5 Best Spark Plugs (2023 Guide)

Reviewed By: Charles Noyes

A high-quality spark plug with enhanced insulation and conductivity.

A spark plug best suited for everyday driving and hotter engines.

A long-lasting spark plug that helps increase engine lifespan.

A spark pug that assists with performing consistent starts.

A spark plug that prevents engine interference with its copper core.

Although some drivers may not be aware, spark plugs are one of the most vital auto parts. Spark plug health translates to better overall performance and fuel efficiency, increasing the service life of your car. It is important, therefore, that spark plugs are regularly checked to help avoid unwanted or costly repairs.

In this article, we recommend several of the best spark plugs of various brands based on value, longevity, and more to provide you with the right fit for your vehicle. Before purchasing new spark plugs, remember to consult your vehicle's owner's manual for specifications on which ones fit your engine and safe replacement practices.

Before replacing your spark plug, it's important to purchase the proper replacement. The two things to note are spark plug material and temperature range. Try to match these features with the spark plugs that come standard with your vehicle. This information should be found in your owner's manual.

Spark plugs play a vital role in the combustion process of your vehicle's engine, and the difference between the right and wrong replacement engine spark plug can have a substantial impact on your vehicle's lifespan.

There are five general types of spark plugs:

Not only do the materials contribute to its performance, but so does plug design and fit within the engine.

The cheapest option of the five, copper, is known as the standard spark plug. These plugs have a copper centrode plated with a nickel alloy. Although relatively inexpensive, copper spark plugs are less durable than those made with other materials and need to be replaced more often.

Iridium spark plugs last longer than copper ones and require less energy to generate the spark that powers the engine. Single platinum plugs are nearly identical to copper plugs in build except for their platinum core, which provides them a much greater lifespan. Both of these options are more expensive than copper spark plugs.

Double platinum spark plugs have both platinum-lined center and ground electrodes. This makes them ideal for vehicles with wasted spark ignition systems.

The last option, silver, is weaker than iridium and platinum plugs and is generally reserved for older, high-performance vehicles.

All spark plugs have a temperature range that represents the ability to disperse heat. "Hot" spark plugs transfer heat slowly. This reduces carbon buildup and can increase spark plug longevity. "Cold" spark plugs transfer heat quickly, and are suitable for performance vehicles with fast engines. Your owner's manual should indicate the ideal spark plug heat range for your car's engine.

Every brand of spark plug has a different place where heat range is indicated, but most can be found in the part number, with lower numbers meaning a colder plug while higher numbers indicating a hotter plug. For example, the NGK Iridium IX spark plugs have the part number "LFR5AIX-11." Here, the "5" refers to the temperature range. Because these numbers are different across brands, it can be difficult to compare temperature ranges.

Most manufacturers recommend replacing your vehicle's spark plugs every 30,000.0 miles. However, modern iridium spark plugs can last up to 100,000.0 miles and longer. It is best to check your owner's manual for the specific make and model of the spark plug it has to determine its lifespan.

Telltale signs of bad spark plugs include:

A set of high-quality spark plugs may and a marginal amount of increased horsepower, somewhere between one and three percent. If anything, the right spark plugs can help keep your car at peak performance.

The cost of replacing a set is typically very inexpensive. Individual spark plugs can range from $5 to $10. Other spark plugs made from more durable materials may cost around $20, but replacing a set should cost well under $100.

NGK 7090 G-Power Platinum

NGK Iridium IX

Denso #5304 Iridium Power

HiVehicle New Iridium

ACDelco OEM 41-962

Cost

$20

$35

$25

$36

$79

Material

Single Platinum

Iridium

Iridium

Iridium

Copper

Heat Range

5

7

20

9

14

To select the spark plugs featured in this buyers guide, we consult our network of experts for their thoughts on spark plugs. These experts have over 100 years of combined experience in aftermarket auto fields ranging from detailing to accessories to tires, and everything in-between. These experts helped us identify the qualities that would be most important to someone looking for a spark plug and the standout brands in each category.

Our team then combed through dozens of resources such as DIY mechanic and auto enthusiast forums, manufacturer and spark plug-specific websites, instruction manuals from manufacturers, and reviews from online retailers. We pay particularly close attention to quality reviews and recommendations that highlight the quality of warranties, customer service support, build quality, materials, and overall reliability.

We also factored in the quantity and quality of online retailer reviews from websites such as Amazon, RealTruck, Advance Auto Parts, and more. We looked at factors such as standout customer reviews, prices, meaningful superlatives, and discount shipping eligibility. We did the research so you don't have to.

Why You Can Trust Us

Since 2020, we have published over 200 auto product reviews in an effort to make shopping for auto products easier. Our team of writers, editors, researchers, and product experts collaborates to thoroughly vet top products. We try to perform in-house testing on real vehicles whenever possible before making our recommendations.

When testing is not feasible, however, our aim is to make your life easier by doing all the online research for you and presenting that research in the form of easy-to-read product comparisons and buyers guides, rather than outright recommendations. For more information on our testing methodology and how we evaluate every product, check out our methodology page here.

