Iridium spark plugs

During the operation of a gasoline engine, which is designed to include spark plugs, the owner is constantly faced with the need to periodically replace the spark plugs.

The correct choice of these elements will determine the stability of the internal combustion engine, the quality of combustion of the fuel-air mixture in the cylinders, temperature conditions, power, efficiency, exhaust gas toxicity, etc.

We also recommend reading the article on how to select spark plugs based on the make and model of your car. From this article you will learn about the features of selecting spark plugs for an engine.

It is worth noting that today, for most motors, manufacturers offer several product options, ranging from simple budget versions to new high-tech solutions. The latter include platinum or iridium spark plugs.

In this article we will talk about the difference between iridium and platinum spark plugs, and also try to answer the common question of which spark plugs are better, iridium or platinum.

Denso IW20, Denso W20 EPR

It’s not easy to pay about 3,000 rubles for a set of candles, knowing that your neighbor paid less than a hundred for similar ones. All the advantages of an expensive purchase are only in the future: the long mileage promised by advertising, some percentage of daily fuel savings, ease of starting... In addition, there is no need for frequent replacement: on a modern engine this is a labor-intensive and expensive procedure.

We decided to evaluate two polar designs from one reputable company in order to compare not the technology of different manufacturers, but the idea itself embodied in metal, all other things being equal. The choice fell on Denso.

Iridium IW20 are the obvious leaders in miniaturization of the central electrode: only 0.4 mm. It is the thin electrode that promotes better self-cleaning and, accordingly, extends the service life. They were accompanied by the usual W20 EPR-U. The initial difference in cost is approximately fivefold.

The difference between iridium spark plugs and platinum and standard spark plugs

Let's start with the fact that the main working element of any candle is the electrode. Spark plugs can be simple single-electrode (with one negative electrode) or multi-electrode. The typical product is a standard version with one center electrode and one side electrode. The spark in such an element constantly jumps between these electrodes, which leads to their relatively rapid burnout.

Multi-electrode spark plugs have one central electrode, while there can be from two to four side electrodes, depending on the design. This solution improves operational reliability, increases spark generation efficiency and power, and extends overall service life.

It is important to know that manufacturers did not limit themselves to just increasing the number of electrodes. In parallel with this, different materials are used for their manufacture. It turns out that most of the main characteristics of these elements will depend solely on the manufacturing features of the electrode part. In other words, we are talking about the material used to make the electrode or its tip.

For this reason, spark plugs are usually divided into:

copper or chrome-nickel;
platinum;
iridium;

This means that during the production of the electrodes, either a cheaper material was used (for example, chromium and nickel), or an expensive alloy of rare earth metals (platinum, iridium) was used. The final cost of the product directly depends on this.

An increase in CH toxicity indicates disturbances in the combustion process.

An increase in CH toxicity indicates disturbances in the combustion process.
An increase in CH toxicity indicates disturbances in the combustion process.

According to the resource, the count in engine hours is 360:240. In all operational parameters - from consumption to toxicity levels - iridium is also confidently ahead.

Hence the conclusion: if you have an expensive modern car and you put a lot of miles on it, it makes sense to spend money on iridium. But if the car is so-so, and only travels no more than 5 thousand a year, you are unlikely to recoup the investment. Such is the deceit of expensive things...

Mikhail Kolodochkin, and associate professor of the department of internal combustion engines of the St. Petersburg Polytechnic University, Ph.D. Alexander Shabanov

Choosing spark plugs: iridium or regular?

Choosing spark plugs: platinum or iridium

First of all, for normal operation of the internal combustion engine, it is necessary to select spark plugs that will be completely suitable for this type of engine. We are talking about the heat index, the physical dimensions of the candles, etc.

The heat rating is the most important parameter, as it actually shows the amount of heat that the spark plug takes on from the combustion chamber of the power unit. If a part overheats, then it can quickly deteriorate, leading to engine detonation, glow ignition, etc.

Too “cold” elements also work poorly in the engine, quickly become covered with soot, and the quality of spark formation and fuel combustion deteriorates. In this case, the so-called self-cleaning of the candles does not occur.

So, having decided on the basic parameters, you can then pay attention to three types of available solutions:

Standard;
Platinum;
Iridium;

Let us add that for a specific engine, internal combustion engine manufacturers often recommend using only iridium or platinum spark plugs, excluding standard ones. In parallel, each manufacturer (NGK, Denso, Bosch, etc.) additionally offers unique patented solutions in terms of the design of their products.

We also recommend reading the article about which spark plugs are better, NGK or Denso. From this article you will learn about the main advantages and disadvantages of these products from these brands.

