Iridium or platinum spark plugs, service life and main differences

Automotive spark plugs (SPS) provide an uninterrupted spark to ignite the air-fuel mixture; engine power, fuel consumption, and ease of starting the engine in cold weather depend on the stability of their operation and characteristics. These parts have their own specific lifespan, and in order to replace them less frequently, car owners often install iridium spark plugs (ISPS) on their cars. But you can’t simply install spark plugs on a car without selecting them; they have different parameters such as heat rating, thread diameter and length, and edges for the spark plug wrench. Last but not least is the service life of “consumables”, so you should approach the choice of SZ carefully and do not buy any brand at random.

Iridium and platinum spark plugs.

The service life of platinum candles is significantly higher than that of conventional ones. But it lags a little behind iridium ones. The service life of iridium spark plugs is considered maximum.

That is, the most reliable and durable are iridium spark plugs.

Difference between iridium and platinum spark plugs: The platinum spark plug has a slightly narrower center electrode. And on the side there is a platinum soldering.

But it is not as thin as an iridium spark plug.

An iridium spark plug has a central electrode 0.4 mm thick. About the size of a hair. The side electrode has a U-shape. Previously, the difference between them in cost was about 40%. An iridium spark plug was forty percent more expensive than a platinum spark plug. Although a platinum candle is also not cheap. But with the development of technology, their prices have almost become equal. The main thing is not to fall for a fake!

If you want to buy yourself platinum spark plugs, then the declared resource will be about 80,000 km. When purchasing a spark plug, be sure to pay attention to the side electrode. No one will ever put this small, barely noticeable solder on a fake. As for iridium spark plugs, counterfeiting them is much more difficult. The reason is the thin central electrode. If it is made of another metal and is not coated with iridium, then there is a risk of it quickly burning out. And for every purchase, as you know, you are required to provide a guarantee. It is for this reason that they are rarely counterfeited. But in the Celestial Empire they can fake anything. So, be careful when choosing a candle!

Pay attention to the side electrode. It should be made in a U-shape.

And the declared service life of iridium spark plugs is more than 100,000 km. If it is difficult to change spark plugs on your car, you have a “fresh” engine and low mileage, then pay attention to iridium or platinum spark plugs. Once you install them, you won’t have to look there again!

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Iridium

Iridium is the hardest silvery-white metal on the planet. Its electrical resistance is second only to gold and silver, and its melting point (2454°) is second only to molybdenum (2620°) and tungsten (3420°). In addition, the precious metal iridium does not oxidize during combustion.

The properties of iridium lead developers to use the metal in the central electrode. Its resistance to deformation, strength and ability to withstand heavy loads are manifested in alloys; without them, working with metal is impossible due to the fragility of the material and low electrical conductivity.

Peculiarities

Iridium spark plugs are distinguished from other products by their thin tip width, achieved through laser welding of the electrodes and iridium as a conductor. The average thickness using iridium is 0.4 mm, while the thickness of alternative types and subtypes is from 1.5 mm to 2.5 mm.

A thin rod allows you to concentrate the charge of electricity on a small area, rather than dissipate it over the entire surface in the case of a larger electrode area and, as a result, increase the quality of the spark gap.

Thanks to this system, fuel burns as completely as possible, regardless of the selected speed mode, and the engine runs smoothly without interruptions.

Denso IW20, Denso WEPR

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.

SIP

In 2003, it presented super spark plugs, produced under the name SIP. Thanks to thin electrode technology, high quality and long service life, they are most in demand on the production lines of the largest middle-class car manufacturers. The range of these candles is unusually wide. Judge for yourself. There are more than 11 thousand models for motorcycles and small marine engines alone. What can we say about cars?

Their popularity is due to:

the possibility of improving the flammability of the fuel mixture with their help;
reduction in fuel consumption up to 5%;
increasing the power of the power unit up to 4%;
long resource (100 thousand km);
a huge range of modifications.

Advantages

Experiments to improve standard products were not in vain. The properties of iridium and the characteristics of iridium spark plugs have led to a number of advantages over outdated products made from other metals and alloys. Among which:

The use of a product using iridium on average increases the overall engine power by 7%. In some situations the percentage increases more and leads to tangible improvements;
The service life of iridium spark plugs significantly exceeds other types and subtypes. Replacement is required no more often than after 100,000-150,000 km (the service life of previous types and subtypes is 10,000-20,000 km). It is this property that compensates for the high cost of a product using iridium;
the required fuel costs are reduced by 7%, due to a more powerful spark providing volumetric ignition. In addition, toxic emissions that are harmful to the human body and the environment are also reduced;
It doesn't take much effort to start the engine. Even in adverse weather conditions (low temperatures), the engine starts quickly and without additional assistance. This property is especially important in areas with harsh climates, where the temperature in winter drops to 40°.

