NGK Iridium spark plug set for 2006-15

Super-Duper NGK Iridium spark plugs to fit the 2.0 NC. These are the plugs that Mazda specifies. Note that these will NOT fit the 1.8 NC engine - they're too long and will cause physical damage. 

What makes them so super-duper? According to NGK: "Laser Iridium spark plugs provide superior ignitability and long service life. Smallest tip diameter available Iridium / Platinum surfaces ensure slow wear rate providing stable idle, superior anti fouling, improved fuel efficiency and lower emissions".

Should you use anti-seize? Short answer, no, not on these. Here's the longer answer, straight from NGK: "NGK spark plugs feature trivalent plating. This silver or chrome-colored finish on the threads is designed to provide corrosion resistance against moisture and chemicals. The coating also acts as a release agent during spark plug removal. NGK spark plugs are installed at the factory dry, without lubrication or anti-seize."

So there you go. Your Miata deserves it!

Full set of four plugs. Recommended stock gap is 0.050-0.053". Boosted applications, especially higher boost, might need a tighter gap.