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The engine in your car, truck, or crossover operates on the simple principle of capturing the energy from countless tiny explosions created when a mixture of gasoline and air is ignited inside of its cylinders. Deep inside of your engine, fuel and air are drawn in and compressed by the pistons before being ignited many times per second. This creates an energy-dense explosion whose power is used to drive the vehicle.

The lowly spark plug is responsible for trigging this explosion when an electrical current flows between its center electrode and ground electrode, creating a tiny spark. Though small, inexpensive and often overlooked, the spark plug is one of your engine’s most vital components.

Like most parts of a vehicle, spark plugs need occasional attention — most often via the removal of old and worn-out plugs and replacement with fresh new ones. Spark plugs wear down and wear out over time, and when they do they’ll reduce your vehicle’s fuel economy, cause its performance to suffer, and may even cause damage to other engine parts.

As such, replacing your spark plugs is an important part of keeping your engine ticking in tip-top shape, the way the factory intended. After all: if your spark plugs are worn, dirty, or past-due for a change,  they can’t do their job effectively, and your engine’s performance suffers for it.

Below, we’ll look at some common and highly rated spark plug options, everything you need to know about them, and a list of the top spark plugs available. We’ll start with the best spark plugs, but if you want to learn more about them, use the table of contents to navigate.

1. Editor's Pick: Denso Platinum TT Plug

denso platinum tt spark plug

Combining advanced technologies, improved efficiency and performance, and the reputation of one of the biggest names in spark plugs, the Denso Platinum TT spark plug range is one of the best-selling spark plugs available. With an alumina powder insulator and platinum construction, Denso Platinum TT plugs turn in consistent performance across a long lifespan. Also featured is a titanium-enhanced ground electrode for longer life. Further, Denso is one of the world’s largest manufacturers of original-equipment spark plugs and are noted for high levels of quality control.

This spark plug family is available to fit a wide range of modern vehicles while meeting or exceeding factory requirements. Owner reviews often suggest that these plugs restore mileage and performance, and numerous owners note smoother operation and a smother idle, too.

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2. NGK V-Power Spark Plug

ngk v-power spark plug

With over 8 decades of experience, NGK is one of the biggest names in spark plugs. Years of experience creating specialized sensors, connectors and other car engine components have helped earn NGK a reputation as a trusted brand noted for quality and consistency. Their V-Power spark plugs feature a unique electrode design with a built-in notch, which creates a unique spark shape that helps improve mileage and performance while contributing to cleaner, longer-lasting electrode surfaces.

The V-Power plugs also feature NGK’s Trivalent Metal Plating technology to help resist corrosion and provide superior anti-seizing characteristics—making them a great pick for the do-it-yourselfer. Affordable pricing and a variety of fitments for many cars, trucks, motorcycles and power equipment applications means it’s easy to find the right set for your needs.

Notably, NGK’s V-Power spark plugs offer greater ignitability from less system voltage—meaning more power and efficiency, and reduced strain on other ignition system components. A long list of stellar owner reviews suggests that these plugs are the way to go, and well worth their slight pricing premium for confidence, proper fitment, and overall performance and satisfaction.

3. ACDelco Professional Iridium

acdelco professional iridium spark plug

From ACDelco comes the Professional Iridium Spark Plug line. Featuring the latest technology available, these plugs are designed for very long life, stable idle, smooth performance and maximum efficiency—all while meeting or exceeding factory specifications for quality and durability.

ACDelco is one of the most recognized names in auto parts, and the Professional Iridium plugs are an ideal replacement for most modern vehicles. The iridium components allow for use of a smaller and more efficient electrode, which helps with cold engine startup. With reduced voltage draw on the ignition system, these plugs can even help keep your engine running better, for longer.

More new vehicles than ever are using iridium spark plugs, and ACDelco Professional Iridium spark plugs put the technology to work for you. These plugs also feature a built-in suppressor to help block radio frequency interference which can affect vehicle electronics. These plugs are also easy to use as they come pre-gapped from the factory, saving a step for do-it-yourselfers. Many owner reviews comment positively in the quick and easy installation.

