 and 4. I thought it was carbon buildup, but I just had that cleaned up at 60k. The new plugs make it run like new again.

I either use Delco or NGK. Never had a problem with either of them.

I've been pulling my CR8EIX iridium plugs out to check how they are burning a lot recently. I've been seeing some light ash deposits and high speed glazing and the iridium tips of the plugs are not as hot as I would expect them to be, i.e., they are not *white*.

I used the NGK plugs once and kept getting a pretty bad hiccup under hard acceleration.