Thus, manufacturers not only corrected the problems of previous products, but also introduced a number of new advantages.

Flaws

Despite improvements, iridium spark plugs need to be refined and improved. The advantages and benefits of candles using iridium are complemented by several significant disadvantages, including:

There is a significant difference in price between iridium spark plugs and regular spark plugs. At the same time, the purchase of simple spark plugs cannot be called profitable or economical, since the service life of iridium spark plugs is many times longer. Choosing a product based on pricing is wrong and can lead to even greater waste;
unjustified use on conventional engines. Iridium spark plugs are aimed at modern models and for high mileage; if both the first and second are missing, all the positive aspects, with the exception of increased service life, disappear. Combining iridium spark plugs and an old car model will not bring impressive results.

If the first minus is justified by the quality and service life, then the second directly affects the decision to purchase iridium spark plugs. The costs will not be recouped without a powerful engine and frequent use of the car.

What about the high price?

The main problem when choosing iridium spark plugs is their cost, which forces car enthusiasts to give preference to more affordable products.

But here it is important to note that candles using iridium will be cheaper than platinum products, which are also considered one of the best.

There is an opinion that the inflated cost is due to the rarity of the metal, because iridium is less common than gold or platinum.

In fact, price formation occurs according to a different principle.

Manufacturers focus on the demand for specific products, the characteristics of the automotive spare parts market, the presence of competition, and so on.

Today, purchasing iridium spark plugs will cost less than platinum spark plugs. But this situation can change at any moment.

In practice, almost a fifth of the rare metal that is mined on the planet is spent on the production of iridium candles.

As for the more famous platinum, it is mostly used for making jewelry, with only a small percentage involved in the production of candles.

An important point is the amount of metal used in production.

As in the case of iridium and platinum spark plugs, the use of expensive materials is minimal.

Only two elements are made of iridium or platinum - the grounding electrode and the tip of the part.

As soon as the demand for candles using iridium increases, the consumption of this metal increases and the price increases.

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Why iridium?

Such a wide selection of candles pampers car enthusiasts only for 20-25 years. Before this, the choice was much poorer.

Platinum candles were already on sale, but one could only dream of decent quality or reliability.

The best manufacturers in the world did everything possible to improve the quality of the product and achieve their goals, namely ensuring maximum reliability, long service life and reducing energy consumption.

In 1994, NGK specialists finally managed to create high-quality spark plugs using a special material - iridium.

What are its advantages? — It has a maximum melting point (in this indicator, iridium surpasses even platinum), excellent anti-corrosion properties and high quality.

The developers managed to make the thickness of the electrode minimal. Moreover, it was the tip that was made of rare metal.

In terms of its hardness, iridium occupies one of the leading positions. Many believe that the metal is based on the material of a meteorite that arrived on our planet many millions of years ago. Hence its hardness indicators.

Another advantage of iridium is its ability to withstand high temperatures. Metal can only be melted when heated to 2,500 degrees Celsius.

Iridium has been actively used in the industrial sector (since the 20s of the last century). But in practice it is not used in its pure form, but in the form of a special alloy.

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This is not surprising, because without the addition of metals, iridium is extremely fragile and useless in production. That is why in practice only alloys are used.

WHY DO CANDLES AGE?

What happens to candles during their operation? Why do their numbers change?

There are several factors. The most important thing is erosion of the metal of the electrodes under the influence of repeated intense spark discharge. As erosion processes develop, the size and geometric shape of the spark gap change. As the gap increases, the intensity of the discharge decreases, up to its complete cessation in some operating modes, in which the conditions for spark formation and initial ignition of the mixture in the cylinder are difficult. This is idling, maximum load, cold start.

In addition, as work progresses in the cylinder, the surfaces of the insulator and electrodes are covered with a layer of carbon deposits - under certain conditions they are conductive. In extreme conditions, it can form so-called soot bridges that bypass the spark group of the spark plug.

Under the influence of high temperatures, the protective coating of the candle insulator (glaze) is likely to be destroyed - the ceramics begins to become saturated with sediment particles. The candle's resistance to breakdown decreases.

Finally, thermomechanical cyclic stresses in the insulator can also lead to its destruction.

What is iridium and its history

Currently, many car enthusiasts prefer iridium spark plug sets. This is due to the long service life of the products, the highest quality and long service life, which increases the power of the vehicle. Their only drawback is the high price, which not everyone can afford. The high cost is explained by the fact that iridium is a rather rare and hard metallic formation.

