Best engine spark plugs 2021 — Denso, NGK or Bosch?

Spark plugs in a car are a device for igniting the fuel-air mixture in heat engines. In simple words, candles give a spark to the engine. Many auto mechanics advise changing spark plugs every 20,000 km, but some spark plugs can go 30,000 with you — everything is individual here. The condition of the candles says a lot — is everything in order with the engine. To do this, you just need to unscrew the candle and look at the carbon deposits on the electrodes. If it is uneven in color, then it is better to contact the service — by soot, the master will quickly diagnose your engine. Candles can be changed independently or in a car service, but first they need to be selected.

The range of auto products is always growing, and it is difficult for a simple driver to decide what to choose. In the ranking of the top 10 best spark plugs, we publish a selection of experts, the pros and cons of products.

Bosch FR7DCX

Our rating is opened by candles of domestic production, developed by qualified German specialists. This product is characterized by the fact that it is made of a rare alloy of nickel and yttrium, due to which the central electrode acquires high reliability. This ensures a sufficiently long period of operation of the product. Alloying of steel takes place automatically, due to which the build quality of each model is at its best. Yttrium allows you to increase the efficiency of ignition, in addition, this element allows you to reduce fuel consumption.

These spark plugs will not need to be changed too often, so they are best suited for vehicles that have difficulty accessing these products in engines. The model is perfect for many domestic and foreign brands, with its help you can fully unlock the potential of the engine. The electrode is quite thin — this allows you to reduce the wear rate and make the performance of the plug much higher. The distance between the electrodes is 0.9 mm — this is quite enough to ensure a stable spark and complete combustion of the fuel mixture in the cylinder. Not very suitable for automatic transmissions, the candle shows itself best in a manual gearbox.

Advantages:

• Durability;
• Versatility;
• The spark is stable;
• Good value for money;
• Acceptable cost.

Flaws:

• They do not show their capabilities very well in engines with an automatic transmission.

NGK BKR6EK (2288)

These spark plugs have two electrodes in their design, which is optimal for most types of engines. They are universal, that is, they are suitable for both automatic and manual gearboxes. However, some drivers of cars with automatic transmission complain that the momentum is not gaining too quickly. These are Japanese-made products, some car owners are not very flattering about them, but this is due to the fact that there are a large number of counterfeit products on the market, which is often almost impossible to distinguish from the original.

The cost of such products is quite acceptable, however, such spark plugs are characterized by a very long period of operation — about 30 thousand kilometers. Products have an iridium coating, this allows you to normalize the consumption of gasoline, regardless of its quality. If you fill the gas tank with high-octane fuel, the mileage can be doubled — up to 60-65 thousand kilometers. This option is optimal for drivers who seek to ensure stable and proper engine operation, especially at medium speeds.

Advantages:

• Can be found in almost every auto parts store;
• If the products are original, then the quality is on top;
• The spark is very stable;
• Long period of operation;
• Great option for a relatively new engine;
• Possesses a reliable insulator of the central electrode. Even with high mileage, it will not crack.

Flaws:

• There are a lot of counterfeit products on the shelves;
• These spark plugs are quite sensitive to fuel quality.

NGK

When it comes to various tools and devices of their car, motorists approach the choice with all care, because safety depends on them. Talking about the company NGK She is an innovator in the spark plug industry.

It is known that 87% of shareholders today choose NGK products when it comes to finding parts for a vehicle. The company’s candles are even installed in Formula 1 cars. The brand produces wiring, glow plugs, ignition coils, spark plugs and more.

Pros:

• long-lasting candles;
• quality;
• packaged in a cute box.

Minuses:

• starting at -30°C can be problematic;
• price.

