# UR55IX NGK Iridium Spark Plug | Genuine NGK Spark Plug

## 🔧 Product Description

**NGK Iridium Spark Plug – Part Number: UR55IX**

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: 7272
-   Thread: 14 mm
-   Reach: .460"
-   Hex: 16 mm (5/8 in)
-   Seat: Tapered
-   Terminal: Solid
-   Type: Projected, Wide Gap

## 🚘 Application

Listed in NGK's application charts for automotive vehicles.

-   Buick Century (1992-1984) – 4-8 per engine
-   Buick Skylark (1991-1983) – 4-8 per engine
-   Buick Somerset (1987-1986) – 4-8 per engine
-   Buick Somerset Regal (1985) – 4-8 per engine
-   Chevrolet Astro (1990-1985) – 4-8 per engine
-   Chevrolet Camaro (1986-1984) – 4-8 per engine
-   Chevrolet Celebrity (1990-1984) – 4-8 per engine
-   Chevrolet Citation II (1985-1984) – 4-8 per engine
-   Chevrolet LLV (1993-1987) – 4-8 per engine
-   Chevrolet Lumina (1992-1990) – 4-8 per engine
-   Chevrolet Monza (1978) – 4-8 per engine
-   Chevrolet S10 (1993-1985) – 4-8 per engine
-   Chevrolet S10 Blazer (1988-1985) – 4-8 per engine
-   Chevrolet Vega (1975) – 4-8 per engine
-   Ford E-350 Econoline Club Wagon (1996-1992) – 4-8 per engine
-   Gmc S15 (1990-1985) – 4-8 per engine
-   Gmc S15 Jimmy (1988-1985) – 4-8 per engine
-   Gmc Safari (1990-1985) – 4-8 per engine
-   Gmc Sonoma (1993-1991) – 4-8 per engine
-   Oldsmobile Calais (1987-1985) – 4-8 per engine
-   Oldsmobile Cutlass Calais (1991-1988) – 4-8 per engine
-   Oldsmobile Cutlass Ciera (1992-1984) – 4-8 per engine
-   Oldsmobile Cutlass Cruiser (1990-1987) – 4-8 per engine
-   Oldsmobile Omega (1984) – 4-8 per engine
-   Oldsmobile Starfire (1978) – 4-8 per engine

That is the 25 most common of 33 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.

-   ACDelco: 41-816, 41-826
-   DENSO: 7272, ITF16
-   Bosch: HR8BCY
-   Motorcraft: ASF42-6C

## 📦 Condition

-   Brand new genuine product
-   Supplied in original packaging

## Details

- **Price:** 39.0 AUD
- **Vendor:** NGK
- **Type:** Ignition & Controls

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 39.00 AUD | In stock |

## Images

- UR55IX NGK iridium spark plug
- UR55IX NGK iridium spark plug firing end

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> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/ur55ix-ngk-iridium-spark-plug-genuine-ngk-spark-plug)
> Updated: 2026-09-03