4. ACDelco Professional RAPIDFIRE

acdelco professional rapidfire spark plug

Also from ACDelco, the Professional RAPIDFIRE spark plug features affordable pricing, a wide range of applications, and a variety of unique features designed to improve performance and durability. The RAPIDFIRE spark plugs employ a rib-less insulator for a more secure fit at the sometimes-troublesome seal between the spark plug and its boot. A copper core provides greater heat transfer to help your engine run cool while prolonging the life of the plug, and a platinum center electrode tip generates a superior spark.

Designed for affordable and durable use in a wide range of engines, ACDelco’s Professional RAPIDFIRE Spark Plugs are a top spark plug pick for value-minded shoppers. These plugs also feature ACDelco’s solid-state suppressor, to reduce radio frequency interference. Reviews indicate that many shoppers are delighted with the restoration of smooth performance and improved fuel economy with the Professional RAPIDFIRE plugs installed.

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5. Champion Copper Plus

champion copper plus spark plug

From one of the oldest names in the spark-plug game, American-based Champion spark plugs are popular around the world. The Copper Plus Replacement spark plugs reflect years of experience and expertise—with highly affordable pricing, built-in corrosion resistance for long life, and a high-accuracy Copper Core Centre Electrode that enables higher control of the plug heat range for more consistent performance. These affordable plugs are built to OEM standards for maximum performance, and maintain a stable operating temperature under all engine operating conditions—meaning that they’re dependable, no matter how—or what—you drive.

Plus, with a patented SAC-9 semiconductor resistor, Champion’s Copper Plus spark plugs provide superior suppression of radio frequency interference, which can cause issues with vehicle electronics or stereo audio playback. Reviews show many satisfied owners, particularly those who drive older models and have been satisfied with restored engine power and mileage.

6. Motorcraft Spark Plugs

motorcraft spark plug

Designed specifically for your Ford to meet its factory specifications and requirements, Motorcraft spark plugs are a high-quality, original-equipment product created at the direction of the same engineers who designed and built the engines that use them. For no-nonsense installation and years of worry-free operation, Motorcraft plugs are the best choice for your Ford car or truck.

In modern engines, using factory-specified replacement plugs is typically best—and that’s just what Motorcraft spark plugs deliver. With world-class quality control at every step of the manufacturing process, these high-quality plugs are typically sold in application-specific kits, making them easy to shop for. Owner reviews  typically praise easy installation, and many indicate that the use of these plugs has remedied issues with hesitation, poor performance, or poor fuel mileage.

7. NGK Laser Platinum

ngk laser platinum spark plugs

An ideal replacement plug for numerous applications, including modern high-efficiency and high-performance engines, NGK’s high-end Laser Platinum spark plugs combine nothing less than the latest innovations for superior performance. Highly rated by customers and available for numerous applications, these are the world’s leading platinum plugs—and come with a strong reputation backed by stellar customer reviews.

With laser-welded electrode tips, enhanced durability via special anti-corrosion properties, and an OEM-approved design, NGK Laser Platinum plugs utilize high-precision construction and numerous innovations to provide one of the best spark plugs on the scene for today’s demanding engines.

The owner reviews say it all: many shoppers choose these plugs to replace their long-lasting factory-equipment NGK plugs, which often turn in 100,000-plus miles of worry-free use.

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What is a Spark Plug?

Spark Plug in Engine

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In simple terms, a spark plug is a small threaded metal component that features conductive metal components separated by an electrical insulator. The spark plug assembly has a terminal at one end, an electrode tip at the other. In between are a set of threads that allow the spark plug to be tightly installed into special openings in the engine’s cylinder head, typically, with one spark plug per cylinder. An electrical current is supplied to the spark plug, which causes a brief electrical arc, or ‘spark’, to form between the two electrodes, which sit in the cylinder. This spark ignites the air and fuel mixture within, kicking off the explosion that drives the engine.

How does a Spark Plug Work?

When a spark plug is threaded into the engine’s cylinder head, a spark plug wire or ignition coil is mounted to the terminal side of the spark plug and the electrode tip sits inside of the engine’s combustion chambers, or cylinders. The spark plug is mounted rigidly in place, and a small gasket helps to form a tight seal, ensuring that none of the pressure created by the combustion process is allowed to escape. The vehicle’s ignition system send a precisely-controlled electrical current through the spark plug, with extremely precise timing. When this current is introduced, it flows through the plug, and ‘jumps’, via a visible spark, between the electrodes in the spark plug tip.