Denso PK20PR-P8

They are among the best in terms of wear resistance — the manufacturer managed to achieve this effect largely due to the use of plastic soldering. It is present on both the center and ground electrode. The manufacturing technology is fully automated, spark plugs are made in Japanese factories. Quality control is very strict. The design provides for two electrodes, due to which the engine can be ignited even in the event of a low level of positive charge. Such candles are perfect for Russian conditions, as the engine will easily start even at low temperatures.
The use of platinum coating allows you to achieve another important positive effect — candles resist well the occurrence of erosive and corrosion processes. Platinum increases the resistance to mechanical stress. Such candles can reduce fuel consumption; on sale you can find products designed for many makes and models of engines.

Advantages:

• Long period of operation;
• High quality workmanship;
• Acceptable cost.

Flaws:

• For Renault cars, the gap between the electrodes is not very suitable.

SCT

firm SCT many are interested, because it is at the hearing. The company was founded in 1993 and currently cooperates with manufacturers around the world. In the assortment of the brand you can find not only high-quality spark plugs, you can also buy auto chemicals, various filters, oils, etc.

In Russian operating conditions, spark plugs proved to be more than worthy. They are designed in such a way that they fit almost all brands of cars. SCT spark plugs are divided into 4 groups: SCT Perfect, SCT Classic, SCT Platin and SCT Tuning. Classic can be found for almost any car.

Pros:

• reliable brand;
• quality;
• candles do not darken over time.

Minuses:

• marriage may occur.

NGK LZKR6B (1578) LZKR6B-10E

The model is distinguished by the presence of a nickel electrode, which is responsible for the constancy of work and a long service life (up to 30 thousand kilometers). Candles are suitable for most passenger cars of Russian and foreign production.

NGK LZKR6B (1578) LZKR6B-10E

Due to the increased sparking, candles quickly ignite combustible mixtures, which has a positive effect on the starting performance of the engine. Side electrodes improve even wear distribution.

Characteristics:

• thread diameter: 12mm;
• gap width: 5 mm;
• heat number: 6;
• side electrodes: 1;
• central electrode diameter: 6 mm;
• resistor: 10 kOhm.

pros

• universality;
• independence from climatic conditions;
• reliable sparking;
• compliance with price and quality;
• long period of operation.

Minuses

• the opportunity to purchase a fake at the price of the original.

Beru Z193

This is a kind of classic of the genre and is popular with buyers. Candles confidently serve their term from one MOT to another, do not let the owner down, but at the same time they do not amaze with excellent results. The thread length is 19 mm and the tightening torque is 25 Nm. The design is single-electrode, due to which the service life is noticeably reduced. The average cost is only .

Beru Z193 spark plugsAdvantages:

• The price is available to every car owner;
• Counterfeiting on the market is minimal.

Flaws:

• The minimum spark gap reduces the power of the spark produced;
• The ventilation of the spark gap is reduced due to the work of the central electrode, which is «recessed».

Brisk

Brisk — quite decent spark plugs for an adequate price. They do not have any remarkable features — typical candles, however, they show themselves very well in work. As a result of testing, it was revealed that the candles «ran» more than 20,000 km.

Brisk was founded in 1935 by a leading Czech manufacturer of spark plugs. The product range includes not only candles, but also technical ceramics, ignition electrodes, sensors, etc.

Pros:

• package;
• appearance;
• quality;
• low price;
• good resource.

Minuses:

• not suitable for all cars.

Bosch W7 DTC Standard Super

A good increase in fuel economy (3.2%) Country: Germany (produced in Russia) Average price: . Rating (2020): 4.9

An interesting version of spark plugs from a German manufacturer, which gives a maximum increase in fuel economy compared to single-electrode analogues. Possessing, in general, a standard structure inherent in almost all candles from Bosch, the W7 DTC Standard Super presents some very pleasant “surprises” revealed during complex tests. The pressure test carried out in the pressure chamber, the model passes perfectly, demonstrating good spark stability. At maximum throttling, the increase in power is not so noticeable, but there are positive trends — relative to single-electrode EZ candles, it amounted to 2.3-2.7%.

