# UR5IX NGK Iridium Spark Plug | Genuine NGK Spark Plug

## 🔧 Product Description

**NGK Iridium Spark Plug – Part Number: UR5IX**

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: 7177
-   Thread: 14 mm
-   Reach: .460"
-   Hex: 16 mm (5/8 in)
-   Seat: Tapered
-   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.

-   American Challenger EAGLE 400 – Inboard Engine
-   American Challenger EAGLE 600 – Inboard Engine
-   American Challenger EAGLE 800 – Inboard Engine
-   Berkeley FORD (302 CID, 14MM HDS., 1990-1974) – Inboard Engine
-   Berkeley FORD (351 CID, 14MM HDS., 1990-1974) – Inboard Engine
-   Berkeley FORD BIG BLOCK (460 CID, 1990-1976) – Inboard Engine
-   Chrysler M460B (8 CYL) – Inboard Engine
-   Flagship (292 CID, 1974-1971) – Inboard Engine
-   Flagship (300 CID, LIGHT SERVICE, 1977) – Inboard Engine
-   Flagship (305 CID, 1974-1971) – Inboard Engine
-   Flagship (305 CID, LIGHT SERVICE, 1977-1975) – Inboard Engine
-   Flagship (307 CID, 1974-1971) – Inboard Engine
-   Flagship (350 CID, 1974-1971) – Inboard Engine
-   Flagship (454 CID, 1974-1971) – Inboard Engine
-   Flagship (454 CID, LIGHT SERVICE, 1977-1975) – Inboard Engine
-   Hardin H240J (1990-1969) – Inboard Engine
-   Hardin H240V (1990-1969) – Inboard Engine
-   Hardin HM225 (1990-1983) – Inboard Engine
-   Hardin HM260 (1990-1983) – Inboard Engine
-   Hardin HM280 (1990-1983) – Inboard Engine
-   Hardin HM333 (1990-1983) – Inboard Engine
-   Hardin HM400 (1990-1983) – Inboard Engine
-   Hardin HM405 (1990-1983) – Inboard Engine
-   Hardin HM430 (1990-1983) – Inboard Engine
-   Indmar 5.7L V8 (8 CYL GM SMALL BLOCK, 1987-1976) – Inboard Engine

That is the 25 most common of 227 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.

-   DENSO: 4716, 5330, 7177, IFT16, ITF16, ITF20TT
-   Autolite: XP24, XP24DP2, XP25, XP25DP2
-   Bosch: 4448, 4502, H8BP, HGR9BQI
-   ACDelco: 1, 10, 2
-   Motorcraft: AF42, ASF32P, SP501
-   Champion: V12YC

## 📦 Condition

-   Brand new genuine product
-   Supplied in original packaging

## Details

- **Price:** 40.0 AUD
- **Vendor:** NGK
- **Type:** Ignition & Controls

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 40.00 AUD | In stock |

## Images

- UR5IX NGK iridium spark plug
- UR5IX NGK iridium spark plug firing end

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> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/ur5ix-ngk-iridium-spark-plug-genuine-ngk-spark-plug)
> Updated: 2026-09-03