NGK Spark Plug, NGK Iridium IX, 14 mm Thread, 0.984 in Reach, Tapered Seat, Stock Number 6509, Resistor, Each

Have about 5,000 miles on them, so far completely uneventful. I replaced the stock platinum plugs with these after the engine started stuttering badly on steeper inclines around our house. Its apparent immediately that the car is much happier using these than what was in it to begin with. Didn't seem to increase gas mileage (I'd hoped they would) but running better is sure to be better for the life of the engine.

I put these in my 2012 Chevy Camaro V6. Install was a breeze and I could definitely tell the difference in engine idle, throttle response and power when driving. I would recommend to anyone who's looking to upgrade.

Put in my Roush, all good

So far so good. They came gapped to about .042 ish. Adjusted to .035 for my 2012 f150 ecoboost and it runs like new! Old plugs were the expected .045 and just ran a little off... Put 500 miles on the new plugs and they work great! Will update if anything changes.

I was getting poor fuel economy in my new truck. Tried high flow air filter which helped a little (1.5 mpg) but these plugs kicked me up to 18 mpg. Very happy with the performance. We will see how long they last but I have high expectations.

Great replacement and it's the same as motorcraft but you're not paying for it to be put in a ford box.

Great plug. Installed with no issues on my F150 each one had the perfect gap.

Took less than 30 minutes to change all 8 in my coyote and made a huge difference in drivability over the motorcraft iridium OEM plugs. Will be my next choice when I need to replace again.

These spark plugs are rated form 80000 to 100000 km. The identical ,double the price, Laser Iridium LTR6B19 plugs have an additional platinum lower electrode to extend the max mileage to 160000 km. .

Very good quality