Iridium Plugs

[Fifty150hs]

Originally Posted by StephenVA

Now that I looked at these plugs on a larger screen, I can tell you they are NOT IRIDIUM NGK plugs. Take a peek at the center electrode diameter, it has to be 2x the correct dia size. By the way those little silver spots appear to be piston material from octane pinging (KNOCK) where combustion temps exceed 1200 degree F. NOTE: Aluminum melts at 1200 degrees. (See chart below) Cheap gas w/ poor blends (see Calif regs for details as you all get crap mixes to satisfy CA Research Board) results in really poor combustion consistencies tank over tank.

Call NGK direct to confirm with tech specialist who will have you read off the shell numbers and he can confirm manufacturing batch numbers.

Anything that has volume and profit attracts knockoff suppliers. Copying packaging is easier now than ever with high speed color scanner/printers. Welcome to technology. It happens on anything electronic, medical, and most consumer products. Happened in the fastener world where they flooded all SAE/Fractional grade 8/8+ bolts with similar marking on grade 4/6 bolts. Rotary craft started to fall out of the sky with blades missing as they sheared off. 80% of the US inventory was junk from offshore, heads were marked as if it was produced in the USA.

Aluminum 1220F
Aluminum Alloy 865 - 1240F

Thank you for the info. already ordered new Iridium plugs from Rockauto. Assume they'll be genuine. Doesn't the ECM adjust for knock to prevent it? I've been running nothing but premium, so signs of knocking are surprising.