What makes the NGK 7090 G-Power Platinum spark plugs stand out is the quality of their materials and their unbeatable price tag. The 7090's platinum-tipped center electrodes produce better conduction for starts, while its copper cores aid in heat removal for better thermal conductivity. And we can't overlook the pure alumina silicate ceramic insulator, which provides unmatched strength and heat resistance that give NGK spark plugs a reliable reputation. And at $20, it is hard for a lot of the competition to keep up.

Amazon Review Score: 4.7 out of 5 based on over 3,800 reviews

Many reviewers claim that the NGK 7090 plugs are inexpensive and easy to install. The few negative reviews cite shipping misorders but no issues with the plugs themselves.

If you’re searching for optimum performance for your vehicle, look no further than the NGK Iridium IX spark plugs. Although they are more expensive than other spark plugs, their longevity and ease of use are tough to beat, especially in hot engines.

One of the key features of the plug is its high melting point, making the plug more suitable for engines that are generally in a greater heat range than most vehicles. Other notable features include a fine iridium tip and trivalent metal plating, both of which contribute to better fuel economy, superior corrosion resistance, and a consistently stable spark for better starts.

Amazon Review Score: 4.7 out of 5 based on over 2,100 reviews

One complaint is that some customers needed to have the gap adjusted slightly on their plugs to make them fit their vehicles, yet many of these reviews were still ranked at 4.5 stars or above.

The Denso #5304 Iridium Power spark plug is great for improving the firing performance of your engine. It is one of the best iridium spark plugs on the market. The only real con is the price, which is higher than most of its competitors, but these plugs are built to last.

This plug's tapered-cut U-groove ground electrode increases ignitability and decreases quenching. Its five-rib insulator also helps prevent flashover, and the copper-glass seal bonds the electrode and insulator to provide a gas-tight seal. The quality of all of these materials is also high, so don't worry about these spark plugs breaking down quickly.

Amazon Review Score: 4.7 out of 5 based on over 500 reviews

Many reviewers note increased engine performance and better gas mileage after installing the Denso iridium plugs. Some of the top reviews also highlight the product's longevity with some reporting these plugs last over five years. Negative reviews complain that the Denso spark plugs do not fit their engine. These can serve as a gentle reminder that new spark plugs should be the same, if not similar, model as what your vehicle was originally equipped with.

HiVehicle New Iridium spark plugs are great for drivers who want high durability and a consistently stable spark. The 99-percent copper-clad electrode makes the plug great for conductivity, reducing the risk of false starts and breaking while working. HiVehicle also claims that its plugs improve fuel efficiency and emissions, as well.

One drawback to these spark plugs is that they are only compatible with select car brands: Chevrolet, GMC, Cadillac, Buick, Hummer, Oldsmobile, and Pontiac, making these spark plugs a limited option for other car owners.

Amazon Review Score: 4.5 out of 5 based on around 500 reviews

Many positive reviews come from owners of the car brands advertised and they confirm these spark plugs’ compatibility. They also commend the unbelievable performance of these plugs, especially their smoothness and stability. Negative reviews are scarce, with one review citing poorer engine performance after replacing the spark plugs.

AC Delco has been producing parts for General Motors for over a hundred years, and this dedication to quality is demonstrated by its ACD-OEM 41-962 spark plugs. Included in this listing is a set of Herlux spark plug wires, which help conduct power from the spark plugs. Although this brings the price of the package up, including these wires helps reduce the cost of buying them separately.

Notable specifications include a one-piece suppressor that creates a gas-tight seal great for reducing radio frequency and engine interference, as well as a pure copper core built for maximum fouling resistance.

Amazon Review Score: 4.7 out of 5 based on over 1,500 reviews

Many reviews commend the ease of installation of these plugs, with good remarks about the reliability of the spark plug wires, as well. There are a few negative reviews of this product, including some that say the plugs didn't match their engine.

Spark plugs provide a small electrical spark that ignites fuel inside the combustion chamber. This then pushes the cylinder down and moves the car forward – making spark plugs a necessary part of your vehicle. The biggest issue our team of experts found that customers had was purchasing improper spark plugs that won't work for their vehicles.

We cannot stress how important it is to take five minutes to read your owner's manual to ensure you purchase a suitable replacement. Double-checking which type of spark plug you need for your vehicle will ultimately save you time and money, whether you choose the NGK 7090 or the ACDelco 41-962.

There are a variety of signs that your vehicle needs new spark plugs, including but not limited to: engine misfires, increased fuel consumption, loud idle engine, poor acceleration, low horsepower, or a check engine light. Some automotive manufacturers suggest leaving the engine running for a few minutes to listen for abnormal sounds.

Yes. You can clean old spark plugs and reuse them in your car. Unfortunately, cleaned original equipment runs for a very short period of time before needing replacement and can even cause damage to your engine's combustion chamber, so it is wise to invest in quality spark plugs for the best performance.

Different types of spark plugs made from higher-grade materials can improve overall performance and cleaner starts. That said, all spark plugs essentially perform the same function, and most last thousands of miles.

Iridium spark plugs are made from stronger metals than copper or platinum models, so they wear much more slowly.

*Data accurate at time of publication.