best spark plugs review

A major responsibility that comes with car ownership is ensuring that the engine is properly maintained. One of the best ways is by making sure that it turns up on a regular basis. This involves checking and possible replacement of spark plugs. The best Spark plugs are among the most crucial elements of engine maintenance, yet many drivers may be completely unaware.

best spark plugs review

To many drivers, the roaring power of a car’s engine results from explosive combustion that churns pistons in their cylinders. However, it starts with a little spark. Spark plugs initiate the ignition of air and fuel mixture in the engine. It delivers an electric current from the car’s ignition system to the combustion chamber.

Having some old, worn, and dirty spark plugs reduce your engine’s performance capacity. This is why constantly checking on the plugs and replacing them with the best spark plugs is prudent. They ensure that the engine runs smoother, cleaner, and most importantly, utilizes less fuel. Therefore, it is important that you always make sure that you replace the plugs at the first sign of trouble. This will save you money and many associated car problems.

Products Snapshot:

Product NamePrice
Autolite 104 Copper Resistor Spark Plug Check Price
Denso PK20TT Platinum Spark PlugCheck Price
Champion Copper Plus 438 Spark PlugCheck Price
Bosch Platinum +4 FGR7DQP Spark PlugCheck Price
Denso SK20R11 Iridium Spark PlugCheck Price
ACDelco Professional Iridium Spark PlugCheck Price
Autolite APP5224 Double Platinum Spark PlugCheck Price
NGK BKR5EIX – 11 Iridium IX Spark PlugCheck Price
VPlus 4pcs Iridium Spark PlugCheck Price
NGK CR9EK Standard Spark PlugCheck Price

Why Worry About Spark Plugs?

Having high-quality spark plugs in your car ensures that your engine remains a top performer and efficient. The best spark plugs take the already high-performance engine to the next level. Without proper plugs, your car experiences misfiring. Besides, you will notice your car becoming less fuel-efficient and problems with exhaust emissions.

Avoid these problems and potentially save your engine from enduring the associated damage by finding the best spark plugs in the market. The spark you need may be different depending on the type of vehicle and engine you have. This is why we have outlined a buying guide to ease your search process.

Related: How often to change the spark plug

Best Spark Plugs Review

Armed with the qualities of a spark plug to purchase, consider the following top products.

1. Autolite 104 Copper Resistor Spark Plug – Best Plug for the Price

spark plugs

Buy on Amazon

Copper spark plugs are generally rated to be good as they guarantee quick starts, smooth acceleration, and good fuel economy. The Autolite 104 Copper Resistor Spark Plug is the industry standard. The plug comes with all you need for a well-running engine, initiated by spark plug ignition.

The full platinum tip ascertains that there is no gap for erosion. This indirectly translates to a longer plug life. It is also Yttrium enhanced with a high nickel alloy as the side electrode. The alloy maintains a precise gap, further increasing the plug’s life.

Necked down center electrode of the Autolite 104 Copper Resistor Spark Plug fires quickly and cleaner. It also requires less voltage for easier starts, improved fuel economy, and quicker acceleration. The plug features a platinum alloy pad on the ground electrode for extended durability. Finally, yet importantly, the nickel-plated steel shell is corrosion resistant ascertaining longer life.


  • Full copper core for better performance
  • One-piece terminal adds strength
  • Multi-rib insulator reduces flashing-over danger
  • Good plug for the price


  • Copper doesn’t last long

2. Denso PK20TT Platinum Spark Plug – Best Two-Tip Spark Plug

spark plugs

Buy on Amazon

Platinum spark plugs are considered the best despite their expensive nature. Perhaps their durability is something that makes car owners turn a blind eye to their price tag. For sure, you will go more than 100 miles after the proper installation of a platinum plug. Quite irresistible.

The Denso PK20TT Platinum Spark Plug is an all-around plug, perhaps what your car needs. Its two-tip technology features 11mm platinum in the center electrodes and an enhanced 11mm titanium ground electrode.

Besides longevity, Denso PK20TT Platinum Spark Plug provides improved fuel economy, faster starts, and better acceleration compared to other single platinum plugs. For better insulation, Denso preferred to use purified alumina powder. Certainly, it provides exceptional dielectric strength as well as smooth thermal conductivity allowing the plug to withstand extreme stress.

Manufacturers of Denso PK20TT Platinum Spark Plug stand behind their product’s working effectiveness, providing warranties to their products not working properly. However, they warn that they do not cover issues arising from shipments, incorrect installation and damages arising from incorrect part applications. The following video shows the difference between iridium and platinum.


