How often to change Spark Plugs? Is it that important?

Once you purchase a car, it’s important to keep it maintained to ensure its performance. Spark Plugs are a vital part of a car that requires frequent changing to sustain the car’s functions and not lead to any long-term complications. Spark plugs play a huge role in a car’s engine and allow it to produce power. Thus, if you have a car, then understanding spark plugs can help you to protect yourself from the horrible consequences of leaving a worn-out or failing spark plug in the car.

Spark Plug is the element that drives the engine to operate and emits electricity to boost the engine. Just like any glue that holds two things together, the spark plug is responsible for filling the gap between the combustion and the engine, acting as a spark that drives the car to start and run. Therefore, their maintenance is crucial and can prevent your car from having poor engine performance and high fuel consumption.

If you’re wondering how a spark plug operates and the signs to look out for while giving it a check-up, know that we have all your queries noted and resolved here. This blog post will list down all the information on spark plugs that you must know, including how often to change spark plugsthe benefits of replacing spark plugs, and the indicators of worn-out spark plugs that need replacement.

We will also guide you on where to get spark plugs from and tell you about all the suitable spots from where you can get your spark plug’s replacement.

So, without wasting any more time, let’s begin right away!

Spark Plug – What is it?

Before highlighting the symptoms of a deteriorated Spark Plug, it is important to know what exactly a spark plug is, and its function in the engine.

A spark plug is a device that is placed inside the cylinder of the internal combustion engine. Once you start the ignition, this small piece helps the engine to start by producing an electrical spark.

Here is how it works: it is situated in the head of the combustion unit, and is supported by two electrodes which are divided by an air gap This air gap gives the space for current to release into the engine. They are made of many smaller parts from various materials including copper, nickel, platinum, iridium, and many others. Moreover, many spark plugs are also made with ceramic to ensure protection from electrical shock by providing insulation.

The number of spark plugs varies from car to car. A normal engine typically has the same number of spark plugs as the cylinders; thus, an inline-four has four spark plugs, a V8 has eight spark plugs, etc. However, many cars also have just two cylinders and spark plugs, so it is important to know how many plugs your car has!

Signs that your Spark Plug needs a replacement

Now that you know what a spark plug is, here are some indications of a bad spark plug that you must look for. These signs can help you identify the problem in spark plugs and hence will let you know how often to change spark plugs.

1. The check engine light turns on suddenly

If you are driving your car, and the check engine light turns on or starts flashing: it’s a sign that your spark plug needs attention. This is one of the most common reasons for a check engine light.

The light on is suggesting that your engine is misfiring, and causing it to lose its performance. If you suspect that the engine is misfiring due to the spark plugs then you should look for irregular idling, uneven power during acceleration, and an escalation in exhaust emissions, to ensure your suspicion is correct.

However, always remember that there may be other reasons for the engine light to flicker, and only a certified professional can get to the core issue if it is not what you were thinking.

2. The car is not starting

As mentioned above, spark plugs help the car to start. Therefore, if you notice your car is having trouble while starting, it means it requires a spark plug replacement!

Worn-out and old spark plugs can cause your car engine to have a difficult time while starting. So, if your car is not starting in one go, it is better to get it checked and replaced by a mechanic as soon as possible. Other reasons, other than worn-out spark plugs that could stop your car from starting smoothly can be battery issues, burst spark plug wires, etc.

3. The fuel runs out too quickly

A definite sign that your car needs a spark plug replacement is that you are running out of fuel all the time! If you find yourself filling the fuel tank too often, then it’s a sign that your spark plug is worn out.

When spark plugs lose their ability to function properly, they start relying on the car’s gas mileage. This can lead to increased fuel consumption as the engine won’t be burning the fuel to its full capacity. 

4. The acceleration isn’t working

If you push the accelerator pedal, and your car does not speed up according to the push, then it points towards a problem in the spark plug. Driving a car with a worn-out spark plug can ultimately lead to a slow accelerating car, as there won’t be that much juice to boost the car due to low sparks. 

No one likes driving a car that can’t speed up when you need it to, so do get that spark plug replacement to get your car back to normal performance.

5. The car manufacturer’s schedule says it’s the time

The most ideal way of knowing whether your car needs a spark plug replacement or not is to follow the car manufacturer’s schedule.

You can find this information in the maintenance schedule given by the manufacturer, which will give you the exact time when you need to get your car checked and components replaced or repaired before they start causing problems. Usually, it’s always near 80,000 miles on the maintenance schedule. However, if you notice any of these problems earlier on than the given miles, then you should get your car checked immediately to have an optimized engine performance.

If you have a damaged or old spark plug and continue to drive the car with it, your engine will likely be negatively impacted and may break down. This will increase your fixing costs and will require more maintenance, or at worst, lead you to a horrible accident.

Benefits of Replacing Spark Plugs

There are many reasons why you should often change the spark plugs, and replace them with new ones for better efficiency of the engine. Just like any machine, a new part adds to the overall productivity and gives you better results than before.

Here are some benefits of replacing spark plugs;

  • New spark plugs will operate at their best and increase your car’s overall performance, and also contribute to a better, greener environment with fewer emissions in the air.
  • Replacing spark plugs can be cost-effective and helps you save a lot of money in the future like maintenance of other’s parts such as the engine and combustion. 
  • You won’t be wasting money on refueling your tank again and again.
  • You won’t have to face abrupt breakdowns of the car and be stuck on the road waiting for a towing service to rescue you. 
  • Your car will drive better, quicker, and move at a smoother pace without interruptions.
  • Your car’s motor function will be optimized as the spark plug will produce electricity at a great level, and make the combustion, engine, and car’s acceleration more responsive and consistent. 

Where to get Spark Plugs?

You can get Spark Plugs from many places throughout the United States. You can buy them from stores physically, or order online from e-commerce sites such as Walmart and Amazon. They offer spark plugs from multiple manufacturing companies and deliver them right to your doorstep, which can save you a lot of time and money.

Other websites you can look at are the Radio Show and Denso that also sell spark plugs online. 


Spark plugs are a valuable component of the car’s engine and are important to change when it’s time. A worn-out or damaged spark plug can do no one any good, and like any illness that needs treatment, your car requires maintenance too.

While driving your car, always keep in mind the signs that tell you that your spark plug needs a check. This can help you understand how often to change spark plugs in your car and keep tabs on its functions. The best part is that ordering a spark plug isn’t difficult anymore and it’s available at many places online if you need a replacement. 

Good luck!

Recent Posts