How Often To Change Spark Plugs?

A spark plug is a small device that ignites an internal combustion engine’s air and fuel mixture. Not all engines use a spark plug, but it is a critical feature for those that use it. The ignition causes an explosion that makes an engine produce power. It has a threaded metal shell with a ceramic insulator that separates the two electrodes it carries.

Spark plugs set the pistons in motion and provide power to keep your vehicle’s engine running, ensuring that the machines continue to run smoothly and efficiently.

The number of spark plugs a car uses is dependent on the number of cylinders in the car, as one spark plug fits into one cylinder. However, some high-performance vehicles can have two spark plugs per cylinder, depending on the manufacturer.

Because of their delicate role, you often need to replace spark plugs. When you take your car in for maintenance, the mechanic will check the state of your pins and tell you which ones are normal and which you should replace.

How Long Can a Spark Plug Last?

When you change spark plugs, you reduce maintenance costs and improve engine protection. How often you change spark plugs depends on the manufacturer’s recommended time frame. This is usually based on the plug type. Platinum-coated spark plugs are more efficient and can carry for as long as 100,000 miles.

How Long Can a Spark Plug Last

Copper plugs, on the other hand, though more common and inexpensive than others, tend to have a short lifespan of 20,000 to 30,000 miles. However, weather and other conditions may warrant you to change your spark plugs earlier than recommended. The important thing is to pay attention to your car’s early warning signs in between maintenance, as a worn spark plug can cause more costly repairs.

Read also: How long does it take to change spark plugs

6 Signs You Need to Change Spark Plugs

6 Signs You Need to Change Spark Plugs

1. Error Code

Cars from the model year 1996 come with a list of diagnostics trouble codes. This means that if the onboard computer detects a fault, the sensors trigger and show an error code. You can read this error code with a device called an OBD2 scanner. Using this device, you will know which spark plugs you should change. For example, a P0301 error code might indicate a faulty spark plug or spark plug wires.

2. Difficulty in Starting the Car

It is easy to get used to turning the key in your car’s ignition and hearing your car engine come alive. If you have faulty spark plugs, you may find it challenging to start your vehicle. The battery is mostly to blame when a car does not start. However, the issue could be the spark plugs. A build-up of carbon or worn plugs would not provide enough spark to ignite the air and fuel mixture and turn the engine over.

3. Poor Acceleration

The spark plugs are what provide power and make the engine run smoothly. When you notice that your vehicle does not accelerate as quickly as it typically should, you may want to change the spark plugs. Faulty plugs will not give as much power as they need to propel the car.

4. Poor Gas Mileage

Worn-out spark plugs make your engine work harder than usual and reduce fuel efficiency. Your vehicle’s fuel economy will be optimum if the spark plugs are working correctly. As spark plugs get used and wear out, the space between the electrodes expands, causing the plug to fire erratically. So once you notice that your car is using more gas than usual, change the spark plugs.

5. Misfiring Engine

An engine misfiring may sound like a sputter. You may also feel a sudden loss of power or violent shaking when you drive. There may also be popping sounds as the engine losses and regains timing. This misfire is usually the result of at least one spark plug being faulty. Misfiring spark plugs can cause raw fuel or oil to enter the exhaust system and damage the catalytic converter if left unchecked.

6. Check Engine Light

While a ‘check engine’ light coming on can indicate many things, one common reason is one or more bad spark plugs. You might miss the symptoms of a misfiring engine, but an engine not running correctly can trigger the ‘check engine’ light to come on, so if you see this light, you need to check the spark plugs.

If you have noticed any of the signs listed above, you need to check for and change spark plugs. When you change the spark plugs, you will see improved performance. Deciding on the suitable spark plugs to change and where to buy comes down to the relative pros and cons and their cost.

Common Types Of Spark Plugs

Types Of Spark Plugs

1. Copper Spark Plugs

Coated in copper, the diameter of these plugs is larger than other types of spark plugs, making them need more voltage to generate a spark.

  • Inexpensive
  • Performs well in high-compression conditions
  • Requires more voltage
  • Short life spans

2. Platinum Spark Plugs

The electrodes of these types of spark plugs are platinum-coated, and they last longer and tend to generate more heat which reduces the build-up of carbon.

  • More reliable
  • Long lifespan
  • Reduces build-up of carbon
  • More expensive

3. Iridium Spark Plugs

Iridium is stronger and more durable than copper or platinum, so spark plugs coated with iridium tend to last longer. They also have a center electrode which needs minimal voltage for spark generation.

  • Requires less voltage
  • Long lifespan
  • More efficient combustion
  • Very expensive


In conclusion, it is best to follow the owner’s manual or your mechanics’ recommendations for how often to change spark plugs. The critical role spark plugs play in the engine means they will show symptoms when they fail. Weather, oil in the combustion chamber, and excessive carbon build-ups are just some of the reasons there is a need to change spark plugs. The amount of damage will dictate how often to change the spark plugs.

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