  • Features two-tip technology
  • Good purified alumina coating
  • Enhanced fuel economy
  • Ascertains better acceleration
  • Titanium-enhanced ground electrode
  • Better thermal conductivity
  • Lasts longer


  • Quite expensive

Related: What Are the Signs of Bad Spark Plugs?

3. Champion Copper Plus 438 Spark Plug – Best for Fuel economy

Champion Copper Plus 438 Spark Plug

Buy on Amazon

The Champion copper plus is a very standard spark plug within the Automobile industry. Apart from that, copper spark plugs are generally favored in the industry due to their seamless performance and efficiency. The Champion copper plus also has a Yttrium coated with Nickel to further complement its longevity. The coating enhances the heat control for the electrode and offers maximum efficiency. The SAC-9 semiconductor resistor ensures great performance with better efficiency of thermal control. 

The Champion copper plus having a full copper core offers a much smoother acceleration experience for the user. As mentioned previously the nickel alloy provides a precise gap for the electrode as well. The Copper plus 438 while being a full copper core spark plug has a ribbed tip that resists erosion by a lot.

The customers have repeatedly mentioned that the Copper plus 438 is a great value for money and also improves fuel economy. The use of high-quality copper core electrodes greatly complements its performance for prolonged usage as well. However, it is necessary to note how prolonged usage might often result in erosion of the copper core. The TinTac and Ultraseal Shells help to cover such erosion issues.

The corrosion resistance of the spark plug is also a major feature and adds to its already impressive durability. The double tip technology allows the spark plug to be used in a variety of engine models. The copper core electrode ensures better heat control which helps to draw the best performance out of the engine.


  • Copper plus 438 has a full copper core electrode. 
  • High EMI and RFI suppression with the use of a SAC-9 semiconductor.
  • TinTac and Ultraseal Shells prevent corrosion.
  • The ISO and SAE certifications further testify to its durability.


  • Falls short on prolonged usage.
  • The copper core is susceptible to erosion

4. Bosch Platinum +4 FGR7DQP Spark Plug – Best Performing Spark Plug

spark plugs

Buy on Amazon

Bosch, without a doubt, is well known for its wide variety of automotive exterior accessories such as wiper blades and engine products like oil filters and spark plugs. The Bosch Platinum +4 FGR7DQP Spark Plug is made to be a unique model compared to other ordinary plugs.

The highlight of this plug is the factory-set electrode gap for easy installation. Upon purchase, you will never need to adjust anything making the process effortless. As if not enough, the plug provides four yttrium-enhanced ground electrodes instead of the standard single electrode. This provides optimum access to the air and fuel mixture, for the most efficient combustion.

Like other Bosch products, it features surface air-gap technology that provides the most powerful spark for ultimate engine performance. The yttrium alloy reduces the gap wear and oxidation ascertaining an extended optimal performance.

To assure customers of the effectiveness of their products, Bosch provides a warranty to its products from defects in material or workmanship. The warranty period starts the day the product is delivered. However, like other warranty covers, it doesn’t cover labor costs in diagnosing the defects, removal, and reinstallation.


  • Ease of installation
  • Durable and longer lifespan
  • Warranty
  • Improves engine performance


  • Takes a long time for the warranty to be provided

5. Denso SK20R11 Iridium Spark Plug – Best Longer Lasting Plug

spark plugs

Buy on Amazon

Denso is undoubtedly better known for its spark plugs out in the market. Their quality and effectiveness are outstanding. Yet another model in the market is the Denso SK20R11 Iridium Spark Plug. Like the predecessor products, this comes with better and enhanced features for great overall engine performance.

Some of the notable features of the Denso SK20R11 Iridium Spark Plug include:

  • Denso patented 360 degrees welding process, which ensures exceptional quality bond and overall structural strength of the iridium center electrode.
  • Denso patented and optimized iridium and rhodium alloy, which is probably the highest concentration for greater durability.
  • Machine rolled threads which prevent seizing and possible cross threading during installation or removal.
  • 100 percent pre-fired spark plugs to ensure the highest quality possible.
  • Copper-glass seal bonds at the center electrodes and an insulating glass tight seal.
  • Purified alumina powder provides exceptional strength and thermal conductivity.
  • Five rib insulators that prevent flashover


  • Excellent performance and engine acceleration
  • Stable combustion during idling
  • Long spark plug life
  • Has iridium with a high melting point
  • Highly reliable
  • Warranty


  • Quite expensive

Related: Denso #3324 Iridium LONG LIFE Spark Plug Review

6. ACDelco Professional Iridium Spark Plug – Best for Engine Stability and Performance

spark plugs

Buy on Amazon

ACDelco is a premier brand, better known for GM original equipment automotive replacement parts as well as premium aftermarket parts for a wide myriad of vehicles currently. Among their best products when it comes to spark plugs is the ACDelco Professional Iridium Spark Plug. Yet another iridium spark plug, expect nothing but the best from this plug.

