I think we should consider an Ultimate Spark Plug thread.
What is up with all the new Bosch plugs? Our host has listed Bosch W-3-CSRacing), Bosch F-4-CS (Racing), Bosch XR-2-CS (7700), Bosch WR-7-DC+ (7900), Bosch W-7-DSR, Bosch WR-7-DC+ (7900), W-4-CS (Racing) all listed for a Carrera. There is no mention of Copper or Platinum for these in our host's catalog.
Plus there is a Bosch W-3-DPO for older? cars. Equivalent to NGK BP8ES?
Is there a decoder somewhere? Obviously the number is the heat range and R would be resistor, but how do you tell if it is a platinum, iridium, copper or what ever?