Categories: Replacement Parts

Best Spark Plugs 2021 – Top 5 Best Spark Plugs Reviews

Best Spark Plugs – MaintainYourRide Recommends:

NGK G-Power Platinum Spark Plugs

Introduction – Top 5 Best Spark Plugs 2021

Choosing the best spark plugs for your engine can have a profound impact on performance and efficiency.  Fouled or damaged spark plugs can cause running lean/rich, misfiring, engine knock, and even lack of power in a particular cylinder.  Any of these issues can cause the Engine Control Unit (ECU) to put the car in “limp-mode” where timing is severely retarded in order to protect the engine from further damage.

When changing your spark plugs, be sure to closely examine the combustion chamber/igniter side of each of the plugs.  This can give a great indication of the health of your engine and how efficiently the ECU acting.  Signs of Bad Spark Plugs – As shown in the infographic below, there are many different stories your plugs can tell.  If you notice severe damage such as oil on spark plug or melted/broken electrodes, we recommend you take your car to a local mechanic for immediate inspection.

Spark Plug Wear Chart

Top 5 Best Spark Plugs for 2021



NGK G-Power Platinum

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Bosch Platinum Plus 2

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DENSO Platinum TT

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ACDelco Professional Iridium

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Autolite Iridium XP

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5. Autolite Iridium XP Spark Plugs

Autolite has provided the automotive aftermarket and Original Equipment manufacturers the highest quality ignition products for over 100 years. These plugs are specifically designed for each application to meet or exceed OE quality and performance.

Autolite Iridium XP Spark Plugs have an iridium-enhanced 0.6mm fine-wire design and proprietary platinum sidewire technology, these spark plugs provide better durability and a more focused ignition for better overall ignitability and optimum performance.

Averaging over 4.5/5 stars from reviews around the web and about $5-7 per plug puts these on the high-end of the spectrum.

Buy Autolite Iridium XP Spark Plugs

4. ACDelco Professional Iridium Spark Plugs

ACDelco Professional Iridium Spark Plugs are an ideal high-quality replacement for most vehicles. They are the latest in spark plug technology and a great replacement for your vehicle’s original components.

The design features iridium coating which provides smoother idle and improved performance. The fine-wire electrode provides better ignition of the fuel which helps to burn away carbon deposits from the plug which can cause premature wear.

Slightly lower average than some of the 4.5 star options, these plugs still rate very highly and are a great choice if you’re willing to spend a bit more to gain the increased longevity of iridium technology.

Buy ACDelco Professional Iridium Spark Plugs

3. DENSO Platinum TT Spark Plugs

DENSO was a pioneer in Platinum Spark Plug Technology.
The Platinum TT originated from DENSO’s latest original equipment spark plug technology, the Super Ignition Plug (SIP). Until recently, this OE iridium Twin-Tip design could only be found in the most technologically advanced automobiles.

The TT features a Titanium-enhanced alloy ground electrode and a 1.1mm platinum center electrode. This provides enhanced flame propagation for increased engine efficiency as well as reduces quenching to generate a more powerful spark.

Over 4.5 stars from reviewers around the web, these plugs are a solid #3 option at $3-5 per plug.

Buy DENSO Platinum TT Spark Plugs

2. Bosch Platinum+2 Spark Plugs

Bosch is one of the largest manufacturers of after-market replacement automotive parts in the world. With decades of experience, they are a trusted brand with quality products and great prices.

The design features more platinum in the center electrode with two yttrium-enhanced ground electrodes which helps reduce gap wear and oxidation while providing a more powerful spark. Platinum+2 uses surface air gap technology. The spark first travels over the surface of the insulator nose and then arcs across the air gap to a ground electrode for a longer spark, without increasing the voltage requirement.

We examined hundreds of reviews and got an average of 4.8 stars. These affordable plugs are a great option if you want to save a few bucks ($2-4 per plug).

Buy Bosch Platinum Plus 2 Spark Plugs

1. NGK G-Power Platinum Spark Plugs

NGK is by far the most highly recommended brand of spark plugs by experts around the world. A large number of automotive manufacturers use NGK plugs from the factory which speaks to their reliability and performance.

NGK Spark Plugs feature a trivalent metal plating that provides superior anti-corrosion and anti-seizing properties. The Platinum coating provides great protection and durability giving these plugs a change interval of up to 60,000mi/95,000km.

These plugs have the highest rating with 4.8/5 stars over thousands of reviews from reviewers across the web. They are also extremely affordable with a price of approximately $3-5 per plug.

