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I know they put a platinum disc on the ground electrode, not sure how they get the other half of the double platinum, unless they put a thin platinum coating over the iridium centre electrode metal ? Those are Iridium plugs though. It's been a few years since I used them, they may have made some small changes to them. I tend to use the NGK IX Iridiums on my vehicles with the ground centre electrode, no platinum mixed on them.
I like NGK Iridium BKR8EIX. One step colder so good for boost and they make a tangible difference on NA as well. Compared to stock PFR7S I feel more power and engine response. Obviously not a huge difference but you'll know it when you feel it. Very good plugs.
These I bought last summer, via Amazon.
The old plugs were bad so the slight improvement was most likely due to the plugs being new, not being Iridium.
YMMV.
These I bought last summer, via Amazon.
The old plugs were bad so the slight improvement was most likely due to the plugs being new, not being Iridium.
YMMV.
That's correct. The performance improvement from Iridium is that the spark gap is maintained in spec longer than platinum or steel as the miles rack up - less erosion of the electrodes. On all plugs the center electrode erodes with use, as does the ground electrode. Over time the plug gap widens. At 50k miles my factory plugs were out of spec with a gap over 1.3mm as the center electrode had worn down. With an Iridium plug the gap would have been smaller at the same mileage as it would not have eroded as much.
You can get a slight performance improvement over thinner center electrodes and tapered ground electrodes which some iridium plugs offer. A fine wire center electrode and a tapered ground electrode tends to offer the best performance as the spark is better exposed to air/fuel mixture, bigger quench as the spark goes from sharper edge of the center electrode to the sharper edge of the ground electrode.
Last edited by zeroptzero; 12-15-2018 at 01:12 PM.
Note how this one says: "Iridium:Platinum." And the new ones I put into the Element just says "Double Platinum." Wonder if NGK is changing formulation?
12-10-2018, 04:36 PM
NGK Iridium spark plugs
