NGKIridium IX Spark Plug LFR7AIX # 2309 PK4

I have them installed in my 2005 STI. I've ran these One Step Colder plugs for over 15 years on my STI. Just something I've always ran with my custom pro-tune, these are perfect! I was a bit worried with some of the reviews stating these were fake NGK's. However, not the case. The plugs are working, no issues and I verified them to be the real deal.

The NGK Iridium IX Spark Plug is a standout performer in the world of automotive maintenance.The first thing that strikes you is the build quality. These spark plugs exude durability and precision engineering. The use of iridium in the electrode ensures excellent longevity and consistent performance over the long haul. I've found that they easily outlast conventional copper or platinum plugs, making them a cost-effective choice in the long run.Installation is a breeze, thanks to the well-crafted design. The hexagonal nut at the top of the plug simplifies removal and installation, even in tight engine spaces. I appreciate the ease with which these plugs fit into various vehicle models.When it comes to performance, NGK's Iridium IX Spark Plugs shine. They offer excellent ignition efficiency, resulting in smoother idling, improved fuel efficiency, and reduced emissions. I've noticed a noticeable boost in engine responsiveness and power delivery after switching to these plugs. Whether you have a daily driver or a high-performance vehicle, these spark plugs can make a significant difference.One more noteworthy feature is their ability to resist fouling and carbon buildup. I've experienced fewer misfires and less maintenance hassle since using NGK Iridium IX Spark Plugs.While they might come at a slightly higher price point compared to standard spark plugs, the enhanced performance and extended lifespan make them a worthwhile investment. If you're looking to optimize your engine's performance and reliability, these spark plugs are an excellent choice.In summary, NGK Iridium IX Spark Plugs are a top-notch option for automotive enthusiasts and anyone looking to improve their vehicle's performance and longevity. Their quality, ease of installation, and impressive results make them a standout choice in the spark plug market.Will continue to purchase!

1step colder plugs for my 17sti. Definitely feel a difference

Worked great on my e85 trackhawk

No issues with the product, no need to adjust gap item just worked perfectly.

Plugs were all in great condition and made by NGK. Had a high rpm misfire and decided to change plugs early. I like going 2 steps colder and gapping them @.026 for tundra 5.7 with supercharger.

Authentic 1 step colder2010 wrx applicationThey came gapped around .028-.030I run 24lbs boost on Cobb 20g with a .031 gap no spark blow out

For Genesis Coupe owners, I can confirm these fit the 2013 2.0T (despite Amazon saying they don't). These are the same model of 1-step colder spark plugs recommended by tuners BTR and SFR.Some of the gaps varied quite a bit out of their boxes so check with your owner manual or tuner for spark plug gap recommendations. I'm glad I purchased a gap tool with these.I ran these before my tune with catback exhaust, intake, and blow off valve without any issues. However, most tuners and the community agree that these spark plugs are only really needed if you are planning to increase power (via tune or otherwise). I matched them to my stock gap of 0.028" without any issues. The car runs smoother than my older plugs and is running stronger now that I've installed a tune.