Before thinking of replacing your plug, ACDelco advice that you observe for the following signs of wear.

  • Trouble with engine starting by hesitating or cutting out
  • Lack of acceleration power uphill
  • Cranks in upper and lower portion of the spark plug insulator
  • Chipped or broken insulator tips
  • Damaged spark plug boots
  • Sluggish engine performance among other signs.

If your car has one of the signs mentioned above, it could be the best time to get the ACDelco Professional Iridium Spark Plug. Being an iridium made plug, it offers great engine stability and smooth performance.

Iridium spark plugs have small and efficient electrode designs making them reliable for cold starting and quick acceleration. The iridium fine-wired electrode helps in burning away carbon deposits as they form. It also features a seal, which helps in blocking radio frequencies that may affect the vehicle’s electronic.


  • Iridium made – durability
  • Excellent engine stability
  • Smooth performance
  • Good for the price


  • Daunting installation process

7. Autolite APP5224 Double Platinum Spark Plug – Best for Durability

Best Spark Plugs

Buy on Amazon

The Autolite APP5224 Double Platinum Spark Plug is yet another spark plug with undoubtable durability compared to the ordinary copper core, single-plated platinum and even iridium. Unlike the single platted platinum, this spark plug features a platinum-coated core, platinum electrode and platinum conductor arch.

This results in quicker sparks, quicker acceleration, better or rather conservative fuel consumption and easy startups. The full platinum tips ascertain that there is virtually no gap erosion. It also works to optimize your engine’s performance for better fuel economy and longer life.

The center electrode of Autolite APP5224 Double Platinum Spark Plug is necked down thus firing quickly and cleaner. It also requires less voltage to start and provides quick acceleration.

The spark plug are designed to eliminate gap erosion, increase the durability of the plug and reduces misfires. The lifespan of this spark plug lasts anywhere between 40 and 80 thousand miles.

To ascertain the quality of their products, Autolite provides a warranty, which covers the parts of the spark plug. The warranty extends for one year. Of course, terms and conditions apply like other covers.


  • Longer lasting spark plug
  • Made of high-quality
  • Full platinum tip ensures no gap erosion
  • Better performance due to the full copper electrodes
  • Nickel alloy side maintains precise gap
  • Improves fuel economy


  • Challenging installation

8. NGK BKR5EIX – 11 Iridium IX Spark Plug – Best Performance Spark Plug

Top spark plugs

Buy on Amazon

There is no guesswork when it comes to car spark plugs. It either fits or doesn’t fit. The NGK BKR5EIX – 11 Iridium IX Spark Plug is designed to specifically fit performance aficionados. This spark plug comes with great ignitability, superior anti-fouling, and improved throttle response.

As mentioned before, the thinner the diameter of the center electrode, the low the voltage. This model has a 0.6mm laser-welded fine iridium tip. This ensures high durability and a consistently stable spark. The tapered ground electrode minimizes the presence of electrical quenching effect in the engine.

An additional benefit that accompanies this spark plug is the longer insulator nose that prevents fouling. It also features corrugated ribs fitted on the insulator that prevents flashover and a triple gasket seal that eliminates risks of combustion gas leakage.

Being an iridium best spark plug, expect a product with a high melting point. This gives it durability and prevents easy electrical wear, making it a perfect choice for high-performance engines. It can handle all the heat abuse without giving up. Most importantly, the trivalent metal plating comes with superior anti-corrosion and ant-seizing properties.


  • Extreme ignitability
  • Superior anti-fouling
  • Highly durable
  • Corrosion resistant
  • Minimal combustion gas leakage
  • Good for high-performance engines
  • Warranty on parts


  • Quite expensive

9. VPlus 4pcs Iridium Spark Plug – Best Spark Plug For Wide Heat Range

vplus spark plug

Buy on Amazon

VPlus Iridium being an iridium spark plug is generally an expensive choice. However, the durability it offers is often the best in class and makes its prices appear much more reasonable. The VPlus Iridium is a popular choice due to its all-around functionality. The Iridium insulation also helps in improving the acceleration to be a smoother one. Due to the perfect optimization of the insulator, the performance of the engine is sustained during instances of prolonged usage.

