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This NGK Iridium IX spark plug (TR55IX) is supplied as an OEM-grade replacement. Part of the NGK Iridium IX range. Thread M14 x 1,25. Verify VIN/engine before ordering.
Common fitments include Mazda (MX-5). Always confirm the correct heat range and electrode design for your specific engine variant by VIN before ordering.
Important: Spark plugs are not returnable, exchangeable, or refundable once fitted. Confirm you are ordering the correct part for your vehicle. Compare the new spark plug to the removed plug for thread reach, thread diameter, hex size, electrode style, gap specification, and heat range before fitting. Mismatched spark plugs can cause misfires, pre-ignition, detonation, fouling, or engine damage.
Returns Notice: Once a spark plug has been fitted or threaded into a cylinder head, it cannot be returned, exchanged, or refunded under any circumstances.
Will this NGK spark plug fit my Mazda?
This part (TR55IX) is listed for the applications shown on this page. Always confirm the correct heat range, thread size and electrode design against your vehicle's service manual or a parts lookup before ordering. Verify VIN/engine.
What does the NGK part code mean?
The NGK trade number encodes physical and performance characteristics - thread/reach, electrode design, heat rating, and projection. Each digit and letter has meaning in NGK's naming convention. The heat range is usually the standalone digit (e.g. BPR6ES is heat range 6).
What is the difference between this NGK plug and a Bosch / Champion / Denso equivalent?
The cross-references listed under OEM Reference Numbers are functionally equivalent for the same applications, but materials, electrode design and heat dissipation can differ slightly. NGK is OEM-supply quality and most manufacturers specify NGK or Denso as their factory plug.
How do I confirm fitment if my engine variant isn't listed?
Match the supplied thread size, reach, electrode design and heat range against your existing plug. If unsure, request fitment assistance before ordering.
