---
product_id: 42694642
title: "Autolite 25 Copper Resistor Automotive Replacement Spark Plugs (4 Pack)"
brand: "autolite iridium ultra"
price: "$41"
currency: NZD
in_stock: true
url: https://www.desertcart.nz/products/42694642-autolite-25-copper-resistor-automotive-replacement-spark-plugs-4-pack
store_origin: NZ
region: New Zealand
---

# Built-in resistor reduces RFI & electrode erosion 100% leak-proof copper-glass seal Full copper core for max thermal conductivity Autolite 25 Copper Resistor Automotive Replacement Spark Plugs (4 Pack)

**Brand:** autolite iridium ultra
**Price:** $41
**Availability:** ✅ In Stock

## Summary

> ⚡ Ignite your drive with Autolite’s copper-powered spark plugs – performance you can feel!

## Quick Answers

- **What is this?** Autolite 25 Copper Resistor Automotive Replacement Spark Plugs (4 Pack) by autolite iridium ultra
- **How much does it cost?** $41 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.nz](https://www.desertcart.nz/products/42694642-autolite-25-copper-resistor-automotive-replacement-spark-plugs-4-pack)

## Best For

- autolite iridium ultra enthusiasts

## Why This Product

- Trusted autolite iridium ultra brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Durability That Lasts:** Heat-fused internal seal guarantees leak-proof, long-lasting spark plugs
- • **Precision Engineering:** Cold-formed steel shell with precision rolled threads for a perfect fit every time
- • **Fuel-Savvy Performance:** Optimized for quick starts, smoother acceleration, and improved fuel economy
- • **Trusted Legacy Since 1936:** Backed by decades of innovation and reliability in spark plug technology
- • **Unmatched Thermal Efficiency:** Copper core electrode ensures peak performance in all driving conditions

## Overview

Autolite 25 Copper Resistor Spark Plugs feature a full copper core electrode for superior thermal conductivity, a leak-proof copper-glass seal for durability, and an integrated resistor to minimize radio frequency interference and electrode wear. Designed for quick starts, enhanced fuel efficiency, and smooth acceleration, these plugs combine precision engineering with a trusted legacy since 1936, making them the go-to choice for reliable automotive ignition performance.

## Description

Autolite Copper Core Spark Plugs deliver quick starts, good fuel economy, and smooth acceleration. The copper-glass seal bonds insulator and terminal post center electrode together to ensure full required voltage at spark gap, creating a gas-tight seal that is 100 percent leak-proof. Copper Core spark plugs feature a cold-formed steel shell and precision rolled threads, and a one-piece terminal post that adds strength. The multi-rib insulator reduces the danger of "flash-over" to prevent misfires, and the resistor reduces radio frequency interference (RFI) and electrode erosion. The full copper core electrode provides better performance in all conditions. Autolite Copper Core plugs are your industry standard.

## Features

- MAXIMUM PERFORMANCE: Every Copper Spark Plug has a full copper core electrode which provides higher thermal conductivity for better performance in all conditions
- IMPROVED DURABILITY: All Autolite spark plugs are Leak proof and come with a heat fused internal seal for long lasting durability
- CONSTRUCTION: These replacement spark plugs have a copper-glass seal which bonds the insulator and the terminal post center electrode together
- FUEL EFFICIENCY: The Autolite copper automotive replacement spark plug are guaranteed to deliver quick starts, better fuel economy and smooth acceleration
- AUTOLITE ADVANTAGE: Since 1936, Autolite has been a trusted leader and innovator in spark plug technology. You can count on our copper plugs for performance and value, backed by decades of experience and passion

## Technical Specifications

| Specification | Value |
|---------------|-------|
| Brand | Autolite Iridium Ultra |
| Core Material | Copper |
| Thread Size | RM |
| Top Material Type | Alloy Steel |
| Vehicle Service Type | Motorcycle |
| Global Trade Identification Number | 00009100003690 |
| Automotive Fit Type | Vehicle Specific Fit |
| UPC | 009100003690 |
| Manufacturer | FRAM |
| Model | 25-4PK |
| Item Weight | 1.76 ounces |
| Product Dimensions | 1 x 3.88 x 3.38 inches |
| Item model number | 25-4PK |
| Is Discontinued By Manufacturer | Yes |
| Exterior | Chrome |
| Manufacturer Part Number | 25-4PK |
| Position | Front, Rear |

## Product Details

- **Brand:** Autolite Iridium Ultra
- **Core Material:** Copper
- **Thread Size:** RM
- **Top Material Type:** Alloy Steel
- **Vehicle Service Type:** Motorcycle

## Images

![Autolite 25 Copper Resistor Automotive Replacement Spark Plugs (4 Pack) - Image 1](https://m.media-amazon.com/images/I/71-GAahSRNL.jpg)
![Autolite 25 Copper Resistor Automotive Replacement Spark Plugs (4 Pack) - Image 2](https://m.media-amazon.com/images/I/51RL8QgO9vL.jpg)
![Autolite 25 Copper Resistor Automotive Replacement Spark Plugs (4 Pack) - Image 3](https://m.media-amazon.com/images/I/71sRR+tS62L.jpg)
![Autolite 25 Copper Resistor Automotive Replacement Spark Plugs (4 Pack) - Image 4](https://m.media-amazon.com/images/I/71MGX4XYJQL.jpg)
![Autolite 25 Copper Resistor Automotive Replacement Spark Plugs (4 Pack) - Image 5](https://m.media-amazon.com/images/I/71OdKPYQstL.jpg)

## Available Options

This product comes in different **Number of Items** options.

## Questions & Answers

**Q: Is there only 1 per package?**
A: this is one spark plug for .99 plus shipping charges.

**Q: how many are in the package?**
A: One per package

**Q: can these be used in a 2009 twin cam harley?**
A: No I do not show Autolite 25 to be listed for any Harley Davidson.

**Q: Will this work in lawn mower briggs & stratton engine?**
A: I purchased see these for a Ford 302 V8. While plugs go into a variety of engines Im not so sure about a mower. If you no longer have the manual for your engine I would take some photos of any markings on it and go to a mower shop. Any decent place should be able to look it up from the serial number.  Better yet, remove the old plug and use the same one.

## Frequently Bought Together

- Autolite 25 Copper Resistor Automotive Replacement Spark Plugs (4 Pack)
- Motorcraft DH411B Distributor Cap,Grey
- Motorcraft DR374B Rotor, Large

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**Shop now:** [https://www.desertcart.nz/products/42694642-autolite-25-copper-resistor-automotive-replacement-spark-plugs-4-pack](https://www.desertcart.nz/products/42694642-autolite-25-copper-resistor-automotive-replacement-spark-plugs-4-pack)

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*Product available on Desertcart New Zealand*
*Store origin: NZ*
*Last updated: 2026-02-14*