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The Best Spark Plugs 2021

Spark Plugs

Spark plugs are an essential component of any gasoline engine as they provide an electrical current from the ignition system to the combustion chamber. It ignites the fuel and air mixture, which provides the internal combustion required.

The best spark plugs are the NGK 2667 BKR7EIX, which are designed for those wanting maximum performance from an iridium spark plug.

The health of the spark plug is linked to the performance of the engine and as shown in the image above, they can become damaged easily. They are a cheap and easy to replace service item that can a huge difference to the performance of your car.

Table of Contents

Best Spark Plugs

Spark PlugsTypeSpeciality
NGK 2667 BKR7EIXIridiumPerformance
E3.36 PowersportsNickel/CopperHorsepower
NGK 7090 BKR5EGPPlatinumGas Mileage
Denso K16TR11CopperAffordability
Bosch 6702PlatinumLong Service Life

There are three main types of spark plug that are installed in your engine. These include copper, platinum and iridium but you should always check the type of spark plugs that your engine requires, which can be found in your vehicles owner manual. Of course, if you have a diesel engine you will require glow plugs for the inital startup as diesels work from compression rather than a spark.

Standard spark plugs will be able to last between 10,000 to 20,000 miles but the premium platinum and iridium types can handle many more miles. Below is a list of the best spark plugs that will restore lost horsepower and fuel efficiency.

NGK 2667 BKR7EIX Performance Spark Plugs

NGK spark plugs are one of the most popular brands worldwide and they produce a variety of plugs suited for affordability, fuel economy and performance. The NGK 2667 BKR7EIX are designed for performance enthusiasts who require a stronger spark.

Features of the NGK 2667 BKR7EIX include:

  • 0.6mm laser welded fine iridium tip
  • Longer insulator nose to prevent fouling
  • Tapered ground electrode
  • Corrugated ribs on insulated
  • Triple gasket seal eliminates leakage

As it uses iridium, these NGK spark plugs provide a much better spark for improved throttle response and superior anti-fouling properties. Overall, they are the best performance spark plugs and are backed by the reputable NGK brand.

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E3 Powersports Spark Plug

For those that are wanting to improve their horsepower in anyway possible, these E3 spark plugs are designed to bring out the best from your engine. This is made possible by creating a superior spark compared to cheaper alternatives.

In terms of the features of the E3 Powersports Spark Plugs, they include:

  • Sharp electrode edges
  • DiamondFire electrode technology
  • Produces a rapid spark discharge
  • Center electrode is created from nickel alloy with a copper center core

Overall, the E3 Powersports are the best spark plugs for horsepower and are proven to provide significant power increase between 6 to 12%. However, it is not just the power that increases because so does the fuel efficiency and emissions.

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NGK 7090 BKR5EGP G-Power Spark Plugs

Another popular NGK spark plug is the 7090 BKR5EGP G-Power, which is designed for gas mileage and power (hence G-power).

In terms of the features of the NGK 7090 BKR5EGP G-Power, they include:

  • Platinum alloy ground and center electrode
  • 0.6mm laser welded fine platinum tip
  • Triple gasket seal to prevent any gas leakages
  • Trivalent metal plating for anti corrosion and seizing properties

Compared to the iridium alternative, these NGK spark plugs that use platinum instead are more than half the cost. On top of this, they are designed for fuel efficiency instead of performance. Overall, the NGK 7090 BKR5EGP G-Power are the best spark plugs for gas mileage and are produced by the reputable NGK brand.

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Denso (3194) K16TR11 Copper Spark Plug

Denso is just as popular as the NGK brand and they produce a variety of different types of spark plugs. The K16TR11 is a direct OEM replacement that uses a copper core for better thermal conductivity.

Features of the Denso (3194) K16TR11 Copper Spark Plugs include:

  • Machine rolled threads to reduce cross threading and seizing
  • Uses 5 ribs to prevent flashover
  • Purified alumina powder insulator construction
  • Dual ground electrodes

Overall, they are great all round spark plugs that are direct OEM replacements with the backing of the reputable Denso brand. They are also fairly cheap compared to the alternatives but the copper core means they will have to be replaced sooner.

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Bosch 6702 Platinum Spark Plug

Bosch is another well renowned brand and within the automotive industry, they are known for their ignition components such as spark plugs, distributors and more. The 6702 are platinum spark plugs that Bosch claim provide twice the length of service life compared to standard copper plugs.

Features of the Bosch 6702 spark plug include:

  • OEM replacement
  • 360 degrees laser welding
  • Fine wire design for performance
  • 4 year performance guarantee
  • Ribbed insulator design
  • Pre-gapped for optimum fit

Overall, these Bosch spark plugs are excellent OEM replacements that provide a longer service life compared with most alternatives. You also have peace of mind that they are built to the highest of standards with a 4 year performance guarantee.

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Spark Plugs Buying Guide

Spark plugs are an essential component that ignites the air and fuel mixture within the combustion chamber. Without a spark, the car will not start but of course. Some vehicles will require a superior spark in order to ignite the mixture, so its important that you choose the correct spark plug for your vehicle.

