A Complete Guide to Choosing the Best Spark Plugs for Your Car Engine

right spark plugs for your engine

Did you know a tiny spark plug can cause big trouble for your car? Studies by the Australian Automobile Association (AAA) show that faulty spark plugs are responsible for 1 in 3 breakdowns.

Spark plugs are important for your engine’s performance and fuel efficiency. But using the wrong ones can lead to misfires, stalling, and a big dent in your pocket. No worries, though. This blog gives you the complete knowledge to choose the right spark plugs for your engine.

What Is the Function of Spark Plugs?

Imagine your car engine as a tiny walled space where lightning strikes regularly. Spark plugs act like mini lighters, creating these sparks. They channel high voltage electricity, making a jump spark across a gap inside the engine cylinder. It ignites the compressed air-fuel mixture, causing a mini-explosion that pushes the pistons and ultimately powers your car.

What Are the Types of Spark Plugs?

Spark plugs come in various types, each with its own strengths. Let’s discuss the three main categories:

  1. According To Materials 


These are your budget-friendly plugs. They offer excellent conductivity for a strong spark but wear down faster due to the softer metal. These are perfect for standard engines and those who prioritise affordability.


A step up in durability, platinum plugs last longer than copper, thanks to the harder metal. They offer better performance and slightly improved fuel efficiency but come at a somewhat higher price.


The undisputed best type of spark plug, iridium has exceptional durability and the longest lifespan. Their fine-tipped electrodes deliver a focused spark, leading to top performance and fuel economy. However, they’re the priciest option.

Remember, your car’s owner’s manual or a licensed mechanic can recommend the ideal material for your specific engine and driving style.

According to the Design

Spark plugs also vary according to their design. The most common ones are:

Single electrode

These have a single central electrode that creates the spark. They’re reliable and affordable but may wear down faster.

Multi electrode

These feature multiple electrodes around a central one. This design offers a better range of spark possibilities, improving performance and extending lifespan.

According To the Operating Temperature

Spark plugs aren’t one-size-fits-all when it comes to temperature. They have a heat range that determines how efficiently they dissipate heat. Hotter plugs are better for high-performance engines, while colder plugs suit cold-start situations or engines exposed to overheating.

Using the wrong heat range can create problems like overheating (hot plugs in a standard engine) or fouling (cold plugs in a hot engine). We’ll give you more details on this later.

What Factors to be Considered When Selecting a Spark Plug for an Engine?

Choosing the right spark plugs isn’t a one-shot deal. Here are some key factors you should consider:

  • Material

As we discussed earlier, the material (platinum, copper, or iridium) plays a role. See your owner’s manual or consult a mechanic for the recommended material based on your car and driving.

  • Size 

Spark plugs come in different sizes, with variations in thread diameter and reach (length). Using the correct size helps proper fit and function within the engine. Imagine putting a square peg in a round hole. It just wouldn’t work.

  • Heat Range

Think of heat range as a spark plug’s tolerance for engine temperature. Hotter plugs are better suited for high-performance engines that generate much heat. Colder plugs work well in cold-start situations.

Using the wrong heat range can lead to issues. For example, a hot plug in a standard engine might overheat, while a cold plug in a hot engine could get fouled by unburnt fuel deposits. The table below provides a quick guide:

Recommended Heat Range for Different Engine Types


Engine Type Recommended Heat Range
Standard Engine Standard Heat Range
High-Performance Engine Colder Heat Range
Cold-Start Applications Colder Heat Range


  • Gap Style

The spark plug gap is the tiny space between the centre and ground electrodes where the spark jumps. This gap gives proper spark ignition. Some spark plugs come pre-gapped, while others might require adjustment.

If you’re unsure about gap specifications, it’s always best to consult your owner’s manual or seek help from a professional. Remember, even a slightly incorrect gap can affect engine performance.

Considering selling your old car? Once you’ve replaced your spark plugs, you might consider an upgrade. We offer eco-friendly junk car removal, pay cash on the spot and complete the paperwork.

What Are The Symptoms Of Bad Spark Plugs?

Like a weak flashlight struggles to light the way, failing spark plugs can cause your car’s performance issues. Here are some signs:

  • Engine misfires

This can feel like a jerking or sputtering sensation while driving.

  • Difficulty starting the engine

Your car might crank but hesitate to start or take multiple attempts.

  • Reduced fuel efficiency

Faulty spark plugs can lead to incomplete combustion, causing you to burn more fuel for the same distance.

  • Rough idling

You might feel vibrations in the car when idling at a stoplight.

If you experience any of these symptoms, get your spark plugs checked by an expert for the best fuel efficiency.

Why Are Different Spark Plugs Needed For Each Engine Type?

Engines come in all shapes and sizes, just like the cars they power. High-performance engines generate a lot of heat, while those in colder climates must cope with frosty mornings. Spark plugs are designed to operate within specific temperature ranges.

The right spark plug for your engine acts like a Goldilocks zone. Not too hot or cold. Using the wrong one can disrupt this delicate balance.

So, choosing the right spark plug offers longevity for your engine. After all, a happy engine means a happy car, which means you can enjoy more road trips and adventures. If you want to upgrade your car and get some cash, we offer the highest cash for cars in Darwin.


 Choosing the right spark plug for your engine is like picking the perfect key. It unlocks smooth performance and fuel efficiency. Now you can make an informed decision. If it’s time to trade in your old spark plugs and your car itself, PS Car Removal can help. We buy cars in Darwin, offering a quick and convenient way to get cash for your old car. Ready to give your car and pocket a boost? Check out other blogs on our website, or give us a call today.