However, the Bosch W7 DTC Standard Super was most successful in the consumption component. A decrease of 3.2% is an excellent result, especially for engines that are far from the first freshness. These candles are well bought up by the owners of LADA, Chevrolet and VAG-group cars.

NGK BKR6EIX (6418)

Iridium spark plugs from NGK are noticeably superior in workmanship to their counterparts of a conventional design, but in terms of parameters they still do not meet the requirements of Renault: here the interelectrode gap is only 0.8 mm. It makes sense to install such candles on a new engine that does not have noticeable oil consumption — in this case, the reduced clearance, combined with the spark stability provided by the central electrode with a diameter of less than a millimeter, guarantees starting even on a thoroughly discharged battery.

With a careful choice of gas stations, iridium candles have a decent resource, which can reach up to 50,000 kilometers. People who often travel far by car in different directions should better think about purchasing two sets of ordinary candles for the same money — it is not the best option to make an expensive set of candles unusable by random refueling.

Main advantages:

• stable sparking;
• potentially high resource.

Minuses:

• inaccurate compliance with factory clearance requirements;
• the highest price of the considered candles.

The best iridium candles

Now the most efficient and durable ignition systems are Denso products. For the first time, Denso spark plugs were used in serial production in 1997.

Denso itself claims the following advantages: high degree of insulation using aluminum oxide, low electrical losses. Denso products should be selected taking into account the recommendations of car manufacturers. Convenience is added by the fact that the candles have an exposed electrode gap. The widest selection of car brands and the best quality put Denso at the top of the list of ignition systems.

Bosch Platinum WR7DP

The WR7DP has a unique design that maintains a powerful spark regardless of the voltage. The reason lies in the thin core, located on the same level with the ceramic insulator.

Bosch Platinum WR7DP

Candles perform their functions for 60 thousand kilometers. Resistance to climatic features and carbon deposits is explained by platinum plating, which acts as a protective layer.

Characteristics:

• thread diameter: 19mm;
• gap width: 0.8mm;
• heat number: 7;
• side electrodes: 1;
• central electrode diameter: 0.3 mm;
• resistor: 5 kOhm.

pros

• high quality assembly materials;
• original structure of the central electrode;
• no interruptions in operation at low voltage;
• a large number of modifications for different cars;
• long service life.

Minuses

• increased fuel consumption;
• numerous forgeries.

Best Inexpensive Single Electrode Spark Plugs

Bosch WR7DP

Bosch WR7DP

Unique, in terms of the design of the central electrode, a candle. The thin core is made almost flush with the ceramic insulator, due to which the spark takes on the appearance of a plasma discharge. This discharge is stable even at low voltage in the car’s on-board network. When working on high-quality fuel, the resource of one candle is almost 55-60 thousand kilometers — this indicator is achieved due to platinum plating. However, domestic roads do not recognize precious metals. In Russian realities, Bosch WR7DP candles burn out much faster. They are installed mainly on foreign cars, such as Chevrolet, Hyundai, Nissan, etc. The price is above average, but iridium counterparts are much more expensive.

Advantages:

• innovative design of the central electrode;
• a spark of a kind of plasma arc;
• attractive price;
• stable operation at low battery voltage;
• the presence of modifications for cars VAZ, Renault, Chevrolet, etc.

Flaws:

• fuel consumption is slightly higher than when using regular (saving) spark plugs.

Denso W20EPR-U

Denso W20EPR-U

Denso W20EPR-U is positioned as a standard spark plug designed for use in engines of LADA, Chevrolet, Nissan and Daewoo vehicles. It contains several interesting design solutions at once, thanks to which it opens up new facets in working with stock engines. First, it should be noted the original shape of the ground electrode with a U-shaped groove. This decision made it possible to slightly increase the area of ​​flame propagation from a spark, increasing the completeness of combustion of the air-fuel mixture and reducing emissions (by an average of 3.1% compared to EZ candles). Secondly, the core of the central electrode was replaced from solid nickel to copper, which made it possible to slightly increase the power of the engine, as well as slow down the wear of the side electrode. However, it is worth recognizing that the working life of the Denso W20EPR-U (even despite the improvements) turned out to be not the largest — at best, such a candle is enough for 30 thousand kilometers.

