Spark plug Denso or OEM Mazda

if you want some good plugs, get some denso IKH24, they are 1 step cooler than stock plugs.. I change mine out every 20k miles..

IKH 24 plugs with stock coils work just fine. No cutout, rough idle or misfire.

Replaced stock with denso ihk24.

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

denso ik22 works also, also an iridium tipped plug

I bought a box of denso.

Everyone has been praising (fleet vehicles).

I'm pretty sure that modern Mazda's do do this, only not in the situation you're describing. They use it for their stop start system to save having to fit a beefier starter motor and what not, simply inject an extra dose of fuel and fire the spark plug to get the engine going again.

Im with the Densos already and the spool and throttle response is so much better. Even with gap 0.075mm they are much better.

Just an update for you and a PSA: CHECK YOUR SPARK PLUG GAP ON NEW PLUGS. I too trusted that the iridium plugs that I just bought should've been pre-gapped, but I noticed immediately after a tune-up my gas mileage went to piss. Popped the plugs back out and sure enough each one was well over 1mm .

I installed brand new denso ik24 plugs gapped at .026 and I am still getting misfires.