Different Types of Spark Plugs for Cars: A Comprehensive Guide

Author: Unknown•Published on: 1/12/2026•5 Minutes
Overview:While there is an increased focus on electric vehicles by carmakers and governments, most of the car buyers still find their ‘spark’ of interest in petrol-powered cars. Speaking of spark, the ignition system of a petrol car has a spark plug at its heart. Positioned at the top of the combustion chamber of the engine’s cylinders, spark plugs initiate the burning of the air-fuel mixture, which in turn brings a car to life. Given the significance of spark plugs in a car's performance, efficiency and emissions, carmakers prefer different types of spark plugs for various vehicles. The following are the varieties of spark plugs for cars that differ based on their design, materials and performance.
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Key Highlights:


  • There are three types of spark plugs: copper, platinum and iridium.
  • Platinum spark plugs are most widespread, as they offer a perfect balance of cost, efficiency and performance.
  • While iridium spark plugs provide the best performance, they are also the most expensive.

Copper Spark Plugs


The most commonly preferred spark plugs in the mainstream automotive industry, especially in older compact mass-market cars sold in India, copper spark plugs are also the cheapest and most basic of their type. Copper spark plugs have a core made of solid copper, with their outer electrode made of nickel alloy.


Among all types of spark plugs, copper spark plugs have the shortest lifespan of around 20,000-30,000 km. This short lifespan is particularly due to the sooner wear of the nickel alloy outer electrode by the extreme heat generated within the combustion chamber.


Due to their inexpensiveness and good heat conductivity, copper spark plugs are preferable for cost-effective compact cars. The short lifespan means that these spark plugs require replacement sooner, along with a slight compromise in fuel efficiency over time.


Platinum Spark Plugs


Considered a mid-level type of its kind, the platinum spark plugs, as the name suggests, have a platinum disc welded to the tip of a standard electrode, with some spark plugs also using a solid platinum electrode.


Since platinum has a higher melting point than nickel alloy, it maintains its sharp edge for a longer time, resulting in a longer lifespan that extends to 60,000-80,000 km. While they are more expensive than copper spark plugs, these platinum spark plugs are now more preferred for new-generation mass-market cars due to their better efficiency and longer replacement interval.


Iridium Spark Plugs


The best and most effective of its kind, iridium spark plugs use an iridium tip, which is even stronger than platinum, making it more durable in the long run. Besides having an iridium tip, these spark plugs have a thin wire centre electrode for improved firing efficiency.


These best-in-industry properties of iridium spark plugs give it a lifespan that lasts beyond 1,00,000 km. This increased durability makes it a more preferable option for luxury and sports cars, which run on modern and performance-oriented turbocharged engines. However, due to the use of expensive materials, iridium spark plugs are the costliest to buy.


Benefits of a Good Spark Plug


By now, you know which type of spark plug is suitable for which car, based on aspects such as durability, fuel efficiency and performance boost. A good spark plug ensures the best possible air-fuel combustion with reduced levels of soot formation, which is essential for engine durability, smooth acceleration, enhanced fuel efficiency and reduced emissions. However, do note that spark plugs should be replaced at the end of their lifecycle, as prolonged use beyond their deterioration can lead to ineffective combustion.


Choosing the Right Spark Plug for Your Car


Among the three types of spark plugs, copper spark plugs are gradually becoming a thing of the past due to their low durability, despite having a cost advantage over the others. Platinum spark plugs are now a more popular choice among mainstream car buyers, for they offer a nice balance of performance, durability and value. However, for range-topping performance-oriented cars, nothing comes close to the excellence of iridium spark plugs.


Before choosing the correct spark plug for your car, always consider the OEM recommendations and engine compatibility, generally mentioned in the owner’s manual. Besides the type and material of the electrode, the efficiency of spark plugs also depends on other factors such as driving style, environment and the brand.


FAQs


1. What are the different types of spark plugs?
There are three types of spark plugs available for cars: copper, platinum and iridium. All of them are differentiated based on the material of the electrode.


2. Which type of spark plug is best?
Iridium spark plugs are considered the best as they deliver the highest boost in performance, efficiency and durability. However, due to the high cost of iridium, these spark plugs do come at a price and are usually preferred only for high-end luxury and performance cars.


3. Can spark plugs affect gas mileage?
A spark plug is the most crucial component of a vehicle’s ignition system, as it is solely responsible for producing the spark that burns the air-fuel mixture within an engine’s combustion chamber. An ineffective spark plug might result in incomplete air-fuel combustion, negatively affecting the vehicle’s performance, efficiency, acceleration and durability.