Due to the use of purified Alumina powder the spark plug can withstand high thermal conditions while providing extensive dielectric strength. This adds to the durability of the spark plug as well. It is one of the most preferred two-tip iridium spark plugs in the automobile industry as reviewed by several customers. 

The electrode shares a coating of both iridium and titanium which makes the spark plug far more durable than any contemporary spark plug. The smoothness of the acceleration is observed upon the installation of a VPlus Iridium spark plug as well making it a customer favorite. 

Lastly, one of the most important selling factors for the spark plug will be the customer service provided by the company. The warranty which comes with the product makes it a great choice for customers who expect rough usage and maximum value. The spark plug also helps in reducing emissions and improves the fuel efficiency of the engine. The colder heat ranges it is equipped with help it to maintain performance under intense conditions.


  • VPlus Iridium possesses a ribbed insulator to avoid flashover misfires.
  • The iridium insulator enhances the heat resistance.
  • The thermal conductivity of the insulator is optimized.
  • The nickel plating on the shell helps the spark plug to resist corrosion.
  • A fine 0.6mm wire firing pin improves durability and ignition experience.


  • Being an iridium spark plug the VPlus Iridium is quite an expensive choice.
  • Iridium spark plugs are often incompatible with older engines.

10. NGK CR9EK Standard Spark Plug – Best All-Rounded Spark Plug

Best Spark Plugs for High Mileage

Buy on Amazon

NGK spark plugs are increasingly becoming popular in the market due to their outstanding features. They are perhaps among the best standard spark plugs in the market currently. The NGK CR9EK Standard Spark Plug is one of the solid copper plug with amazing features for a smooth running engine. Watch the video to know more about various types of spark plugs.

As expected, spark plugs should ensure that your car gets a greater spark, better conductivity and great heat dissipation. This is what this model brings along. It also has a long insulator nose that prevents any possible fouling. The corrugated ribs fitted on the insulator prevent flashover as the dual ground conductors ascertain consistent spark.

Gas leakage is taken care of by the triple gasket seal. For durability and longer use, the NGK CR9EK Standard Spark Plug has zinc-dipped shell.


  • Higher heat dissipation
  • A longer nose prevents fouling
  • Ground electrodes provide a consistent spark
  • Minimal gas leakage
  • Warranty


  • Requires careful installation

Check also:

How does a spark plug work?

Buyer’s Guide

Size of the Electrode Gap

When it comes to spark plugs, the “one size fits it all” narrative doesn’t work. The best electrode gap for the spark plug depends on your car. This is why it is important to understand how the gap size of the car’s electrode affects performance. The larger the gap of the electrode, the higher the voltage required to provide the spark.

Large gapped electrodes with high voltage requirements are old. New model vehicles are overly efficient and produce the same results even at a lower voltage. Therefore, you’ll need an electrode with a smaller gap between electrodes.

Spark Plug Materials

Spark plugs are primarily made of four materials, classified by the conductive material sitting in its core. They include copper, iridium, platinum, and double platinum plugs. Sparks resulting from spark plugs jump from the sharpest point on the center electrode to the sharpest point on the side electrode. Therefore, when choosing a spark plug, find one that retains its shape for long miles.

Platinum and iridium are relatively harder and have higher melting points thus last compared to copper plugs. Also, small diameter electrodes proportionally require low voltage to start the spark. That said, iridium plugs are considered the best, followed by platinum with copper being the last.

Nonetheless, these materials are often combined and used together. For instance, iridium plugs are often paired with platinum as platinum are paired with copper materials. Keep in mind that some vehicles are strictly designed to use copper spark plugs.

Copper plugs are the most inexpensive, going for less than $3. However, with such a price tag, don’t expect the best performance. They typically last for about 20,000 to 40,000 miles before needing replacement. The center rode of the copper spark plug is 2.5mm in diameter. It is the largest of all and takes more voltage to work. Copper plugs wear out quickly as the nickel alloy used in the firing end is soft and easy to wear out.

Platinum spark plugs are the direct opposite of copper plugs. Worst performance but the best for longevity. They operate at low temperatures and last much longer. On the other hand, double platinum spark plugs are amped-up versions of the single plated platinum spark plugs. They have a longer lifespan and improved performance over iridium and regular platinum spark plugs.

