Owner reviews for spark plug

My personal experience is that NGK brand for any type of spark plug is superior to others in all vehicles. I use the NGK iridium plugs in my Rabbit and my Honda cars. My older Miata had a wasted spark system and required a change interval of 30K miles, regardless of the plug, so I used the NGK copper plugs in it and there was no difference in performance at all.

I've been running the oem ngk's with the is38 and have never had an issue. They are gapped a little tighter per APR's recommendation but that's about it.

So new Bosch plugs and red-top coils seemed worth the $109. Old spark plugs were pretty crusty, which made me feel better about doing it.

Ended up getting NGK.

I did the plugs around the same mileage in my 2014 CX-5 (2.5 liter), last April at 65,000 miles. Used the comparable NGK Laser Iridium plugs. Mine had some carbon buildup but all in all, they probably could have went longer.

FWIW, if you don't have Bosch, BERU, Bremi, or NGK plugs/coils and have store brand stuff, I stop diagnostic work until you get OE grade stuff put in there. BMW's don't like the Zone/ebay for ignition parts in my experience.

Since then I have take good care of it, replaced the brakes on schedule in August 2020 and then in August 2021 new spark plugs.

Took original plugs out at 50K miles. Not awful but electrode partially rounded with increased gaps. Stock plugs are Bosch and apparently copper core, so I replaced with same. Recommended gap is 0.043'' Added anti-sieze to threads for easier removal next time.

Ive used bosch irridium plugs as replacement for the original denso ones in my GFs 2015 yaris and the car started to have misfires (noticable shuddering) within a couple of weeks. The bosch part is listed as compatible with the OE number, but issues nonetheless. I'm currently going through the warranty process and definately wont be using anything other than the direct denso replacement.

If these are for a TJ (97-05) return them and get NTK (NGK). The 4.0 will not like anything else.