Some engines may even require two spark plugs for each cylinder. For example, when serving my very own 1999 Mercedes E55 AMG, it has 8 cylinders (V8) where each cylinder required two sparks. Although they are a relatively cheap service item, the prices do add up for larger engines. Therefore its worthwhile spending time to research various plugs that are suited towards your vehicle or offer additional benefits such as performance or gas mileage.

Below we have compiled a detailed buying guide to help you understand everything that you need to know regarding spark plugs in order to make an informed purchase.

Performance Spark Plugs

How Do They Work?

The spark plug is threaded into the cylinder head of the engine where a spark plug wire or ignition coil is mounted to the terminal side of the plug. The electrode tip then sits inside of the combustion chambers and is what produces the spark.

In terms of producing the spark, the ignition system provides a precisely controlled electrical current with specific timing. This flow through the various components and through to the plug, which then produces the spark that ignites the air and fuel mixture required for a fully functioning engine.

If the engine is suffering from ignition issues, you can use a timing light to diagnose and fine tune the spark.

Copper vs Platinum vs Iridium

You will notice that we listed copper, platinum and iridium spark plug options within this article. The purpose of the metal in a spark plug is to transfer the electrical current from the ignition system to the plug in order to form the spark. Therefore, it is a fairly important part of the spark plug and its performance.

Copper Spark Plugs

Copper plugs are one of the cheapest available and are mostly used as an OEM part. However, the service life of copper plugs can be far less compared with the like of iridium and platinum spark plugs. Copper is however the best conductor, which means they are great for race cars but you will be changing them far more often.

Platinum and Iridium Plugs

You will often find that manufacturers of modern cars are turning to platinum or iridium tips due to their increased service life. This is because unlike the copper alternative, they do not have rapid erosion when subjected to adverse conditions.

When comparing between platinum and iridium, the latter tends to be the more expensive but offer both excellent performance and longevity. Platinum on the other hand offers long service life and gas mileage but lacks in terms of performance.

What Type To Choose?

In terms of which type of spark plug tip is best for your car, it really depends on your requirements. To conclude:

  • Copper = Excellent performance but worst longevity
  • Platinum = Excellent gas mileage and service life but worst performance
  • Iridium = Excellent performance and excellent performance but expensive

How Often To Change Spark Plugs?

As with any automotive service part, there will be a certain lifespan on every spark plug. Some engines will require the plugs to be changed more often than others for example, a performance car such as Lamborghini will require far frequent changes compared to a Honda.

On average, most manufacturers of the average car will state every 20,000 to 30,000 miles but this will differ. The best place to find when they need to be changed will be within your owners manual. You can also perform a visual inspection of the spark plugs and check for any fouling of the plugs or other defects.

It is recommended that you replace the fuel filter, car air filter and use synthetic motor oil when changing your spark plugs. This will help your vehicle run much more smoothly.

Spark Plugs For Gas Mileage

When To Replace Your Spark Plugs

Deciding upon when to change your spark plugs can depend on a range of symptoms. However, if you are running a modified engine where you have added a turbocharger or used a flash programmer, you may require a stronger spark from your plugs.

If you notice any of the following symptoms, you may require new plugs:

  • Difficulty starting the engine
  • Slow acceleration
  • Poor gas mileage
  • Misfiring
  • Fouled tips
  • Cracks or corrosion
  • Rough idling
  • Engine management light

A visual inspection of the spark plugs is the best method to see if you require new spark plugs. However, if you install new spark plugs and they are fouling within a few miles, this may be an indication of different engine issues.

How To Change Spark Plugs

Changing your spark plugs is relatively straight forward but you need patience as you will not want to crack the spark plug inside the engine. This can cause serious issues that will result in an expensive repair. In order to replace your spark plugs, follow these steps:

  1. Remove the coil packs or spark plug wire from the terminals.
  2. Remove any debris around the spark plug tubes.
  3. Use a spark plug socket to loosen and pull the plug straight out.
  4. Reinstall new spark plug and use a torque wrench for tightening.
  5. Connect the coil packs or wires back to the plugs

Clearing any loose dirt or debris (step 2) is often forgotten by those in a rush. However, it is very important that you do not miss this step as the dirt can easily fall into the cylinder, which can cause issues inside the combustion chamber.


Spark plugs are a critical part of any gasoline engine and without them, you will not be able to start your vehicle. In terms of the best spark plug brand is NGK and they produce a wide variety of plugs for certain applications. The best NGK spark plugs are the 2667 BKR7EIX but of course, if you do not require the additional performance, you may opt for a platinum alternative for longevity and gas mileage.

All of our recommendations cover a range of different types of plugs but you must ensure they are suitable for your vehicle. If you choose the wrong plugs, your engine may not perform as expected with reduce fuel economy and performance.

procarreviews author

Written By Dan

About the Author

Dan is an automotive journalist and owner of over 10 cars ranging from supercars, tuned cars, classics and your good old beater cars. He always likes to get his hands dirty with nut and bolt restorations or detailing sessions using the best products on the market.

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