A Comprehensive Comparison: OEM Spark Plugs vs NGK

Are you getting compromised performance from the vehicle engine? May be the spark plugs are not functioning well. If you get them defective, it’s time to replace them with new ones. Thus, the topic OEM spark plugs vs NGK arises, and many people get confused selecting between these two items.

In short, Original Equipment Manufacturer or OEM spark plugs are the default part of any internal combustion engine. OEM spark plugs come from the same manufacturer of the machine. For example, XYZ OEM spark plugs are made by XYZ brand. Alternatively, a Japanese company, NGK Spark Plug Co., Ltd. produces the NGK spark plugs.

So, which one will be better for particularly your vehicle engine? Is it OEM or NGK? Thus, I am here to discuss the comprehensive comparison between these two types of spark plugs. Once you read the full content, you can decide between them to keep the engine performing well.

Side-by-Side Comparison – OEM Spark Plugs vs NGK

Let’s have a glance at the table!

A Comparison Table of OEM Spark Plugs versus NGK Spark Plugs

OEM Spark PlugsNGK Spark Plugs
Default or pre-installed equipmentReplacement equipment for OEM
Different brands have different OEM productsOnly NGK produce NGK spark plugs
Comes with specific brand of vehicle or engineComes as both OEM and aftermarket products
Provides the same optimal performancePerformance varies depending on several factors
Most OEM items are fuel efficientFuel quantity depends on models and types
Costs are almost fixedMay vary more than OEMs
Lasts for more milesLasts for moderate or close to OEM’s duration
More reliable than other OEM or aftermarket spark plugsMore popular and available than specific brand’s OEM parts
Updates comparatively slowlyUpdates sooner than OEM plugs
A bit shorter and less spark than NGK plugsMore vivid and longer than OEM items

Performance Variation

NGK is more updated and trendier than any particular OEM spark plug manufacturer. They use high-quality materials and advanced technology. As a result, you get improved ignition and fuel efficiency.


It’s tough to decide between the two spark plugs as both OEM and NGK spark plugs for a long duration. You may not need to replace them very soon. But many people consider NGK plugs for a longer lifespan than OEM spark plugs due to the advanced materials and design.


In this case, NGK is the winner. This brand produces more affordable spark plugs than specific OEM plugs. Mostly, the reason behind it is the brand name, and they are manufactured by the vehicle or engine’s original manufacturer.


If I talk about availability, OEM spark plugs stay ahead of NGKs. You can find OEMs in more stores as they are produced by the same company that made the vehicle or engine. NGK spark plugs are becoming popular every day, increasing availability at most auto parts stores or online retailers.

Spark Quality

“In my opinion, I see the NGK spark as longer and brighter. Also during the slow motion video the NGK spark seemed very straight and consistently hit the same point of the tip.” – according to a user on VN750.

OEM Spark Plugs

OEM items are named after the engine where they are installed and come direct from the same manufacturer. For instance, if you have a Harley Davidson, you get Harley’s OEM spark plugs installed in the combustion chamber.

An interesting fact is that OEM spark plugs are typically the same type installed in the factory vehicle. Let me explain it more precisely. Suppose you want OEM plugs for a particular Harley motorcycle. But somehow you cannot get it in your area.

Still, you can use OEM spark plugs from other manufacturers. In this case, you get the imitated type of default OEM spark plugs. These types of equipment are specifically engineered to work with the same engine’s design and fuel system.

Benefits of OEM Spark Plugs

These engine parts are dedicated to working on a particular vehicle’s make and model. Thus, using OEM spark plugs in your vehicle engine has multiple benefits. Some of them are:


These items can fit and work optimally with the engine and ignition system of a particular vehicle make and model. Installing them gives you enhanced engine performance, fuel efficiency, and reliability.

You can buy OEM products from different manufacturers if there is difficulties in getting products from the mother manufacturer.

Build Quality

If you compare OEM with aftermarket products, you will indeed find prior ones better. According to Toyota, “A quality OEM plug has a nickel-plated steel shell, as nickel is both corrosion resistant and unlikely to cause a plug to seize in the threads on the cylinder head.” This nickel coating is comparatively thicker than other ordinary spark plugs.

In the same post, Toyota explains that OEM spark plugs have high-quality ceramic insulators. They can prevent fractures during installation or the temperature rise. Hence, ordinary spark plugs have low-quality insulators. Also, this company uses premium platinum or iridium tip in their OEM plugs. They are good to last longer than their aftermarket counterparts.