Buy NGK G-Power Platinum Spark Plugs

Spark Plug Replacement Near Me

Need your spark plugs changed now and don’t want to wait for shipping? Advance Auto Parts is a great local option.  Check here to see if your local store has the spark plugs you need in stock for pickup. Buy online and pickup in-store same day.

Check Advance Auto Parts Spark Plugs

When to Replace Spark Plugs

It’s best to replace spark plugs according to the manufacturer guidelines.  Depending on the type of plug, there are different recommended service lives.  Most automotive manufacturers will include spark plug replacement on the scheduled maintenance guide that is included with most cars/trucks/SUVs.  Check your user manual in the glove compartment for more information.

If you can’t find you user manual, or the spark plug lifespan is not explicitly stated, you can quickly google search the type of spark plugs that your car comes with.  From there, you can use our handy guide below to determine when to replace them and what to replace them with.

There can be extenuating circumstances that warrant early replacement of spark plugs.  If you notice your car running very rich (dark smoke from the tailpipe) or you experience a sudden loss of acceleration/power, fouled spark plugs could be the culprit.  It’s best to remove one of the plugs and check it for signs of advanced wear.  The infographic at the beginning of the article can help you determine if the plug is fouled.

*** If you do notice a fouled plug, it is important that you diagnose the cause.  Just replacing the spark plugs is a band-aid fix and will result in the same outcome – drastically reduced lifespan of the spark plugs as well as other engine components.  If you don’t feel comfortable diagnosing it, take it to a mechanic shop. ***

Choosing the Best Spark Plugs

There are a few different things that you need to consider when determining the best spark plugs for your car, truck or SUV:

First, consulting your vehicle manual to determine the manufacturer recommendation for the type of spark plugs is very important.  It may make the decision for you and drastically cut down on the amount of time  you shop around.

If the manufacturer does not recommend a specific brand or type of plug, you have significantly more flexibility in your choice.  Certain brands of plug have reputations for working better with different car manufacturers.  For instance, NGK plugs have a reputation for working very well with Japanese vehicles – Honda, Acura, Toyota, etc as well as some older American-made vehicles.  However, they don’t have quite the same reputation with European-made automobiles which tend to prefer Bosch plugs.

Heat Range

*** If you have a stock, unmodified engine, you don’t need to worry about this part. ***

The term Heat Range refers to the speed with which a plug can transfer heat from the combustion chamber to the engine head.  It has been found the optimum combustion chamber temperature for gasoline engines is between 500°C–850°C.  Within that range it is cool enough to avoid pre-ignition and plug tip overheating (which can cause engine damage), while still hot enough to burn off combustion deposits that cause fouling.

When a spark plug is referred to as a “cold plug”, it is one that transfers heat rapidly from the firing tip into the engine head, keeping the firing tip cooler.  A “hot plug” has a much slower rate of heat transfer, which keeps the firing tip hotter.

A stock, unaltered engine will run within the optimum operating temperature range straight from the manufacturer, but making modifications such as adding a turbo or supercharger, increasing compression, timing changes, use of alternate fuels, or nitrous oxide, can alter the plug tip temperature, necessitating a colder plug.

A good rule of thumb is, one Heat Range colder for every 75–100hp added.

In identical spark plug types, the difference from one full Heat Range to the next is the ability to remove 70°C to 100°C from the combustion chamber.

Iridium vs Platinum vs Copper Plugs

“Copper spark plugs” is a term mistakenly used for a standard material spark plug. A standard material spark plug traditionally uses a nickel-alloy outer material fused to a copper core. Almost all spark plugs use a copper core center to conduct the electricity, jump the gap, and promote heat dissipation.

However, as an outer electrode material, copper would not be a good choice, as it is soft and has a low melting point (resulting in a plug that would last minutes, not miles). Nearly all spark plugs, including precious metals iridium and platinum, have a copper core.

What are iridium spark plugs?  When one talks in terms of nickel alloys, platinum and iridium, one is referring to its durability, or how long a spark plug will last before it needs to be replaced. Platinum and Iridium plugs are significantly stronger and hold up longer.

Check out this Learning Center article from NGK for more information on Iridium and Laser Iridium Spark Plugs:  How Long Do Iridium Plugs Last?

Generally, Copper (Nickel-alloy) plugs ($) are standard durability (up to 40,000mi/65,000km), Platinum plugs ($$) have great durability (up to 80,000mi/130,000km), and Iridium/Laser Iridium plugs ($$$) have the best durability (up to 120,000mi/190,000km).

