Hyundai Sonata / Kia Cerato / Kia Rio Iridium Spark Plug PFR5N-11 18817-11051 High-Efficiency Ignition Upgrade

Hyundai Sonata YF (2000-2006, 2.0L/2.4L), Kia Cerato (1.6L/1.8L) and Rio (1.4L/1.6L) use Iridium spark plug PFR5N-11 / 18817-11051 to improve ignition efficiency and fuel economy. Iridium electrode is high-temperature resistant with a life of 80,000–100,000 km, significantly better than nickel alloy. OEM numbers 18817-11051 and PFR5N-11 for easy cross-reference. Install torque recommended 20-30 N·m; use a torque wrench following factory procedure to avoid thread damage; replacement difficulty is medium.