For example, a u-shaped cutout may be made at the base of the side electrode; products may differ in the size of the gap between the electrodes for complete combustion of the fuel charge, etc. The standard will be simple copper or chromium-nickel spark plugs, which are affordable, but also have a short resource (up to 30 thousand km).

As practice shows, in the CIS with low quality fuel and on cars with LPG, standard elements may need to be changed every 20 thousand km. For this reason, many drivers opt for more durable analogues. Now let's figure out which spark plugs are better, iridium or platinum.

Features of iridium and platinum spark plugs

Platinum and iridium spark plugs are the product of more modern technologies, since the use of these metals in the electrode manufacturing process significantly increases the service life of the element. For example, a platinum spark plug, which is correctly selected for the engine, can reach 40-50 thousand km even on poor fuel. mileage In the case of iridium, this figure can be about 60-70 thousand.

Platinum and iridium spark plugs are resistant to carbon deposits, resulting in a stable and powerful spark. This allows the engine to burn fuel more efficiently, develop more power, etc.

Platinum spark plugs

The base material for electrodes is platinum or alloys using this metal. Platinum exhibits resistance to corrosion and withstands high temperatures well. This means that the central and side electrodes burn out much more slowly.

According to manufacturers, such elements retain their performance for up to 100 thousand km. mileage The spark from platinum plugs is more powerful and more stable compared to the ignition spark from regular plugs.
The use of platinum allows for a thin central electrode with low voltage, resulting in stable flammability.
The performance indicators of these elements are constantly maintained at a high level, since the gap does not undergo significant changes throughout the entire declared service life. This allows you to achieve good engine performance and at the same time save fuel.
For modern highly accelerated naturally aspirated and turbocharged engines, platinum spark plugs with a U-shaped profile can be found on sale. These products have a positive platinum electrode with a diameter of 0.7 mm. This profile allows for complete combustion of the mixture and makes it easy to start the engine.

The thinness of the central platinum electrode and the stability of the side ones, combined with a special profile, allow such parts to generate a stable and powerful spark, even when the voltage is reduced. Ultimately, the fuel in the cylinders burns with maximum efficiency.

Now let's move on to iridium spark plugs. These ignition elements are considered a new generation development. The use of iridium has improved the basic characteristics even compared to platinum analogues. The resource declared by the manufacturer is at around 100 thousand km, stable spark generation and better operation of the internal combustion engine are guaranteed.

The central electrode made of iridium alloy allows a diameter of 0.4 mm to be achieved. This means that the products will work even longer, more stable and more efficiently. Such elements allow the engine to most fully burn fuel in the cylinders throughout the entire declared service life.
The smaller diameter of the electrode of iridium spark plugs results in increased stability of spark formation under any conditions. The fact is that a thin electrode allows you to create a high electric field intensity. This suggests that less voltage is needed to create a spark.
We also note that iridium has a noticeably higher melting point compared to platinum and is more durable. It turns out that iridium spark plugs can withstand significant loads and are especially resistant to wear.

Also, candle manufacturing companies add additional components to the iridium alloy, maximizing the characteristics. Such additives make it possible to achieve resistance to oxidative processes from a thin iridium electrode. Iridium with rhodium is rightly considered one of the most effective alloys.

Does it make sense to use “long-lasting” candles if you can buy ordinary ones?

Choosing spark plugs: iridium or regular?

Replacing platinum

In 1994, NGK introduced iridium spark plug sets to the world, positioning them as a replacement for platinum spark plugs. They managed to achieve success, but why? Because this metal is more resistant to temperature, has higher strength, long service life and protection against corrosion. NGK created a thin wire, the tip of which consisted of iridium, which made it possible to fully use all the advantages of this metal in candles. In 1997, Denso launched mass production of improved models and now occupy the first position in the ranking.

conclusions

A review of iridium spark plugs from three global companies allows us to draw the final conclusion that iridium spark plugs are not only useful, but sometimes simply a necessary element of a car engine. In some modern cars, access to the spark plugs is closed, and replacing spark plugs turns into a labor-intensive operation requiring the use of specialized keys. Installing iridium spark plugs in these types of cars is simply necessary, as it will provide significant savings during further service and increase the service life of the engine.

Properties of iridium as a material

Innovative air-fuel mixture igniters are manufactured by laser welding of iridium electrodes. Melting point is about 2,500 degrees. Since the beginning of the 21st century, iridium has been used in industry for the production of igniters.

In the industrial industry, not pure iridium is used, but alloys. It is impossible to work with the material in its pure form - it is too fragile, its electrical conductivity is low. But alloys improve the quality of the final product many times over. Alloys are used to make electrodes with much thinner tips. With such components, the engine runs smoother and the car accelerates faster.

Observations

The well-known auto magazine “Behind the Wheel” compared two different types of spark plugs from the same manufacturer, Denso. Fuel consumption was measured over 360 engine hours.

