So, spark plug replacement time for the Mazda (2.3 engine). On the right, standard iridium that are OE on the car. Price is identical, actually the Ruthenium are a few cents cheaper, but that's negligible. Gap is the same, form factor too. I always thought the Laser iridium meant double iridium electrodes, but now that I look closely I can only see one ? Not sure about the replacement interval, but it's a very long thing like 100k Km. Ruthenium seem to have two visible pointy electrodes of whatever fancy metal they are advertised. There is little I can find about Ruthenium spark plugs, except it's the new sliced bread, better, last longer, etc etc. If the Laser iridium have indeed only one iridium (or platinium + iridium) pointy electrode, I can see the Ruthenium lasting longer. So, what's your take ? Can you educate me on spark plugs ? On most 4 cylinder they are real easy to replace so I always them as a maintenance item, replace every few years and don't think twice about it.