How often should you change iridium spark plugs

They are integral to a smooth drive as they ignite the fuel-air mix in combustion engines, providing the power you need.

If they aren’t changed when they’re past their effectiveness, it could introduce problems for your engine.

What do spark plugs do?

Each plug screws into the top of every cylinder in your engine.

So if you have a four-cylinder engine, you’ll have four plugs, while a six-cylinder engine has six and so on.

The part of the spark plug that sticks into the cylinder is the terminal  – where the spark is generated.

The electricity generated by the car’s ignition system first flows through the centre electrode, one of two.

When the electricity jumps the gap between the centre electrode and the second one, a spark is formed.

That ignites the fuel-air mixture at the optimum time within the cylinder, forcing the piston down and turning the crankshaft.

When is it time to change them?

To be clear, spark plugs don’t need to be changed very often and are designed to withstand huge amounts of punishment.

Some cars only need replacement spark plugs after 100,000km, some up to 120,000km.

Refer to your owners’ manual: it will recommend when you need to replace your engine’s spark plugs.

Different materials have different lifespans: copper wears out the fastest, while iridium- or platinum-tipped plugs last the longest.

However, no matter what material, spark plugs are exposed to high temperatures and pressures and develop wear and tear after repeated sparkings.

Carbon deposits can build up on the electrodes, affecting the sparking efficiency and hence, engine effectiveness.

Unfortunately, there is no single answer to this question. As spark plugs grow older, they lose their sharp edges as material from the center and ground electrodes is slowly eroded away. As the gap between these two points grows, the voltage required to bridge the gap increases proportionately. Even the best ignition systems will be strained to supply enough voltage to completely burn the fuel. It is at this point, when fuel is being left unburned, that the time has come to change spark plugs.

Replacing worn out spark plugs with new ones (with sharp new edges) effectively restores the ignition system’s efficiency. Misfires are reduced, power is restored, economy of operation is enhanced, and emissions are reduced.

The best guide is the manufacturer’s recommendation for your vehicle, as this particular service varies from brand to brand and model to model. In the absence of this information or in conjunction with it, you can rely on the advice of a service technician who is familiar with your type of vehicle. In the best of all worlds, this would be a service technician who is also familiar with the vehicle you own. If you find a good service technician, whether dealer or independent, stick with them. The better he knows your personal vehicle, the better he will be able to diagnose and service it. The end result is very much like a doctor-patient relationship and, in the long run, you will have a healthier vehicle.

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An automobile engine needs gas, air, and spark to get its internals chugging along like our childhood pal Thomas. Without any one of these, the engine will falter and you won’t be making it up that hill. 

While the automotive industry shifts toward fully electric vehicles at this very moment, internal combustion engines have relied on a strike of electricity all along. The spark plug is responsible for creating a car’s all-important spark to ignite the gas and fuel mixture, and if it’s damaged or incorrectly set, it can lead to a malfunctioning, or dead-as-a-doornail, car. 

Spark plugs do require maintenance and replacement, but there’s no specific rule of law as to when they need servicing. It’s up to you, the owner, to regularly check your plugs and to recognize signs of a faulty plug. The Drive’s callused info team will show you how.

What Is a Spark Plug?

A spark plug is a small device that plugs into the engine, more specifically into the cylinder, and provides the spark for combustion via a conduit connecting the battery to the spark plug. A household consumer engine typically has as many spark plugs as there are cylinders, so an inline-four has four plugs, and a V8 has eight plugs. Some cars, however, feature two spark plugs per cylinder for more precise ignition. 

Spark plugs are made up of a bunch of small parts that use copper, nickel, iridium, and platinum, among others. For protection and insulation, spark plugs also use ceramic.

What Does a Spark Plug Do? 

A spark plug creates a small string of high-voltage electricity within a specifically measured gap between a center electrode and a ground electrode. This spark occurs within the cylinder and ignites the air and fuel mixture. This explosion pushes the piston back down the cylinder.

Symptoms of Faulty Spark Plugs

If a car’s spark plugs are fouled, improperly gapped, or dead, it could exhibit one or more of these symptoms:

• Car won’t start or struggles to start
• The car idles poorly
• Engine knocking or pinging
• Worse-than-normal fuel economy
• Suffering performance

How To Change Spark Plugs

With the correct tools, checking and changing spark plugs can be accomplished by even amateur DIYers! For a complete breakdown, check out The Drive’s step-by-step guide, How To Change Spark Plugs.

How To Gap Spark Plugs

For a spark plug to deliver precisely the right amount of electricity at the correct time, it needs to be gapped correctly. Spark plug gaps can be checked and maintained with a spark plug gap tool, and we’ve got you covered on that too. For more information, read The Drive’s guide, How To Gap a Spark Plug.

Get Help From a Mechanic On JustAnswer

Although The Drive’s detailed how-to guides are easy to follow, a rusty bolt, an engine component not in the correct position, or a messy oil leak can derail a project. That’s why we’ve partnered with JustAnswer, which connects you to certified mechanics around the globe, to get you through even the toughest jobs. 

So if you have a question or are stuck, click here and talk to a mechanic near you. 

FAQs About Spark Plugs

You’ve got questions, The Drive has answers!

Q: So How Much Does It Cost To Change Spark Plugs?

A: For commonplace consumer vehicles, a single spark plug will typically cost about $2-20. If you’re changing the plugs on a used Bugatti Veyron, well, be prepared to pay a little bit more. 

Q: Ok, Then How Often Should Spark Plugs Be Replaced?

A: If you want to use a hard rule for changing spark plugs, rather than changing based on the condition of the plug, they should be serviced roughly every 30,000 miles. However, know that they might fail sooner than that, or a lot later.

Q: Should You Replace All Spark Plugs At Once?

A: Yes, as a general rule, it’s better to replace all plugs at the same time to ensure consistent levels of performance. No half-measures in this garage.

Q: But What Happens If You Don't Change Your Spark Plugs?

A: Driving with bad spark plugs could lead to poor performance, poor fuel economy, misfires, or your car might not even start. At worst, they could cause extra wear to your engine.

Q: And What Happens If You Don’t Gap Your Spark Plugs?

A: If the gap on your spark plug isn’t set to the correct specification, you might get misfires or knock or see carbon build-up or excess fuel. Always check if the gap is correct.

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