It is believed that the material appeared many years ago on our planet due to meteor showers. In addition to the above properties, there is one more merit that makes it indispensable in the automotive industry - its high melting point (2500°C) . However, as it turned out, in its pure form the material does not possess all of the above properties. Since it itself is more fragile and has lower electrical conductivity. Therefore, they began to use it only at the end of the 20th century, and then as part of various alloys, which just complemented the missing properties.

Replacing spark plugs

Selection options

We won't talk much about the choice. The choice is made in accordance with the technical parameters of a particular vehicle. When purchasing, it is important to buy the original and not a fake; we will tell you more about their differences below. Denso's official website offers a great opportunity to consumers. In accordance with the parameters entered into the form about the car, the system automatically calculates and provides the user with SZ models, the use of which is allowed in the car.

NGK or Denso?

There are currently many manufacturers of spark plugs: you can buy iridium spark plugs either from a large factory with a well-known name or from a small Chinese company.

Candles from two companies are in stable demand - Denso and NGK. Whose products should you choose?

Denso iridium spark plugs are the latest generation of products; their service life can reach 7 years. The developers managed to reduce the electrode to 0.4 mm, which guarantees a soft start of the engine in any weather. In addition, Denso spark plugs reduce the time it takes to accelerate a car, reduce engine noise when idling and reduce fuel consumption.

NGK spark plugs are of equally good quality: it is not without reason that many automakers use them for standard equipment in the cars they produce.

The choice of manufacturer is a matter of personal preference, since both companies supply high-quality products to the market without having obvious advantages over each other. The main thing is not to forget that the more famous the company, the higher the risk of running into a fake , so it is better to buy candles in specialized stores that have quality certificates for the goods they sell.

Selection of spark plugs by engine type (by car make)

Anyone, even a novice car enthusiast, knows perfectly well that SZ can have different threads both in diameter and length, therefore, when buying these “consumables” in stores, they take a sample with them for selection. Also, spark plugs can be made to fit different keys for screwing in, since spark plug wells in the cylinder head are different (sometimes very narrow), the most common sizes for a “spark plug” are 16 and 21 mm. But not all drivers are aware that spark plugs are selected according to their heat number (HN), there are “cold”, standard and “hot” ones, their characteristic differences are:

“hot” plugs (HSS) - with a large heating zone, with a low CN (for Denso it is below 20, for NGK - no higher than 5), with a low ability to remove heat from the insulator, mainly used on simple atmospheric internal combustion engines;
“cold” (HSZ) - with a high heat rating, with excellent heat removal, used on forced engines.

If the GSZ is installed on a forced engine, the electrodes of the spark plugs may melt, as a result of which the engine itself may be damaged. When installing KhSZ on a low-speed naturally aspirated engine, excessive carbon formation occurs and misfires occur. For the correct selection of spark plugs, special catalogs have been developed where you can select parts for a specific car make and type of internal combustion engine; there are also tables of their interchangeability from different manufacturers.

Main characteristics of iridium spark plugs

The secret of modern iridium spark plugs is that the electrodes are connected using laser welding. Due to the good conductivity of the material, it allows you to create very thin tips of a very small size, which is very advantageous in comparison with the use of copper and platinum. In addition, this does not in any way affect the service life of iridium spark plugs.
Set of iridium spark plugs
The small diameter of these spark plugs creates a more concentrated electrical charge, which in turn allows for a small voltage to be created to cross the spark gap. This will make the car run smoother, accelerate faster, and improve combustion during any type of driving. Iridium allows the electrodes to be at an equal distance at all times and hold the spark.
Number of side electrodes. The standard option is one central and side electrode. Models appeared consisting of two, three, and four electrodes. New – without side electrodes.
In addition, iridium has the highest strength and the ability to consistently maintain a spark. Iridium will retain all its advantages in any situation. Its density is 22.65 g/cubic. cm. Because of this, the material is heavier than osmium. The hardness of the element is 6.5 on the Mohs scale, does this mean that the material is not subject to wear.
Due to the high melting point of iridium alloy, it is suitable for use in most high-tech engines with high operating efficiency. The temperature of the working spark plug in all engine operating modes should be somewhere between 500–900 degrees Celsius.
Trivalent nickel coating perfectly protects parts from corrosion. Much less voltage is required to create a spark, since the entire potential difference is concentrated in the tiny tip of the spark plug. In addition, iridium can improve vehicle acceleration and increase fuel efficiency.
Iridium spark plugs DENSO

Basic properties

The first company to use iridium, thereby improving the quality of SZ, was the Japanese company NGK. The reason why iridium was chosen was that this metal has a very high melting point, exceeding even platinum. In addition, it has high resistance to corrosion processes.