Brisk Premium LOR15LGS

The Brisk Premium LOR15LGS pleases motorists with brilliant performance and engineering that is not quite typical. The shape of the side electrodes of this device is unusual, but the fact is that they “look down”, that is, they are lowered along the rod. Because of this, the sparks produced «surround» the main electrode along the entire length of the exposed part. Due to this, the fuel-air mixture is ignited at the primary stage of supply to the combustion chamber. This action saves fuel well, which is a definite plus for any driver. The price is about .

spark plugs Brisk Premium LOR15LGS Advantages:

• Non-standard form of electrodes;
• dense spark;
• Fuel economy;
• Long operation.

Flaws:

• «Bite» cost.

Rating of the top 9 best spark plugs for a car according to KP

In this rating, we will tell you about each candle in more detail — with pluses and minuses.

NGK 4559 TR5B-13

Spark plug NGK 4559 TR5B-13 . Photo: yandex.market.ru
These French spark plugs from NGK guarantee fast engine start, increased engine power and high quality. Despite the low price, these spark plugs are of very high quality and are suitable for all gasoline engines. The manufacturer notes that the candles are special in that they provide stable sparking, the fuel-air mixture will ignite better and burn efficiently.

high quality at low cost, fast engine start and economical consumption, durable

not suitable for all vehicles

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Bosch SuperPlus FR8HDC

Spark plug Bosch Super Plus FR8HDC. Photo: yandex.market.ru
Bosch again, this time with Super Plus FR8HDC spark plugs. These spark plugs are also suitable for gasoline engines. The central electrode of the candle is made of yttrium and nickel — thanks to this, the candles have a longer service life (the alloy of these elements is highly wear-resistant and also guarantees ignition reliability). Candles, according to the manufacturer, protect the catalyst and save fuel in the car. Drivers note that candles radically change the operation of the engine for the better, the engine runs cleaner. Cars can travel up to 50,000 kilometers on these spark plugs.

wear-resistant due to the alloy, save consumption, do not clog

you can easily run into a fake

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DENSO 5303 IK16

Spark plug DENSO 5303 IK16. Photo: yandex.market.ru
The DENSO brand is quite popular in the auto parts market. The center electrode of these spark plugs is made of iridium and is suitable for gasoline engines. The manufacturer refers to the advantages of a thin electrode — only 0.4 mm, improved flammability and improved acceleration. Users noted that in winter the car starts better and faster. Others have noticed a reduction in consumption.

thin electrode, improved acceleration, wear-resistant

easy to get fake

BRISK DR15YC-1

Spark plug BRISK DR15YC-1. Photo: yandex.market.ru
Another popular brand in the candle market is BRISK. The central electrode of the DR15YC-1 spark plugs is made of a nickel alloy with a copper core. Candles behave well both in city slow driving, and on the highway, at higher speeds and in other driving modes. They are suitable for almost all cars — however, there are always exceptions, it is better to check with a consultant if they are suitable for you. The stated replacement interval is 30,000 km.

fit almost all cars

the maximum change interval is 30,000, while others have these numbers much higher

NGK 4339 DCPR8E

Spark plug NGK 4339 DCPR8E. Photo: yandex.market.ru
This candle has a trivalent metal coating — it gives reliable protection against corrosion. There is also a corrugated ceramic insulator that provides good heat dissipation. Thanks to it, a spark will also not form outside the electrode zone. The core of the candles is copper, it perfectly removes heat, the manufacturer claims. Motorists will get high quality for low cost.

