Spark plug NGK or Motorcraft

As long as you use the right type and gapped correctly, then you are fine. NGK, Autolite, Motorcraft, bosch, all are fine.

I have been running them for 50,000 miles with is20 then is38 setup. Work perfect.

I just ordered new spark plugs and an oil filter as well.

I just did the change myself on my Gen 1 Mazda 3. It's simple! I used NGK Laser Iridiums.

The NGK's worked beautifuly.

I used NGK, 6 month no issues.

Get NGK plugs instead...mine have been working great.

I'm currently is20 United 91 octane tune, APR packs and NGK RS7 plugs (one step colder thant oem), gapped at around 0,028'' and car feels solid. No misfire, no EPC. However it honestly feels just like when I was with oem coilpacks and plugs. Maybe now idle feels a little bit smoother.

NGK literally welded a platinum bar to the ground electrode. Is it going to be really butt dyno noticeable? Probably not. But at least it should last at least twice as long as the BKR7E-IX, since I've noticed after 20,000 miles, my mpg goes to crap. The projected square platinum electrode means wear resistance on the ground electrode, like the factory laser platinum spark plugs (PFR7S8EG) having a platinum wear disc on the ground electrode.

Went through both ngk and autolite, didnt like they're spec'd plug for it.