NGK Iridium IX Spark Plugs (BKR8EIX x 4). Colder Plug for Models Listed. Colder Heat Range 8 Spark Plugs. Set of 4. In short, select one heat range colder for every 75-100 hp you add, or when you significantly raise compression.
4 x NGK Iridium IX Spark Plugs BKR7EIX11 Colder Heat Range 7 Honda Acura Toyo ++
4 x NGK Iridium IX Spark Plugs BKR7EIX Colder Heat Range 7> B16/B18/SR20/EJ25/FE
4 x NGK Iridium IX Spark Plugs BKR7EIX Colder Heat Range 7 B16/B18/SR20/EJ25/FE
6 x NGK Iridium IX Spark Plugs BKR7EIX Colder Heat Range 7> Modified/Turbo/Tuned
