NGK Iridium Laser SILZKGR8B8S Spark Plug Specifications Whatever your use or engine set-up the correct choice of spark plug is very important. Iridium is very heavy and dense metal ensuring that NGK spark plugs have a longer lifespan than OEM ones withstanding more than 100.000 km in standard use Compatible with Non-exhaustive list. Toyota Supra A90 BMW 140i B58 BMW 240i B58 BMW 340i B58 BMW 440i B58 Mini Cooper S F56