Is the Denso Iridium TT 4705 a direct replacement for my stock plug?

It is a direct-fit plug for many original-equipment applications, but Denso lists coverage by engine, not by car model alone. Check the part number against your engine's specified plug before ordering.

How is it different from Denso Iridium Power?

Both use a 0.4 mm iridium center electrode. The TT adds a platinum ground electrode for longer service life, while Iridium Power is tuned more toward spark performance.

Do I need to gap it before installing?

Denso ships these plugs pre-gapped for their listed applications. If you check the gap, use a wire gauge and avoid prying on the fine iridium tip.

How many should I buy?

It is sold as a single plug, so buy one per cylinder. Replacing the whole set at once keeps the ignition even across the engine.

How often should it be changed?

Iridium plugs typically last far longer than copper or platinum, but follow your owner's manual interval. Some owners report early failures, so watch for misfires.