high quality for low cost, anti-corrosion treatment

some users have noticed that the service life is lower than stated

NGK 6899 CPR6EA-9

Spark plug NGK 6899 CPR6EA-9. Photo: yandex.market.ru
The manufacturer highlights several features of the NGK 6899 CPR6EA-9 candles. They have nickel side and center electrodes — this ensures uninterrupted operation and stable sparking. Also, this mixture will provide improved ignition of the fuel-air mixture and efficient combustion. Motorists have noticed a slight improvement in fuel economy. Buying candles of this brand, you get high quality for a low cost.

trouble-free operation, stable sparking, saving consumption

some users have noticed that carbon deposits sometimes appear on the candles

Bosch SUPER 4 WR78

Spark plug Bosch SUPER 4 WR78. Photo: yandex.market.ru
The next model from Bosch is the SUPER 4 WR78. This is one of the popular models on the market. The candle has four side electrodes, the central one is silver plated. The manufacturer claims that the candles are self-cleaning from soot. The engine starts quickly and confidently even in cold weather, works flawlessly, is able to drive over 50,000 km. The electrodes are made of chromium-nickel alloy with a copper core. The long service life of the candles is explained by the fact that the candles wear out evenly — with the Bosch SUPER 4 WR78 there will be no such situations that one of the candles fails while the others work.

fast engine start, self-cleaning from carbon deposits, long service life

some motorists noticed a slight increase in fuel consumption, a high probability of running into a fake

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DENSO 4702 IK20TT

Spark plug DENSO 4702 IK20TT. Photo: yandex.market.ru

These are candles that have many features. They are made of iridium, suitable for gasoline engines.

The manufacturer notes that the service life of the candles has been significantly increased — the car can drive up to 120,000 km before replacing the candles. The «Japanese» have improved sparking to the maximum, candles contribute to fuel economy and reduce harmful emissions.

motorists note that the engine has become quieter, consumption and detonation have slightly decreased under load. There are also improvements in dynamics

despite the high quality of candles, motorists attribute the high price to the minuses

Brisk Silver LR17YS

Spark plug Brisk Silver LR17YS. Photo: yandex.market.ru
These candles have a high thermal conductivity of silver, an excellent shape of the electrodes and a small distance between them (0.55 mm 0.7 mm and 0.9 mm). Candles guarantee perfect burning of the mixture, so candles are used even for powerful racing cars — this indicates the high quality and wear resistance of the candles. The stated replacement interval is 45,000 km.

wear resistance, high thermal conductivity of silver

the maximum change interval is 45,000, while for others these numbers are much higher

NGK LPG Line №2

The best candle for gas engines Country: Japan Average price: . Rating (2020): 4.9

NGK LPG Line No. 2 is the main candle for installation on gas-equipped engines, occupying more than 90% of this market. Having entered such a specific niche, NGK began the most large-scale, comprehensive development of spark plugs, taking into account all the nuances and specifics of natural gas combustion. This approach made it possible to find the most correct geometry of the central iridium electrode, as well as to regulate the gap between it and the side electrode with platinum surfacing.

Such heterogeneous materials were also not chosen by chance: given the different composition of the combustible mixture, as well as operating modes, the electrodes needed additional protection and stimulation of work without misfiring. In this regard, it was possible not only to maximize the volume of combustible fuel, but also to increase engine power by 3-4%. Such a model is quite expensive, but it “lives” unlike its competitors.

The main signs of failure of the candle

The appearance of spark plugs can tell not only about their work, but also about malfunctions of both the fuel system and other engine systems. What are the signs of a bad spark plug?

So that drivers can understand from the behavior of their car that it is time to replace the spark plugs, let us recall the main signs of their malfunctions:

• misfiring and engine tripping;
• the smell of gasoline;
• increased fuel consumption;
• deterioration in dynamics;
• glow ignition;
• brown color and cracks at the bottom of the insulator.

Denso PK20PR P8

One of the best candles made in Japan. It is resistant to wear and is suitable for both 16 and 8-valve engines. The effect is achieved due to soldering, which is installed on all electrodes. During production, the latest technologies are used, accompanied by an automated process.

