7397 TR5IX Iridium IX Spark Plug, Pack of 4

This is a review for : NGK (7397-4PK) TR5IX Iridium IX Spark Plug, (Box of 4) I installed these today to replace the original factory AC Delco platinum plugs that have 164K miles on them. This is for a 2005 Chevy Silverado 5.3L. The plugs fit and were easy enough to install. I did check the gap to be sure they were all 0.40. Not one was missing or broken. I applied the anti seize lubricant. I then hand tightened using this: GearWrench 80546 5/8-Inch x 6-Inch Swivel Spark Plug Socket Actually used it to remove the old plugs too. I used a torque wrench to 10 foot-pounds (range is 7-14.5 foot pounds for these). I used some Taylor wires which look nice the the jury is out due to fit and degree of difficulty to get those on. Time will tell if these will last. Since my factory plugs were still running fine with absolutely no carbon build up (no need to soak in PB Blaster as I had feared), it was really easy to get those off. The truck idled nicely then and about the same with these. The real test will be in two weeks when I drag my 6000 pound travel trailer out of storage and go camping. If anything changes for the worse, I'll update. If these continue to run fine, then I won't. NGK packages these in the individual boxes and all four into bigger box. But a nice touch is a small cardboard tube going over the threads to protect them from possible damage in shipping. Never seen that before. nice.

Good NGK product, great for Chevy trucks. These would cost almost double what I paid had I bought them at a parts store.

Bought them for my 2005 Camry, works great, price was good and it shipped in time.

Mira muy buen producto el problema fue el que la trajo por que me las trajo echa Lata 1 de Las 4 venia echa mais eso nomas de ahi todo bien vale

Good quality but needed to be gapped.

Confirmed these are the newest spec for flex fuel engines, there are at least 2 TSBs tightening the plug gap and electrode type for the flex fuel engine of this vintage. One of the plugs removed from the donor engine had a cracked porcelain insulator in two places, the length of the plug, likely causing a misfire condition. Do not try to adjust the plug gap on an Iridium plug, the should be factory set, confirm the advertised plug gap matches the latest TSB for your application.

These came properly pre-gapped for my 2002 Yukon 6.0L, and I did check them all. Massive improvement in reducing misfires.

Doesn’t fit my car wrong part

Found the ones I needed on Amazon at a decent price. Brand is highly recommended. Don't know how much overall performance improvement I'm getting but it's good to know I have one of the best plugs available. They were installed in a 2010 Ford Escape with leaky valve cover gaskets. Replaced the gaskets and I should have peace of mind for many years. Free delivery definitely made a difference in buying from Amazon rather than from other on-line sellers.

All 8 were at .035-.037. Adjusted to .04 and runs great with new wires and coils

I heard about NGK spark plugs fakes being sold on Amazon but these are the real thing.

Un super produit NGK qualité japon... Les bougies iridium sont les seules modèles conçues pour un kilométrage élevé, avec une consommation réduite.

Perfect gap engine runs like new a BIG improvement on gas mileage.