If your OEM plugs get damaged or malfunction now and then, you can claim your warranty. Any manufacturer producing OEM gears offers specific years of warranty. Till the warranty limit, you can get a free replacement. But if it exceeds, you must look for a new one after spending money. Aftermarket spark plugs may have less or no warranty duration.


According to DIYCarServiceParts, an OEM spark plug can last up to 80000-10000 miles of car driving. Cars.com says the lifespan of a car OEM spark plug can be 100000 or more miles. You can stay worry-free if you install these plugs in your car.

In the case of motorbikes, the lifespan is almost 15000-20000 miles. (Source: MotorcyclePowerSportsNews)

All these numbers may change depending on how you use the vehicle. Excessive turning on/off the engine can reduce the build quality and performance of the OEM spark plugs. However, you can stay worry-free installing them for more duration than aftermarket products.

Disadvantages of OEM Spark Plugs

Some disadvantages are also there if you prefer OEM spark plugs:


As they are precisely made of specific models of vehicle engines, they are more expensive than ordinary ones. It is mainly for their high quality and precise manufacturing processes.


You cannot install an OEM item on other vehicles or engine models.

NGK Spark Plugs

You can find these items from the stores that sell NGK products. A Japanese company named NGK Spark Plug Co. Ltd. produces these spark plugs. Likewise, this company is an expert in making versatile ignition components for internal combustion engines.

The journey of NGK spark plugs started in South Africa in 1950. At that time, people knew the company as Lectrolite. But the products were licensed to NGK Spark Plugs Japan which NGK Japan now owns. Now, you can buy different OEM, P&A, and aftermarket spark plugs.

According to Vehicle Maintenance and Repairs, NGK plugs are suitable for their superior build quality, stable performance, and versatile compatibility. These features can remain close or the same as OEM spark plugs.

Benefits of NGK Spark Plugs

You can find different spark plugs from NGK, including OEM ones. In general, you can get these benefits if you choose their products:


Like OEM, NGK spark plugs are made from high-quality materials. Typically, these items have various cores like standard, copper, platinum, iridium etc. These cores help to withstand and operate at high temperatures and pressures. So they can last for miles or years.

NGK plugs have laser-welded iridium center electrode tips. It helps to work at the same pace as OEM plugs. Also, you can stay worry-free for a long duration if you install them in your vehicle.

Improved Engine Performance

You may think of engine performance when replacing OEM with NGK spark plugs. But these plugs are also winners for providing reliable ignition. As a result, you can experience improved engine performance, better fuel efficiency, and reduced emissions.


These plugs are available in various configurations. You can install them in vehicles like cars, motorcycles, boats, and small engines. Even you can find almost the same OEM spark plugs installed already in your vehicle engine.

Enhanced Ignition

NGK spark plugs feature advanced design and materials. So, they allow faster and more efficient ignition, reducing engine misfires. You will get overall improved engine performance.


You can find them in most stores because it is not only an OEM spark plug manufacturer. But it can be issued to some areas where you may see them. You will feel the maintenance and repairs are challenging in those areas.


NGK products are often costlier than other brands of spark plugs. For a tight budget, you may avoid NGK and buy other brands available in the market. Still, these plugs are more affordable than branded OEM products.

Disadvantages of NGK Spark Plugs

Like OEM, you can also find critical issues regarding NGK spark plugs:

Core Selection

The inner core of the spark plug is essential. Also, NGK offers different plugs made with a wide range of materials. But variations like standard, copper, and iridium can confuse you soon.


These spark plugs are practically designed to work with the specific model. But if you install it on a non-compatible vehicle, you may experience poor engine performance or damage.

Final Words

So, which one is a winner in the debate on OEM spark plugs vs NGK? I will choose any of them as both spark plugs are the most popular options on the market.

OEMs are ahead for compatibility with your vehicle’s specific make and model. They offer consistent performance and reliability. Alternatively, NGK spark plugs offer advanced materials and technology. These things can provide improved ignition, fuel efficiency, and durability.

You can save more money on NGK equipment. But if you want a spark plug for a specific vehicle model, then OEM is better for its availability in brand shops.

Overall, it’s up to you, depending on your motives. I have explained all the features in detail to help you select the right one. Just consider the facts to make the selection better and more successful.

Thanks for reading the blog and sharing your moments.

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