The design consists of two electrodes, the location of which allows you to create a stable spark. The internal combustion engine is able to start even with a low battery charge. Denso PK20PR P8 is suitable for passenger cars, four-stroke walk-behind tractors and other agricultural machinery. This is the optimal solution for harsh climatic conditions, the improved anti-corrosion coating allows the candle to function even in severe frost or high humidity. The electrode material is platinum and yttrium.

Advantages and disadvantages long service life; price; high build quality and internal components; the presence of a plastic insulator. The spark gap is not suitable for all cars.

How to change candles and what to do when a candle thread is torn off

Maintenance comes down to a visual inspection (checking with a spark probe and a gap with a probe) or a preventive replacement according to the instructions for the car (in Soviet times there were also collapsible glow plugs) with a run of 20-60 thousand km.

Leaded gasoline, cylinder-piston failures and difficult conditions (congestion, increased loads) can reduce the life of the kit. At the same time, cases of work over more than 100,000 kilometers are known.

A few practical recommendations.

• Replace only on a cold engine — tightened «from the heart» on a warm one will subsequently be difficult to unscrew.
• You should not exceed the recommended tightening torque — the threads are thin, and the block head is usually aluminum. For accurate dosing of torque, a torque wrench is useful.
• To make it easier to change next time — draw a pencil along the threaded part — graphite will not allow it to «stick» during operation.

If you overdo it and damage the thread, use a thread repair kit with a “spring” or a screw driver (futorka). If you have experience, you can do without removing the cylinder head — repairs will take less than an hour.

NGK CR9EK (4548)

Model CR9EK (4548) guarantees a powerful spark that can easily ignite lean fuels. Thanks to this factor, the operation of the engine is stabilized under any conditions.

NGK CR9EK (4548)

Grounded electrodes are responsible for the constant formation of sparks, regardless of the amount of carbon deposits formed, which allows them to be used even with cheap fuel. The built-in resistor prevents radio frequency interference from affecting the electronics.

Characteristics:

• thread diameter: 10 mm;
• gap width: 0.7 mm;
• heat number: 9;
• side electrodes: 2;
• central electrode diameter: 2.5 mm;
• resistor: 5 kOhm.

pros

• absence of sparks outside the working area of ​​the electrodes;
• protection against corrosion and erosion;
• high-quality work with fuel of any quality;
• RF interference protection;
• good quality materials.

Minuses

• some users consider the price too high.

Which brand of spark plugs to choose?

There are different types of candles on the market today. They are differentiated according to various criteria, for example, use in gasoline or diesel engines. There are also differences related to the number of electrodes (two and multi-electrode) and the material (iridium, platinum) from which they are made.

The most popular models belong to brands such as:

• NGK. The brand successfully cooperates with such business sharks as Ferrari, BMW, Volvo, etc.
• Bosch. Supplies parts for Mitsubishi, Toyota, Audi, Fiat.
• Brisk. Creates consumables for BMW, Skjoda, Opel and Audi.
• champion. Has a contract for the creation of auto products for Alfa Romeo, Suzuki, Jaguar and other brands.
• Denso. A well-known Japanese corporation that creates high-quality spare parts for various cars.

Purchasing spark plugs from these companies will be a great savings and an excellent alternative for any brand of your car. The quality of the products is excellent and appreciated by many professionals.

Clearly about spark plugs:

Which spark plugs are higher rated by PR

Choosing among analogues of this spare part, buyers want to know which manufacturers are recommended by car owners. In November 2021, the TOP 5 spark plugs with the highest ratings on PartReview were as follows:

1. MOTRIO — 96% positive votes. Average score — 4.4
2. Autolite — 93% positive votes. Average rating — 4.3
3. WEEN — 89% positive votes. Average rating — 4.3
4. OEM Renault — 87% of positive votes. Average rating — 4.2
5. Torch — 86% positive votes. Average rating — 4.2

Types of spark plugs

Candles are divided into several types depending on the materials and mechanism of operation. Candles, which are most often found in the automotive market, are presented in the table.

