Spark plug BERU or OEM Mazda

Ive ran Beru ultra copper core for a couple months now and they are one step colder. I honestly dont even check gap on them and my shit runs smooth.

I use only NGK or Beru spark plugs.

I just changed the spark plugs for the first time in like 175, 000 miles

So I decided to I replaced my spark plugs. There was a ton of carbon build up in the first cylinder, and oil on the 2nd, 3rd and 4th spark cylinders, including the spark plugs. It’s running way smoother now but there is still some jerking but it’s not as violent as before.

use beru plugs rather than Bosch, a lot of Bosch plugs sold for this application has the wrong heat range which can cause misfires.

I've been using beru rs7 plugs without any issues.

Yup, these are great. Just be sure you gap them to APR's recommended gap of 0.024" ±0.002" or 0.6mm ±0.05mm. If you want 1 step colder plugs, not needed on your setup, but if you do for the future in Stage 2+. For 10$ more than the OEM NGK you can get the BERU.

Rx-8 in 3years just did maintence and ned sparkplugs 0 problems.

I ran Beru RS7 plus which are one step colder when I tuned stage 1 and they didn't last at all. Might have been under 10,000 miles. Recently went with NGK plus that APR reccomends for stage 2 and so far so good. No misfires since.

I swapped out the oem plugs for Beru rs7 plugs when I went APR stage 2 at ~3k miles. The car ran well. Fast forward to the present with over 18k miles and is20 swap, and I noticed a few stumbles at idle. Nothing major but I figured I'd change them since APR recommends 10-15k mile intervals (visually the Beru plugs looked fine).