Maintain Your Ride Pro-Tip
Spark plug types should not be mixed. When replacing spark plugs, it is best to replace them all at once.

Maintain Your Ride Pro-Tip
Gapping your spark plugs is important for Copper (Nickel-alloy) plugs, HOWEVER, Platinum and Iridium plugs should not be gapped.  Gapping can damage the electrodes on these fine-metal plugs.

What do Spark Plugs Do?

Spark plugs are responsible for providing the ignition for the air/fuel mixture within the engine cylinders during the power stroke.  As the piston moves to the top of the cylinder, compressing the air/fuel mixture, an electrical pulse is sent through the spark plug.  A small air-gap between the conductive metals of the spark plug causes the electrical pulse to arc which ignites the air/fuel mixture, forcing the piston back down to generate power.

How to Install Spark Plugs

Installation difficulty of Spark plugs varies greatly depending on the application.  Certain cars provide very easy access to the spark plugs making the job take less than 20 minutes with basic tools.  Other cars are a bit more difficult based on things like crowded engine bays, the angle of the cylinder heads on the engine, and may even require special tools.  We recommend searching Google or YouTube for a guide specific to your Make, Model and Year.

Maintain Your Ride Pro-Tip
Removal of Spark Plugs is SIGNIFICANTLY easier if you have the right tools. A spark plug socket is a tool that should be in every MYRer’s toolbox. Check out the GearWrench 3/8″ Swivel Socket. Perfect for most applications!

Generally, there are a few basic steps that apply to all Spark Plug change jobs and some common tools that you’ll need.

Tools:  New Spark Plugs, Socket Wrench, Socket Extension, Spark Plug Socket, Anti-Seize Compound

Spark Plug Installation Guide
  1. ***Disconnect the negative battery cable***.  This is a safety precaution that should be done any time you’re working on the car’s electrical system.
  2. Locate the Spark plug tubes – These can typically be found by following the spark plug wires from the distributor cap or finding the coil packs.  Popping out the plug wires/coil packs should be fairly self explanatory. Note: Make sure you keep track of which plug wire/coil pack goes with which cylinder as reinstalling them in the wrong order can lead to engine failure.
  3. Ensure that your Spark Plug Socket and socket extension will provide enough depth to reach the spark plugs.  Extract each of the spark plugs.
  4. For the new spark plugs, use a gapping tool (if they are gappable plugs) to ensure that the gap is within spec and then apply the anti-seize compound to prevent frozen plugs.
  5. Carefully lower each plug into the spark plug tube so as not to damage the tip.  Hand tighten each of the plugs before using your torque wrench to tighten each one to spec.
  6. Reinstall the Plug Wires/Coil Packs in the proper order based on the way they were before removal.
  7. Button everything back up and give it a test drive to ensure things are running smoothly.
  8. If you see a new Maintenance Indicator Light, cut the engine off immediately and double-check your work.  You can also utilize your OBD2 Scanner to pull the MIL Codes to see what the issue is.

Can Spark Plugs be Cleaned?

Technically, they can be cleaned.  However, there is not much to gain from cleaning them.  They are constantly being combusted inside the cylinders of the engine so most of the gunk on there is going to be burned on.  With plugs as cheap as they are, there’s no reason not to just go ahead and replace the entire set if you notice some issues.

How much are Spark Plugs?

Spark plugs range in price anywhere from $2/ea to $20/ea depending on the type.  Most applications will do just fine with a nice set of Copper (Nickel/Alloy) plugs from NGK or a similar brand.  Some manufacturers recommend using iridium or platinum plugs.  These are a bit more expensive but will also buy you some extra durability.  If you can afford it, you may want to go with a Laser Iridium spark plugs just so you don’t have to worry about them for another 80-100k miles.

Spark Plugs Video


Spark plugs are one of the most important components when it comes to keeping your car running smoothly and efficiently.  They are also one of the best ways to Improve Gas Mileage on your car if they haven’t been changed out in a while.  Do yourself a favor and check yours today if you notice any decrease in performance or gas mileage.

MYR Recommended

Best Spark Plugs – Overall: NGK G-Power Platinum Spark Plugs
Best Spark Plugs – Value: Bosch Platinum+2 Spark Plugs
Best Spark Plugs – Performance: Autolite Iridium XP Spark Plugs

You might also want to consider upgrading your car battery as well.  Aging batteries sometimes provide inconsistent voltages which can adversely affect the performance of the engine and cause premature wear of the spark plugs.  The Best Car Battery Buyer’s Guide is a great resource for finding the right battery.

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