The reliability of spark formation can be increased by increasing the gap between the electrodes or reducing the diameter of the central electrode due to the use of chemically resistant noble and refractory metals for its manufacture. If you increase the gap, it becomes necessary to increase the voltage for sparking. When using noble metals, the cost of protective equipment increases. Manufacturers have taken both paths.

Since the 1980s, iridium in the form of an alloy has been used to produce igniters. Due to its fragility and low electrical conductivity, iridium is not used in its pure form. Its best properties are manifested in alloys. Iridium electrodes are made by laser welding. The iridium alloy is a good conductor, so it became possible to reduce the diameter of the central electrode.

Due to the small diameter of the tip, high voltage is not required to form a spark; the charge is concentrated on a minimal area. Therefore, high-quality ignition is guaranteed in any driving mode, and the fuel will burn completely. The engine power increases, it runs smoothly without failures, which allows you to quickly gain speed. Iridium maintains a constant gap between the electrodes, ensuring the safety of the spark and eliminating problems with starting the power unit.

The following main properties can be distinguished:

the high melting point of iridium alloys makes it possible to use these products for high-tech engines;
iridium tips of minimal diameter have high strength, which guarantees a constant spark to ignite the fuel assembly and start the engine in any weather;
Nickel coating of devices increases anti-corrosion and anti-blocking properties;
the voltage is supplied to the thin tip, so large values are not needed for sparking;
Iridium SZ have good efficiency during fuel combustion;
Long service life due to the high melting point of iridium.

Maintenance and replacement of spark plugs

Although manufacturers of iridium spark plugs for cars claim that they need to be replaced every 150-160 thousand kilometers , experts recommend doing this somewhat more often. This is due to the fact that the duration and efficiency of their operation are strongly influenced by the frequency of engine starting and the quality of its operation, the quality of fuel, the level of environmental pollution, etc. You will not see standard iridium spark plugs in Russian-made cars, since there is no such thing in the country the necessary specialized equipment.

It makes sense to buy iridium kits only for owners of expensive cars with mileage exceeding 5 thousand km per year.

When you select a replacement for worn parts, you need to pay attention to the thread diameter, length and pitch, but the configuration of the wires may differ from what was in the original. You should also pay attention to the heat rating; if it is selected incorrectly, then either carbon deposits on the spark plug or detonation of the engine cylinders will occur. Soot on spark plugs occurs when energy leaks into the housing while the power between the side and center electrodes is weakened. Therefore, before purchasing, you need to rely only on the recommendations of the manufacturer of your vehicle.

A few words about

The mechanical engineering company was founded in Japan in 1949. Its main specialization is the production of components for cars: spark and glow plugs, magnetos, generators, starters, engine control systems, scanners, sensors, etc. Thanks to constant scientific and technical activities and its own advanced developments, Denso has become a world leader in production of electrical appliances. Concerns such as Volvo, Opel, Toyota, Subaru, and Citroen equip their cars with parts from this particular company. Denso subsidiaries are located in Japan, China, Taiwan, Singapore, Canada, USA, Brazil, Great Britain, France, Russia, Turkey, India, UAE, Morocco. The company's products are popular all over the world due to their quality and reliability.

How to choose candles

Denso iridium spark plugs should be selected based on the recommendations of your car manufacturer. How not to make a mistake when choosing, and most importantly, is there any point in such an expensive purchase? The main feature of spark plugs using iridium is the small thickness of the central electrode. This helps to better clean the spark plug from soot, which is always present in a running engine. The obvious benefit of high-tech spark plugs is that they need to be changed much less often, because this procedure is often quite difficult. But there is one “but”... It all depends on the quality of Russian fuel. It does not kill iridium spark plugs as quickly as regular spark plugs, but they often do not reach their full service life. Therefore, it only makes sense to buy iridium or platinum for owners of expensive cars whose annual mileage exceeds 5,000 km. There is no particular need to install iridium spark plugs on a VAZ, since they are quite easy to change on our cars, and the quality of Russian gasoline is different from European. Which iridium spark plugs are better? One of the main characteristics of a spark plug, regardless of its type, is its heat rating. The spark plug accumulates heat during engine operation. If the heat value is chosen incorrectly, then two scenarios are possible: detonation of the engine cylinders or fouling of the spark plug and its failure. Spark plugs have become almost a mythical attribute of the car, judging by what they write on car forums. The reality is that in Russia, ngk iridium spark plugs and other expensive spark plugs cannot withstand more than 50,000 km, although they are designed for a longer service life. The application of noble metals to the electrode increases the life of the spark plug and reduces the gap between the electrode and the insulator.

