These are fitted to all GTT conversions. Although expensive for us to purchase they do provide the last word in sparkplug performance, and are vastly superior to the std. ‘4 earth electrode’ items, improving both performance and economy.
The Iridium tip and outer electrode ( Hence double Iridium), not only has a much higher melting point than any other sparkplug tip material, but is considerably harder at the same time. This gives very good service life. In most cases we increase the heat range over standard. This is important in preventing detonation from a glowing plug (an engine killer) under extreme load and temperatures. Incidentally we choose NGK over Denso purely due to even longer life.
Articles: CHEAP NGK SPARK PLUGS OF THE WRONG HEAT RANGE CAUSE PROBLEMS!
For: Gen 1 Cooper S (also JCW / GP1)
£49.95+vat (set of 4)