How to Determine the Material of a Spark Plug?

[RichardMarie]

Distinguishing the material of a spark plug is done by examining the central core of the electrode. The specific method is as follows: a thicker core indicates a standard type; a thinner, white-colored core indicates platinum; and a thinner, yellow-colored core indicates iridium. What are the types of spark plugs: The main types of spark plugs include: standard spark plugs, projected insulator spark plugs, electrode spark plugs, seat spark plugs, pole spark plugs, and surface gap spark plugs. How does a spark plug work: Working principle of a spark plug: The ground electrode of the spark plug is connected to the metal shell, which is threaded into the engine block via the cylinder head. The insulator primarily serves to isolate the metal shell from the central electrode. The terminal nut is the part of the spark plug that contacts the high-voltage coil. When current passes through the terminal nut and the central electrode, it ionizes the medium between the central electrode and the ground electrode, generating a spark that ignites the air-fuel mixture in the cylinder.

[VonPiper]

Back when I drove an old van, figuring out spark plug material was all about experience. Copper plugs were cheap, but after about 10,000 kilometers, the electrodes would turn pitch black, and you'd feel more vibration during acceleration. Platinum ones were much better – the electrodes stayed shiny silver, lasting at least 40,000 kilometers with smoother acceleration. For a quick check, just pull one out and look at the center electrode thickness: copper plugs have thick electrodes, while premium materials like iridium have needle-thin ones. Price tags also tell the story – budget cars use copper, while luxury models often come with platinum or iridium. Over time, inferior materials directly increase fuel consumption. I once had an engine burn out due to material issues, so now I always pay attention to this detail during maintenance.

[LaJake]

As someone who frequently repairs their own car, the best way to judge spark plug material is from a practical perspective. The most intuitive method is to observe the electrode color: copper electrodes tend to be reddish or copper-brown and will oxidize and turn black with prolonged use; platinum electrodes remain bright white, resist rusting, and last more than twice as long. When removing spark plugs, use a magnifying glass to examine the electrode shape—copper cores are generally rounder and larger, while high-end ones are slender and heat-resistant. The packaging will indicate the material code, such as IRC for iridium-copper core and LDR for platinum single iridium. The price difference is significant, with copper plugs costing tens of yuan and premium metal ones often priced in the hundreds. Choosing the wrong material can lead to ignition failure or engine knocking, so it's advisable to record the material type when replacing spark plugs regularly.

[MacMolly]

When replacing spark plugs myself, I prefer simple methods to confirm the material. The packaging or manual always states the material type: 'copper' means copper, 'platinum' indicates platinum, and so on. After removing the old ones, observe the electrode's color and thickness: copper ones tend to rust and turn black, with thicker electrodes; platinum or iridium ones have smooth, shiny white surfaces with slender, durable electrodes. Searching the spark plug model online will provide a list of parameters that directly tell you. Material affects service life—copper ones need replacement every 20,000 to 30,000 kilometers, while premium ones can last over 40,000 to 50,000 kilometers without issues. Ensure they match the vehicle's original requirements to avoid affecting ignition efficiency.

[DiOlivia]

Spark plug material directly affects durability and cost. Copper plugs are inexpensive but short-lived, requiring replacement every 30,000-40,000 km. Platinum and iridium plugs cost twice as much but last 70,000-80,000 km. From driving experience, inferior copper plugs struggle with cold starts and cause noticeable throttle hesitation, especially during hill climbs or overtaking. Different electrode heat resistance shows copper plugs with severe erosion marks while premium ones remain cleaner. Check the packaging code or brand logo (e.g., NGK's specific series denote materials). Choosing the right material can improve fuel efficiency by approximately 10%—never compromise performance for cost savings.