Features of Denso spark plugs

The Japanese manufacturer Denso is considered one of the leaders in the manufacture of components and consumables for automobile engines; this company produces:

cooling radiators;
electric fans;
stove motors;
starters, generators;
oxygen sensors;
windshield wiper blades;
ignition coils;
radiators for air conditioners;
glow plugs for diesel engines.

The Denso company has existed since 1949, and today it is one of the most successful enterprises in its field. The production of candles has been carried out since 1959, the concern is constantly developing original technologies, updating products, introducing new brands with improved characteristics. Denso candles are distinguished by a relatively low price, excellent workmanship, increased service life, the range of products offered is quite wide, and these are:

Iridium TT – spark plugs that guarantee stable starting of the internal combustion engine, reduced gasoline consumption, improved sparking, mileage on one set of artificial spark plugs up to 120 thousand km;
Nickel – parts identical to the original ones, have a heat-resistant nickel coating, ensure uniform heat dissipation;
Super Ignition Plug - spark plugs with very thin electrodes, have an extremely long service life, and are manufactured using the latest technologies;
Iridium Racing - AES developed for highly accelerated engines, allows you to achieve maximum acceleration of the car; Formula 1 technology is used for their production.

Denso's product range also includes the Double Platinum, Iridium Power/ Longlife/ Tough brand series, SZ are developed not only for cars, but also for water transport, motorcycles, and small-volume internal combustion engines.

NEGATIVE QUALITIES

The first thing that catches your eye is the high price of such candles. But given the long service life, high vehicle efficiency, excellent quality and temperature resistance, the price is justified, although it is higher than standard copper spark plugs.

Depending on the car model, iridium spark plugs may provide little or no performance improvement - it depends on the current state of the car. In addition, special engine efficiency is not always required and many vehicles will be limited to standard kits. Their use in conjunction with small-displacement engines is not recommended - such an expense will not be justified.

SERVICE

The operation of iridium kits has not changed over the past few years. They will still last over 100,000 miles on most cars, but manufacturers advise replacing them much more frequently, as frequent ignition, external contamination, and engine problems can reduce service life.

When choosing iridium spark plugs, the coincidence of the configuration with the old ones is not important, but the pitch, length and diameter of the thread must match, otherwise the installation will fail.

SPARK PLUG GAP – IS IT NEEDED TO BE ADJUSTED?

For some drivers, the issue of setting the gap is questionable. They can be understood, because the kits are produced with the gap set at the factory, and the engines of the cars are different. Still, there is no need to worry, because when we buy a kit for our model, we receive ready-made samples that only need to be re-adjusted when repairing the engine or cleaning the spark plugs themselves. For example, Denso products have a factory-set gap. Before installing new ones, it is recommended to check the spark plug visually for bent electrodes.

IS IT WORTH INSTALLING IRIDIUM PLUGS ON OLD CARS?

Is it worth installing iridium samples on old cars that have driven hundreds of thousands, or is it better to get by with a more budget option? This is a difficult question that cannot be answered unequivocally. The question here is, first of all, economic feasibility. On new injection models, expensive iridium options pay for themselves quite quickly. This happens not only due to improved technical characteristics of the engine, but also due to reduced maintenance costs, as well as a significant reduction in fuel consumption - and such spark plugs pay for themselves quite quickly.

An old carburetor car, regardless of whether it has iridium or regular spark plugs, will not “drive better”, and there will be no significant savings on gasoline. However, the operation of the ignition system will undoubtedly improve and become more stable, starting the engine in cold weather will be easier, and the engine will stop reacting violently to low-quality gasoline. Car maintenance is also important, especially one that runs on liquefied gas. Thus, installing modern spark plugs can significantly increase the comfort when operating a car, but it is unlikely that you will be able to save on the rest.

Iridium Tough

Denso iridium spark plugs of the Iridium Tough type are the most successful symbiosis of the company’s two technologies described above. A special feature of their design is a double needle-shaped side electrode made of a special platinum alloy. Its thickness is only 0.7 mm. It has a significantly less cooling effect on the spark, due to which a stable flame core is formed at the moment of ignition of the combustible mixture. The results of testing Iridium Tough spark plugs showed that this technology allows:

reduce fuel consumption by up to 5-7%;
increase the power of the power unit;
reduce the amount of harmful emissions.

As for the resource, they are designed for 100 thousand kilometers. They are completely universal, ideal for both gasoline and liquefied gas engines.