Denso vs NGK: Which Spark Plug Is Better?


Spark plugs are used to ignite the air and fuel mixture inside the car and burst the engine to life. These are small but essential parts of a car to make it run. Two of the most popular spark plug brands are Denso and NGK. So Denso vs NGK spark plugs, which one is better?

It’s not easy to choose between NGK and Denso spark plugs since both are iridium, making their performance almost similar. However, Denso spark plugs’ electrode shrinks faster than NGK’s, shortening its lifespan. Note, however, that Denso plugs are more powerful than NGK units.

Read on to know more about Denso and NGK spark plugs so you can purchase the one that is right for your car.

Denso vs NGK

denso vs ngk

To give you more insight as to which of these two products is better, let’s compare Denso spark plugs with NGK spark plugs based on the following parameters:

  1. Performance
  2. Lifespan
  3. Special Features
  4. Cost
  5. Availability
  6. Maintenance

1. Performance

Both Are Highly Functional Spark Plugs

Regarding performance, the battle between Denso vs. NGK is head-to-head. Both are highly functional spark plugs that can work on almost any type of vehicle. They work great because they are made of iridium, which is less conductive than copper and is known to last longer. As such, iridium spark plugs work at lower temperatures.

Another popular material for spark plugs is platinum. Between platinum and iridium, the latter costs up to five times more. Iridium spark plugs are tougher and more stable. Also, the gap between iridium metals won’t grow over time or produce more stress on the car’s ignition system. This makes iridium a better choice than platinum spark plugs.

Both Are Iridium Spark Plugs

Since Denso and NGK are both iridium spark plugs, it is quite hard to judge the winner between them based on the material used alone. However, compared to the quality of spark the two produces side-by-side, Denso spark plugs are more powerful. So, if you want a spark plug that can produce a slightly higher horsepower for your vehicle, Denso is your choice.

Engine Equipped with a Denso Spark Plug Performs Better

Improved combustion has long been the salient point of a Denso spark plug. This means that the cars’ engine equipped with a Denso spark plug performs better and consumes less fuel. The Denso Iridium TT spark plug creates the highest spark explosion compared to other spark plugs of the iridium type.

2. Trust Score

When it comes to the two brand’s trust scores, both companies are not too far behind each other. NGK was established in 1936 in Nagoya. On the other hand, Denso was established in 1949 in Japan. So, if you’re going to gauge the performance of their products based on the company’s reputation, then NGK was almost a decade ahead of Denso in the spark plug market. If that means something to you, the former would be your choice.

However, Denso is partially owned by renowned car manufacturer Toyota. This means it is a trusted brand when it comes to Japanese cars. Since Toyota backs up this spark plug, you can expect that Denso offers the same level of quality and durability with its products as the Toyota car brand.

3. Lifespan

denso vs ngk spark plug wires

Lifespan is another major consideration when it comes to spark plugs. Some cars have their spark plugs installed under the engine, making it difficult to remove and replace. This makes lifespan or longevity a crucial factor when choosing a spark plug for certain vehicle owners.

NGK Spark Plug Lasts Longer Than Denso

The NGK spark plug proves to be superior to a Denso when it comes to lifespan. This is because it has been observed that the electrode used in a Denso spark plug tends to shrink more after a certain period.

If you are concerned about buying a more consistent and longer-performance spark plug for your car, then the more obvious choice is NGK. The average lifespan of these spark plugs is between 40,000 to 60,000 miles. However, Denso counterclaims that, despite the circumstances, theirs can last up to 100k miles.

NGK Spark Plug’s Tip Is Made with Irridium Alloy

While NGK spark plugs are designed to last longer and provide superior ignitability, it also has other good features, such as sharper throttle and anti-fouling characteristics. This is made possible by the spark plug’s tip made with iridium alloy. NGK spark plugs provide consistent performance in cold and hot weather.

Denso Made Sure Every Unit Was Precision-welded

However, Denso’s spark plug won’t be left behind when it comes to longevity. To make their spark plugs last longer, they ensured that every piece was precision-welded. Denso uses 360-degree laser welding to provide longevity and lasting performance on their spark plugs.

Again, Denso vs. NGK – which is better? Denso spark plugs produce more powerful sparks. However, its electrodes shrink faster than NGKs. However, note that both are iridium, making the two brands’ performance almost the same.

Symptoms of Bad Spark Plugs – and When to Replace

4. Special Features

NGK’s Long Insulator Nose

Both Denso and NGK have special features inherent to their spark plugs. For NGK, that would be its long insulator nose. This feature prevents the spark plug from fouling, even if used for about 100k miles. Another good feature of the NGK spark plug is the insulator’s corrugated ribs. This feature eliminates spark flashover so that proper combustion is achieved whether your car is sitting idle in traffic or running full speed on the highway.

