Spark plug NGK or OEM Mazda

I use iridium’s NGK haven’t had any issues.

Just replaced my previously purchased NGK Iridium from Rockauto.com After 100k miles the looked like I put them in yesterday.

NGK Laser Iridium is the Honda spec and what I buy and have had no issues for 5x 105k intervals.

I read that NGK plugs already have a coating on them, so I didn't apply any when I fitted new NGK BKR6EQUP plugs. Torqued them to 25Nm.

The old ones (also NGK) came out easily and I used a bit of tubing to hold the plug as I installed it into the thread, making sure it was threaded on straight before switching to a ratchet and torque wrench to screw down and tighten.

Every one of my internal combustion engines (3 cars, 2 motorcycles, zero turn mower, has NGK plugs.

It's hard to go wrong with NGK spark plugs on Japanese vehicles. That's what I've always done with great luck.

I'd recommend getting either spark plug yourself at a parts store, they last much longer than platinum spark plugs and offer more performance. plus the rutheniums, if available for your model year, offer slightly better fuel economy as well. if you want the ones with the longest longevity and best performance I'd get iridium high ignitability, but those can be costly. definitely go with NGK. bosch are also decent and denso are usually oem but I personally prefer ngk.

the cheap, no name one it came with was doing the exact same thing as the new NGK one I put in (and properly gapped) to try and remedy the issue.

I replaced the spark plugs with NGK Iridium IX factory gapped to .044". Everything went smoothly, reinstalled coils, air box, battery, connected MAF, and started the car. Now it is shaking, smoke coming out the exhaust, and blinking check engine light.

2018 Kia Soul Base, 57k miles, on the third set of plugs and they are misfiring already. Factory plugs lasted 30k miles, followed up with Autolite plugs lasting 10k (which I chalked up to being cheap/low-quality plugs), but now these NGK iridiums are giving out with 17k miles on them.