Anybody using heat range 9 irridium plugs. Having a few intermittent misfire issues which at the moment i rekon are down to the plugs been too cold. Whats other peoples experiences and have you changed back to 8's.
Im using NGK plugs, car running somewhere in the region of 380 to 400 bhp id guess, 3071r at 1.4bar.
Im using NGK plugs, car running somewhere in the region of 380 to 400 bhp id guess, 3071r at 1.4bar.