Denso’s Twin Tip Technology (TT)

Denso has added one unique technology to their spark plugs: the Twin Tip Technology (TT). The Iridium TT spark plug has two tips:

  • Tip #1: Platinum ground electrode measuring 0.7 millimeters.
  • Tip #2: Iridium center electrode measuring 0.4 millimeters.

This technology allows for minimal obstruction between the electrode and the ground, thereby providing a more powerful explosion inside the combustion chamber.

5. Cost

NGK Is More Affordable Than Denso

Like with any other product, the cost is among the top considerations of many buyers. Simply put, Denso is generally costlier than NGK. If you compare the two iridium spark plugs of almost the same features as these two manufacturers, you’ll see that NGK is priced slightly lower.

So, if the price is of sheer importance to you, you might want to consider buying an NGK. Its performance doesn’t lag too much behind Denso’s, and it technically lasts longer too. But do note that there are other spark plugs in the market. The ones made of copper or platinum are cheaper than those made of iridium.

Both Brands Have Different Varieties Available

Do note that Denso and NGK have different varieties available. Be sure that you do so at the right standards when comparing prices. Carefully check the features of each spark plug before you check their price tag.

But more than just the spark plug price, users should also check the maintenance costs of these products; this is where the product with a longer lifespan and better performance comes into play. If maintenance costs override the product’s price, then you’re not saving up anything.

6. Availability

Denso spark plug is widely used in Japanese cars. Therefore, if your car is a Japanese brand, you’re more likely to find an exact Denso spark plug replacement. On the other hand, NGK is a worldwide brand. As a trusted name in the auto industry, you’ll likely find an NGK spark plug that would work on your car, regardless of its make.

So, when it comes to availability, it will all boil down to the type of car you own. Both manufacturers originated from Japan and ship globally, so you will likely find a store carrying their products near you. Denso has spark plugs easily available for Toyota, Scion, Subaru, and Lexus cars. For all other brands, there’s an NGK that will suit your vehicle.

7. Maintenance

denso vs ngk spark plugs

When it comes to car parts, you should give importance to maintenance. Generally, NGK and Denso spark plugs require maintenance every six months, particularly the iridium types.

NGK Spark Plugs Require Less Maintenance

But if you compare these two brands side by side, NGK may be ahead of Denso when it comes to maintenance. NGK’s spark plugs are more stable, allowing them to work longer and require less maintenance.

Installing an NGK spark plug is also easy. You bolt it inside the car’s motor, and that’s about it. If you’re a good driver, you may even use the spark plug up to 80,000 miles without any issue. But of course, that’s going to depend on a lot of factors.

Denso Is Ahead of NGK in Terms of Mileage

On the other hand, Denso claims their spark plugs can go up to 100k miles without issues. In the perfect world where both products were used in optimum conditions, it’s clear that Denso is ahead of NGK when it comes to mileage.

Conclusion – Denso vs NGK: Which Spark Plug Is Better?

Considering all the abovementioned factors, you can decide the Denso vs. NGK battle winner. As you can see, both brands have something unique and valuable to offer. But then again, it will all boil down to finding out which one will suit your vehicle best rather than trying to find out which brand is the better one.

Here’s a quick run-through of the points listed above:

  • Performance – Denso if you want higher combustion
  • Lifespan – Both have made their products last longer with proper use and maintenance
  • Special Features – Both have good features and uses certain technologies to make their products better
  • Cost – NGK if you want the cheaper iridium spark plug in the market
  • Availability – Denso if you have a Japanese-brand car, mostly a Toyota; NGK for all other brands
  • Maintenance – Denso claims to require minimal maintenance up to 100k miles; NGK has a lower maintenance cost in the long run

To recap the salient points discussed above, Denso generally creates a much more powerful spark than NGK, but the diameter of the electrodes in their spark plugs tends to shrink more than that of the latter. As such, a Denso spark plug may not last longer than an NGK.

Many people may have different views regarding the two spark plug brand, but there are no right or wrong views here. It’s because there’s no definite answer. The better spark plug is the one that works well for your vehicle. If anything, you should first check your car’s manual before buying a spark plug, or any car part for that matter.

Just remember that a car engine is manufactured under different conditions and tolerances. Any deviation from the configuration from wrong or faulty parts will significantly change the engine’s performance in many ways. In the end, it won’t matter which form Denso vs. NGK emerges as the winner. What matters is you’re using the right kind for your vehicle.