To maintain engine performance, simple spark plugs required 4% more fuel after 180 hours of experimentation. Upon completion, this figure increased to 8.5%.

When the engine was running on iridium spark plugs, an increase in the amount of fuel consumed occurred only after 300 hours of operation. At the end of the experiment, fuel consumption increased by only 3%.

Background

Spark plugs were first modified at the end of the 20th century. Then the racers noticed that reducing the diameter of the central electrode made it possible to achieve an increase in the power of the power unit. We did this ourselves, using a small file - a needle file.

However, such innovations sharply reduced the service life of parts. Manufacturers took this point into account and began searching for an alloy that could increase the service life of spark plugs several times. And such an alloy turned out to be iridium.

The difference between a fake Denso and a branded product

It is possible that many manufacturers of counterfeit products have learned to counterfeit products very well, however, you can still try to distinguish the original iridium spark plugs of the Japanese company from the counterfeit ones. There are many different points that you should pay attention to when purchasing, and there are signs that help determine the authenticity of the product. Let's start with the most important thing, that is, with the electrodes; for example, let's take the Denso VK20 brand. For the original, the thickness of the central electrode should be strictly 0.4 mm, and on the side one the added contact made of precious metal is clearly visible (photo of the original below).

In a non-original, the “center” is usually noticeably thicker, and the additional contact turns out to be smeared, which is what a fake looks like, you can also see in the photo below.

What other signs of the original product can be noted:

the inscription on the insulator is made neatly and clearly, without blurring the font;
the sealing ring cannot be twisted; it sits tightly on the thread;
the internal insulator of the central electrode is placed strictly in the center, without deviation in any direction;
the outer insulator has a smooth surface, without roughness;
The thread on the original is knurled and is made almost perfectly.

Of course, having bought a fake in a store, it is difficult to then convince the seller that it is a counterfeit, but in this case you can contact the official Denso representative office.

Does it make sense to use “long-lasting” candles if you can buy ordinary ones?

Subtleties of choosing suitable spark plugs for cars

If you want to choose candles, you first need to pay attention to the heat number. This is an indicator that determines the operating temperature of the components located in the engine cylinder.

Why is the heat number the most important criterion:

If you choose the right heat value, during operation the candle will be able to heat up to the desired temperature and self-clean.
When the temperature is below the required level, carbon deposits will cause incorrect sparking - misfires will appear, fuel consumption will increase, and power will decrease.
If the indicator is much higher than normal, glow ignition occurs - dangerous and uncontrollable.

Paying attention to the heat rating, hot, medium, optimal, cold and unified versions are distinguished.
Other indicators are also important during selection:

Standard size - depends on the parameters of the motor, here the diameter, length and pitch of the thread are studied;
The size of the hex head, which is reduced, medium, normal and enlarged;
Sealing - performed by means of a conical joint or a washer made of soft metals (prevents the penetration of crankcase gases);
Electrodes - there are differences in quantity and presence, therefore, there are simple single-electrode, more complex multi-electrode, torch, plasma-prechamber versions (the latter option ensures maximum speed and completeness of combustion of the fuel mixture).

When thinking about how to choose spark plugs for a car, it is worth studying the operating instructions, which indicate the optimal parameters and brands recommended by the manufacturer. In the absence of technical documentation, the existing candles are carefully removed and the required product is determined by the applied markings.

There are also special services that carry out selection by car make and model.

Best manufacturers:

Bosch – Offers an impressive selection of products, including platinum, multi-electrode models.
NGK is a well-known Japanese manufacturer whose products are often used in the assembly of cars in factories.
Denso - this brand produces 4 series, which include not only platinum, iridium, but also special offers - spark plugs with nickel electrodes, the service life of which does not differ.
Brisk is a Czech brand that offers classification depending on the type of power unit.

Important:

When installing iridium or platinum spark plugs, do not forget that their service life depends on the fuel. If the quality of the fuel does not meet the stated standards, the indicator is reduced by 20–40%. And the usual mechanical and other cleaning methods are strictly prohibited here.

In the CIS countries, the quality of fuel does not meet standards, which is why the service life of platinum and iridium models will be practically the same, although the price of the latter is much higher. But each motor has certain requirements.

And if the automaker indicates the need to use iridium models, then they are installed; in other cases, platinum ones are used.

Candle sizes

Candles are divided by size. Not only the length of the entire candle differs, but also its individual parts. The devices differ in the length and type of thread, the diameter of the spark plug, and the size of the screw head. It is not necessary to know all the subtleties; you just need to focus on the length of the thread. There are three classes here:

short (12 mm);
long (19 mm);
extended (25 mm).

Try to take into account the sizes. Otherwise, you risk damaging not only the new part, but also the structural elements of your car’s engine.