DENSO Iridium TT Spark Plug • ITV20TT

Suitable for Mazda MX-5 Mk3 / Mk3.5 / Mk3.75 (NC) 2.0 petrol models. This plug is for the 2.0 engine only; the MX-5 NC 1.8 uses a different spark plug specification.

DENSO ITV20TT is an Iridium TT spark plug suitable for the Mazda applications listed below. It uses DENSO's fine twin-tip electrode design, combining a 0.4 mm iridium-alloy centre electrode with a 0.7 mm needle-type platinum-alloy ground electrode.

The fine electrode arrangement is designed to reduce the quenching effect around the initial spark and support reliable ignition and stable combustion. ITV20TT is an application-specific, long-reach taper-seat spark plug and should not be substituted purely on the basis of thread diameter or general plug dimensions.

Product Specifications

• Brand: DENSO
• Product range: Iridium TT
• Part number: ITV20TT
• DENSO secondary part number: 267700-8250
• DENSO trade number: 4719
• DENSO specification number: IT19
• GTIN / EAN: 042511047198
• DENSO heat range: 20
• Seat type: Taper seat
• Thread diameter: 14 mm
• Thread size: M14 x 1.25
• Thread reach: 25 mm
• Hex / spanner size: 16 mm
• Spark gap: 1.0 mm
• Projection: 1.5 mm
• Spark position: 3.0 mm
• Ground electrode height: 6.2 mm
• Centre electrode: 0.4 mm iridium alloy
• Ground electrode: 0.7 mm needle-type platinum alloy
• Ground electrodes: 1
• Terminal type: Solid SAE
• Resistor: 5 kΩ
• Recommended tightening torque: 22 Nm
• Quantity required per MX-5: 4
• Quantity supplied: 1 spark plug

Typical Reasons for Replacement

Spark plugs are routine ignition-system service components and may require replacement because of normal electrode wear, accumulated service mileage or scheduled maintenance. Worn or unsuitable plugs can contribute to symptoms such as difficult starting, an uneven idle or ignition misfire, although these symptoms can also have other causes and should be diagnosed correctly.

Fitment Advice

The MX-5 application for ITV20TT is the 2.0-litre Mk3 / NC engine. Do not use this listing for the 1.8-litre MX-5 NC, which uses a different plug specification.

When replacing spark plugs, replacing all four plugs as a matched set is recommended. Start each plug carefully by hand to minimise the risk of cross-threading and use the correct spark-plug socket and tightening procedure.

The plug is supplied with its specified gap. Do not alter the spark-plug gap unless the applicable DENSO or Mazda service information specifically requires this for the vehicle being worked on.

For imported, modified or previously repaired cars, matching the part number or component style on the part being replaced is recommended.

Other Items to Consider

• Additional ITV20TT spark plugs to complete a four-plug vehicle set
• Ignition coils
• Engine air filter
• Engine oil and oil filter when completing a routine service

Useful Tools / Consumables

• 16 mm spark plug socket
• Suitable extension and ratchet
• Torque wrench
• Compressed air or suitable cleaning equipment for the spark-plug wells

Difficulty Guide

DIY Difficulty: Moderate. Spark-plug replacement is a routine service operation, but correct plug identification, careful thread engagement and appropriate tightening torque are important.

Why DENSO?

DENSO is a long-established Japanese automotive component manufacturer and ignition specialist. Its Iridium TT spark plugs use a fine 0.4 mm iridium centre electrode together with a 0.7 mm platinum twin-tip ground electrode, drawing on DENSO's extensive experience in automotive ignition technology.

What's in the Box?

• 1 x DENSO ITV20TT Iridium TT spark plug

Installation Notes

Install only into a cool engine. Ensure the plug wells are clean before removing the old plugs, start the replacement plug by hand and avoid cross-threading or over-tightening. Use the appropriate vehicle service procedure and tightening specification.