---
product_id: 254844578
title: "E3 Spark Plugs E3.40 Premium Automotive Spark Plug with DiamondFIRE Technology, 14mm Thread, 0.460” Reach, Taper Seat, Resistor, Pack of 1"
brand: "e3"
price: "$19.90"
currency: USD
in_stock: true
url: https://www.desertcart.us/products/254844578-e3-spark-plugs-e3-40-premium-automotive-spark-plug-diamondfire
store_origin: US
region: United States of America
---

# DiamondFIRE tech boosts power 4-12% Fuel economy improved by 3-13% Cuts harmful emissions significantly E3 Spark Plugs E3.40 Premium Automotive Spark Plug with DiamondFIRE Technology, 14mm Thread, 0.460” Reach, Taper Seat, Resistor, Pack of 1

**Brand:** e3
**Price:** $19.90
**Availability:** ✅ In Stock

## Summary

> ⚡ Ignite Efficiency, Drive the Future

## Quick Answers

- **What is this?** E3 Spark Plugs E3.40 Premium Automotive Spark Plug with DiamondFIRE Technology, 14mm Thread, 0.460” Reach, Taper Seat, Resistor, Pack of 1 by e3
- **How much does it cost?** $19.90 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.us](https://www.desertcart.us/products/254844578-e3-spark-plugs-e3-40-premium-automotive-spark-plug-diamondfire)

## Best For

- e3 enthusiasts

## Why This Product

- Trusted e3 brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Power Up Your Ride:** Patented DiamondFIRE side-wire electrode delivers a faster, more complete burn for up to 12% more engine power.
- • **Drive Longer, Spend Less:** Boost fuel efficiency by up to 13%, saving you money and reducing pit stops at the pump.
- • **Eco-Friendly Performance:** Lower hydrocarbon emissions and carbon buildup for cleaner, greener combustion that meets modern standards.
- • **Built to Last, Guaranteed:** Backed by a 5-year/100,000-mile warranty, ensuring dependable performance without frequent replacements.
- • **Precision Fit for Classics:** Designed for domestic vehicles (1960s-1990s) with 14mm thread and taper seat for seamless installation and optimal combustion.

## Overview

The E3.40 Premium Automotive Spark Plug features patented DiamondFIRE technology with a unique side-wire electrode that enhances combustion efficiency, delivering up to 12% more power and 13% better fuel economy. Designed for domestic vehicles from the 1960s to early 1990s, it reduces harmful emissions and carbon buildup while offering a durable 5-year/100,000-mile warranty. Its precision 14mm thread and taper seat ensure a perfect fit, making it the smart upgrade for classic car enthusiasts seeking performance and sustainability.

## Description

E3 Spark Plugs E3.40 Premium Automotive Spark Plug with DiamondFIRE Technology, 14mm Thread, 0.460” Reach, Taper Seat, Resistor, Pack of 1

## Features

- FOR DOMESTIC APPLICATIONS: Designed to fit a wide range of domestic vehicles, this spark plug enhances power, improves fuel economy, and reduces harmful hydrocarbon emissions, making it ideal for various engine types and models
- DIAMONDFIRE TECHNOLOGY: Patented side-wire electrode delivers a faster, more complete burn, boosting engine efficiency, with up to 4%-12% more power and 3%-13% better fuel economy depending on engine class
- LOWER EMISSIONS: The more complete burn helps to reduce emissions, minimize carbon buildup, promote cleaner combustion, and support compliance with modern environmental and emissions standards
- PERFORMANCE BUILT: Yttrium-enhanced alloy and colder heat range help prevent pre-ignition and support performance mods by reducing side-wire temperatures and improving combustion
- LONG-LASTING PERFORMANCE: Includes a 5-year/100,000-mile limited warranty for long-lasting use and dependable performance without frequent replacements

## Technical Specifications

| Specification | Value |
|---------------|-------|
| Manufacturer | E3 Spark Plugs |
| Brand | E3 |
| Model | Automotive Spark Plug |
| Product Dimensions | 15.49 x 10.41 x 2.03 cm; 90.72 g |
| Item model number | E3.40 |
| Exterior | Machined |
| Manufacturer Part Number | E3.40 |
| OEM Part Number | E3.40 |
| Position | Center |
| Item Weight | 90.7 g |

## Product Details

- **Brand:** E3
- **Core material:** Copper
- **Top material type:** Alloy Steel
- **Vehicle service type:** Car
- **Global Trade Identification Number:** 00894489000404

## Images

![E3 Spark Plugs E3.40 Premium Automotive Spark Plug with DiamondFIRE Technology, 14mm Thread, 0.460” Reach, Taper Seat, Resistor, Pack of 1 - Image 1](https://m.media-amazon.com/images/I/51Cb6CG7Q8L.jpg)
![E3 Spark Plugs E3.40 Premium Automotive Spark Plug with DiamondFIRE Technology, 14mm Thread, 0.460” Reach, Taper Seat, Resistor, Pack of 1 - Image 2](https://m.media-amazon.com/images/I/51T2lqxZ3QL.jpg)
![E3 Spark Plugs E3.40 Premium Automotive Spark Plug with DiamondFIRE Technology, 14mm Thread, 0.460” Reach, Taper Seat, Resistor, Pack of 1 - Image 3](https://m.media-amazon.com/images/I/61vAJ-Bj7EL.jpg)

## Frequently Bought Together

- E3 Spark Plugs E3.40 E3 Spark Plug (Automotive)
- NGK Spark Plug DPR7EA-9 5129
- NGK Spark Plug DPR8EA-9 4929, Silver

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*Product available on Desertcart United States of America*
*Store origin: US*
*Last updated: 2026-03-12*