Iridium spark plugs are made of less conductive materials compared to copper, but harder than platinum or copper. This makes them a top choice, and perhaps most expensive. They provide decent performance with much longevity. Due to their expensive nature, manufacturers reduce the diameter of the center electrode to around 0.4mm. This actually increases the firing efficiency. They are best for vehicles with coil-on-plug ignition systems.

Spark plugs insulation

All spark plug types have ceramic insulations to protect the spark plug from the heat of electricity. However, the amount of insulation protecting the electrodes determines whether your spark plugs are “hotplugs” or “cold plugs.”

Hotplugs have less insulation and allow the ignition to burn hotter. This burn tends to remove the carbon buildup around the spark plug during ignition. High-performance cars recommend the use of cold plugs. This is because these cars have engines running at exceedingly high temperatures. Therefore, the use of hotplugs would increase the temperatures further resulting in engine damage.

best spark plug for high mileage & performance

Type of Car

Even with the different qualities above, they could only be relevant if they are designed for your type of vehicle. Note that cars have different grades of spark plugs than trucks, which use different plugs than SUVs.

Motorcycles also have their own kind of plugs, so as ATVs. Therefore, understanding what type of spark plug your vehicle requires is overly important as understanding the quality of the spark plug itself.

Final Verdict

Hopefully, this buying guide and Best Spark Plugs for High Mileage reviews help you to find the best plug suiting your personal needs and preferences. Cars are among the few assets many people take pride in. Ensuring that the best products are fitted should therefore be a responsibility.

Poor-quality plugs have their own shortcomings. In addition to using the best spark plugs, carbon buildup is a common problem. Therefore, use a high-quality fuel injector to prevent this build-up. Octane boosters will also help to make the fuel burn slower.

Frequently asked questions of Spark Plugs

  1. What is a spark plug?

A spark plug is a metal rod that is used in the internal combustion engine in the vehicle’s engine. The spark plug creates a spark to ignite the air-fuel in the engine.

  1. How big is a spark plug, and how many does a car require?

One spark plug is the size of the pointed finger. They are present only in cars with internal combustion engines. The cars will get one spark plug per cylinder. If the vehicle has four-cylinder combustion engine, then it will have 4 spark plugs.

  1. What is the function of the spark plug?

The spark plug supplies a small electrical spark. This spark ignites the fuel within the combustion chamber at the right moment and pushes the cylinder down to get the car moving forward. They are vital components that operate the engine and the other parts in the combustion chamber of the vehicle.

  1. What is the cost of the spark plugs?

Spark plugs are generally sold in sets and their cost range from $16 to $100. The cost of these plugs depends on their brand and the material they are made of.

  1. What is a fouled spark plug:

A fouled spark plug is one that has its insulator nose coated with a foreign substance such as carbon or oil. If a spark plug is not working up to its efficiency, it is considered to be fouled.

  1. Why do the spark plugs wear out easily?

Generally, the spark plugs wear out when the carbon, the leftover of combustion, builds over its electrode and causes the spark to misfire. Other reasons why this unit wears out easily are driving at low speeds for a long duration, inefficient combustion due to a mixture of air and fuel, dirty fuel injectors, idling the vehicle for a long time, etc.

  1. When should I change my engine’s spark plug?

If your car displays issues such as trouble starting, low fuel mileage, slow acceleration, rough idling, etc., then it is an indication that you have to change the spark plug of the engine immediately. However, it is a best practice to change the spark plug of the engine when the vehicle crosses 30,000 to 90,000 miles in mileage.

  1. Will my car run faster if I change the spark plug?

Spark plugs actually improve the fuel economy of the vehicle and get the engine to run at its peak without any stalls, knocks, or pings.

  1. Are Iridium spark plugs better than other types of spark plugs?

The efficiency of the spark plugs depends on their quality. Iridium spark plugs are known to last 25% longer than ones made of platinum.

  1. How much does it cost to replace the spark plugs?

The cost of replacing the spark plug depends on the size of the car engine and the credibility of the service center. It might cost anywhere between $75 and $250 depending on the service center.

Previous article13 Best Baby Swing for Reflux & Small Spaces in 2024
Next article10 Best Weed Eater in 2024 (Commercial & Gas powered String Trimmers)
Lara Herrington
With over 12 years of experience, she is a proficient content writer and editor specializing in a diverse range of subjects, including technology news, country news, arts, science, travel, and automobiles.


  1. Thank you so much, I find the info quite helpful. I needed information on the right plugs for my Suzuki V6 escudo. thank you once again, Pearson


Please enter your comment!
Please enter your name here