How often to I need to Change my Spark Plugs?

A new spark plug next to an old one that needs replacing. Photo Credit: stella_photo/Shutterstock

Spark plugs have a finite lifespan that depends on numerous factors. In most modern cars, spark plugs need to be changed infrequently, perhaps every 80,000 or 100,00 miles. In certain applications or with specialty vehicles, this interval may be much shorter and some high-performing cars or custom-built performance engines may require new spark plugs more frequently. In racing engine applications, spark plugs may need to be changed almost daily.

In a conventional modern vehicle, you’ll likely only need to change the spark plugs every few years, though earlier is typically better. In any case, the answer is in your owner’s manual, which lays out the frequency with which you need to change the plugs, and the type of plug you should use. Just remember that the interval set in your owner’s manual is a maximum guideline— and you’re best to change your plugs before that point, or at the onset of any loss of performance, smoothness or fuel efficiency from your engine.

Remember that changing your spark plugs at or (ideally) before their factory service interval is extremely important. Stretching spark plug change intervals can rapidly lead to reduced performance, additional strain or damage to other ignition system components, and the rapid accumulation of gunk and soot within the engine. Plugs overdue for replacement can often lead to snowballing problems with engine durability, performance and fuel mileage—and changing them at or before their advised intervals is best.

Consider changing your air filter and fuel filter alongside your spark plugs as part of a comprehensive tune-up.

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Caring for your Spark Plugs:

Most spark plugs require no special care. These are expendable components: simply, they’re designed to work for a given service life before being discarded and replaced.

What Kind of Spark Plug Do I Need?

Spark plugs come in many shapes, sizes and variations—even if they all look similar and function in the same way. You’ll need to select spark plugs based on their physical dimensions to ensure they fit and function properly with your ride’s engine. Spark plugs are typically made for specific applications with very precise physical characteristics and heat ranges. From that basis, many spark plugs are offered with unique features based on the design of their electrodes, the materials used in their construction, and more. In fact, there are over a dozen spark plug variations, simply based on the design of their electrodes.

Which ones are right for you? In modern, non-modified engines, your best bet is to use the precise spark plug make, model and variation listed in the owner’s manual. These plugs were selected by engineers as the best for your engine’s efficiency, durability and performance, and they’ll be listed with a specific number or code you can use to search for the proper set of plugs.

If your engine is modified, purpose built, or non-factory original, you may require a unique type of spark plug that’s better suited for the application.

Other Notes:

When ordering new plugs, be sure you buy the correct number of spark plugs for your engine. Most engines have one spark plug per cylinder, though some have two.

You’ll need to make sure you’re using the same type of spark plug throughout your engine, and that you change all plugs at the same time.

Ignoring your engine’s spark plug change intervals can increase fuel consumption and emissions, reduce performance, and contribute to dirtier combustion, which can cause gunk-related problems elsewhere in the engine. Severely worn spark plugs can even disintegrate within the engine, causing pieces to break off inside of the cylinder, which can severely damage the engine.

How to Change Your Spark Plugs

In many applications, changing the spark plugs is a job best left for your favorite auto service technician or professional mechanic — though do-it-yourself enthusiasts should find the spark plug change to be a relatively easy job, depending on the type of engine.

The best way to change your spark plugs is to obtain a service manual for your specific vehicle, which outlines the exact steps to take. Those steps typically look something like this:

  1. Remove the coil packs or spark plug wires from the spark plug terminals by pulling them out of the top of the engine. In certain applications, you may need to remove a cover, clips, or some fasteners to access the coil packs or plug wires for removal.
  2. Clean the area around the spark plug tubes, perhaps using a blast of compressed air, to clear the area of any debris that could otherwise wind up inside of the engine once the old plug is removed.
  3. Using a spark plug socket, loosen each spark plug and remove it, by pulling straight up.
  4. Reinstall the new spark plugs, confirming they’re properly gapped (if required), and tightening them down to the specified torque level to ensure a snug fit.
  5. Reattach each spark plug wire or coil pack, and reinstall any covers, fasteners or clips.
  6. Repeat for each plug.

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