# XR5IX NGK Iridium Spark Plug | Genuine NGK Spark Plug

## 🔧 Product Description

**NGK Iridium Spark Plug – Part Number: XR5IX**

Iridium NGK spark plugs offer a longer service life than a standard nickel-tipped spark plug: while nickel-alloy plugs offer a service life of roughly 20,000-40,000km, NGK Iridium IX spark plugs offer a service life of up to 60,000km, so fewer replacements are needed over time despite the higher initial cost.

Precious-metal spark plugs like the NGK Iridium IX also offer higher ignitability, achieved with an exposed fine-tip centre electrode that promotes superior flame growth compared with a standard spark plug. Iridium has a much higher melting point (2410°C) than nickel (1453°C), allowing the centre electrode diameter to be reduced from 2.5mm to 0.6mm – a smaller electrode mass that reduces the impedance to flame progress, helping acceleration, fuel consumption and idle quality.

## ⚙️ Key Features

-   Fine iridium-tipped centre electrode for a slow wear rate and stable idle
-   Longer service life than standard nickel plugs
-   Trivalent metal plating provides superior anti-corrosion and anti-seizing properties
-   Corrugated ribs reduce the risk of flashover
-   Pure alumina silicate ceramic insulator, providing superior strength and better heat transfer
-   Copper core aids in heat removal
-   Triple seals prevent leakage

## 📏 Specifications

-   NGK stock number: 7355
-   Thread: 14 mm
-   Reach: 9.5 mm (3/8 in)
-   Hex: 20.8 mm (13/16 in)
-   Seat: Gasket
-   Terminal: Solid
-   Type: Projected

## 🚘 Application

Listed in NGK's application charts for marine, motorcycle, ATV and snowmobile equipment and automotive vehicles. The gap is not the same on all of them – the chart lists between 0.5 mm and 1.0 mm depending on the engine, so check the line for yours.

-   Chrysler M80 (8 CYL) – Inboard Engine
-   Chrysler M318A (8 CYL) – Inboard Engine
-   Chrysler M318B (8 CYL) – Inboard Engine
-   Chrysler M318C (8 CYL) – Inboard Engine
-   Chrysler M318GD (8 CYL) – Inboard Engine
-   Chrysler M383B (8 CYL) – Inboard Engine
-   Chrysler M383BV (8 CYL) – Inboard Engine
-   Chrysler M400B (8 CYL) – Inboard Engine
-   Chrysler M400BV (8 CYL) – Inboard Engine
-   Chrysler M400S (8 CYL) – Inboard Engine
-   Chrysler M413B (8 CYL) – Inboard Engine
-   Chrysler M413D (8 CYL) – Inboard Engine
-   Chrysler M426B (8 CYL) – Inboard Engine
-   Chrysler M426D (8 CYL) – Inboard Engine
-   Chrysler M426-SKI (8 CYL) – Inboard Engine
-   Chrysler M440B (8 CYL) – Inboard Engine
-   Chrysler M440BJ (8 CYL) – Inboard Engine
-   Chrysler M440BV (8 CYL) – Inboard Engine
-   Chrysler M440D (8 CYL) – Inboard Engine
-   Chrysler M440S (8 CYL) – Inboard Engine
-   Chrysler M440SV (8 CYL) – Inboard Engine
-   Hardin H240J (1990-1969) – Inboard Engine
-   Hardin H240V (1990-1969) – Inboard Engine
-   Hardin H295J (1976-1960) – Inboard Engine
-   Hardin H295V (1976-1960) – Inboard Engine

That is the 25 most common of 387 applications NGK's charts list for this plug – ask us to check yours.

## 🔄 Supersession & Cross Reference

NGK's cross-reference tables list this plug against these part numbers.

-   Autolite: 75, 76, AP85, XS85, XS85DP
-   ACDelco: 41-833, B44S
-   Champion: J13Y, J14YC
-   Motorcraft: A52CU

## 📦 Condition

-   Brand new genuine product
-   Supplied in original packaging

## Details

- **Price:** 58.0 AUD
- **Vendor:** NGK
- **Type:** Ignition & Controls

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 58.00 AUD | In stock |

## Images

- XR5IX NGK iridium spark plug

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> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/xr5ix-ngk-iridium-spark-plug-genuine-ngk-spark-plug)
> Updated: 2026-09-03