NGK (7164) TR55IX Iridium IX Spark Plug, Pack of 1

great product,works well, good price.

I was not aware that this model of NGK Iridium plugs is only Iridium on the tip and not on the ground electrode. And I didn't know when I bought it that would matter. My 2001 Grand AM V6 3400 engine uses GM's Waste Spark system. Which is a dual firing ignition so the 2nd spark burns excess fuel for better efficiency. Other brands and models have similar systems. When the 2nd spark ignites from the opposite direction which causes wear to the ground electrode. Which means this plug will work, but the poor 2nd spark can cause very minor idle inconsistencies that you likely won't notice unless you know what to listen for. But overall it will wear out the plugs much faster which defeats the point of Iridium in the first place. So if you have a dual firing spark system, spend the money and get either Double Platinums or Double Iridium plugs. I ended up getting the OEM AC Delco Pro plugs for my Grand Am which are a Double Platinum 100,000 mile plug. And those work great in my car. Unfortunately I can't return plugs I installed. lol. So make sure you know if you are ok with only the tip being Iridium or if you need both the tip and ground to be the same coating. The listing on Amazon and even at NGK was not very upfront with mentioning that not the whole coating is Iridium. Which is what I thought I was getting. I am sure these are 5/5 star plugs for single spark systems.UPDATE: I have updated my review to reflect that these are great plugs for single spark systems. But I did not end up keeping them for my dual spark waste system Grand Am. Make sure to use plugs that say "Double" in the name so you know both electrodes are the same coating if you have a Waste Spark system. I want back to the Double Platinum's that match the OEM for my Grand Am.

Made a great difference in my car

plugs working fine--I was nervous installing since these went on a 3.1 chevy v6--hard as the dickens to get to the back cylinders, and the plug holes are waaay down in there. used anti-seize lube on the threads--although I imagine this is the last set I will put in. after installing along with new wires I discovered that the off-idle stumble was being caused by the 1-4 ignition coil. replaced that, and the little v6 is running exceptionally well. also had a vacuum leak on the weird tube that runs from the pcv on the front valve cover--then to the top of the intake to pick up vacuum (a plastic fitting that had deteriorated) and then over to behind the intake where it hooks up with some unknown port--I couldn't see it but I put new rubber hose where I could, used a standard t fitting on top to go in the intake (along with an ill-fitting grommet) then smothered it with rvt. working fine now, but you can tell I did it myself.Can't say enough good thinks about NGK--first used their plugs back in 1977 on my KH400 Kawasaki Triple--great product!

I have used these for years on GM LT-1 and LS1 engines with great results. The LS1 has always been stock. I am at 195K miles right now and have usually changed the plugs at about 60K. I tried going to 80K once and did notice that the car was a bit more sluggish before I replaced them. Replacing the plugs at 60K has worked great for me. On the LT-1 engine, I used the TR55IX plugs until I bored, stroked, and supercharged it. Then I used the TR7IX plug which worked great for that application. I feel these plugs offer good performance over a long service life at a reasonable price. I have not been impressed with the performance of double platinum and laser plugs that I have tried. They all seem to foul up well in advance of their advertised service intervals.

Replaced the original platinum spark plugs that had around 60k miles on them. I just wanted to have my car tuned up so it would be in peak performance / reliability since I would be driving longer distances than I usually do.These did the trick. The car felt more responsive, idles better, has a bit better acceleration now, and I also changed out the wires when I had these installed.I love these spark plugs so far. My car runs better and since the tune up of a new air filter, sparks, fuel filter, I get better MPG.Just need to take care of your car and at least I don't need to worry about replacing the spark plugs on my car probably ever again, but this 1999 Olds is still going strong and only has 75-76k miles on it. Treating it well and keeping it maintained, still very reliable.

These are plugs forged by ninjas in the deep bamboo forest of Japan, and yes, they made them for my 2001 mustang GT. My car runs so much smoother than before (with stock 40k mileage ford plugs) now I can be the Street Assassin at Wild Horse Pass Raceway (aka Firebird Raceway, AZ). All joking aside they smoothed out my idle on a the tuner (TPS Absolute value .164 and smooth) Plus they are made in Japan, what's not to love there?

These where half the price you would pay at the Auto parts store. Picture shows a crush gasket on the plug, but it does NOT require one.The NGK plugs are a tapered thread, so when you tighten it, it seals.

6 months ago solved misfire cyl 2

Läuft in meinem Volvo Penta 4.3 GXi wunderbar! Warum sich der Preis nach meinem Kauf innerhalb eines Tages mehr als verdoppelt (!!) hat, bleibt mir ein Rätsel...

Wollte was gutes für meinen 15 Jahre alten Chevy V8 gönnen und mich für die Kerzen entschieden. Nach dem Einbau den Motor angeworfen und sofort den ruhigen Leerlauf bemerkt. nach ein paar Wochen stellte ich einen reduzierten Verbrauch und deutlich besseren Durchzug fest. Also absolute Kaufempfehlung!!!