Single V-Groove ground electrode with Yttrium center electrode for longer plug life and expanded flame kernel. (V-groove creates expanded flame kernel which may reduce surging).
Optional hotter heat range for ALL OILHEADS for colder climates or extended low-speed engine RPM; may reduce surging. Hotter heat range than original F6DDC, FR6DTC, FR6DCPLUS.
Replaces FR7DTC.