Table 1. Types of spark plugs

KindCharacteristic

single electrode	They consist of two parts — a ceramic body and a metal glass. The spark is generated due to the interaction of the central and ground electrodes. The mechanism has a low price, but has a limited period of operation
Multielectrode	The structure of the candle includes one electrode located in the center and three or four electrodes on the sides. An increase in the number of conductors leads to an increase in the wear resistance of the product. The disadvantage of this mechanism is the difficult ignition of the fuel.
Nickel	Nickel is the material that is used in the creation of most budget candles. Its main advantage is low price and stability of work. The disadvantage of nickel structures is the limited service life. Candles will last from 15 to 50 thousand kilometers
Platinum	Platinum is one of the noble metals and is characterized by its resistance to high temperatures. The use of this material in the creation of thin electrodes has led to an increase in the stability of the engine by increasing the power of sparking.
iridium	Iridium surpasses platinum in melting point and resistance to extreme temperatures. It is not characterized by destruction under the influence of chemicals and erosive processes. The main advantage of candles is the constancy of work over a wide range of loads and the efficiency of fuel combustion.

Video — How to choose candles for your car

The best premium single electrode spark plugs

Denso PK20PR-P8

Denso PK20PR-P8

Very common candles among owners of cars of the Nissan B platform (Renault, Nissan, VAZ). They liked it for a high indicator of a working resource (about 40 thousand kilometers on fuel of not the highest class) and for the corresponding low cost. In terms of quality, Denso PK20PR-P8 is also all right: Japanese manufacturers, as they say, did a great job on platinum coating and electrode geometry. The only problem during operation can be a small interelectrode gap, made so for the sake of sparking even at low mains voltage. Nevertheless, motorists are not at all embarrassed to purchase these candles, fortunately, in the vast majority of cases, the purchase becomes completely justified.

Advantages:

• acceptable working resource;
• good quality electrode coating;
• the presence of typical iridium analogues (more expensive, but more resistant).

Flaws:

• insufficient, based on regulatory requirements, the interelectrode gap for Renault cars and the like (0.8 mm).

NGK BKR6EIX

NGK BKR6EIX

Iridium spark plug with long working life. According to numerous users, one set is enough for an average of 50 thousand kilometers, however, when using high-quality high-octane fuel, this figure can increase to 60-65 thousand kilometers. In terms of fuel economy, there is no particular difference with inexpensive candles, however, the economic factor is expressed by working out the entire period of the declared operation.

The cost is high, due to the iridium coating applied to the central and only side electrode. The best option for drivers of German (BMW, Audi, Volkswagen), American (Ford, Chevrolet, Chrysler) and Japanese (Lexus, Toyota, Mazda, Honda») brands that are very interested in the stable operation of the engine.

Advantages:

• widespread;
• long service life (about 50 thousand kilometers);
• iridium coating;
• stable spark;
• high nominal quality.

Flaws:

• high cost offset by quality and durability.

Heat number, cold and warm candles

The glow number indicates the pressure in the cylinders at which spontaneous ignition of the fuel mixture from a hot candle occurs. The appearance of such a glow ignition adversely affects the operation of the engine, leads to a loss of power and an increase in fuel consumption. Such spontaneous ignition of the fuel-air mixture leads to an increased load on the piston group, which in turn reduces the engine life. Many car owners are wondering if spark plugs are cold hot, what’s the difference. This concept directly depends on the heat number.

It is the glow number that determines the thermal operating conditions of the candle. Accordingly, the higher this indicator, the more difficult conditions a particular spark plug is able to work. That is why it is necessary to take into account this characteristic and compare it with the performance of a particular internal combustion engine. It is customary to subdivide cold and hot spark plugs, the difference between which is the glow number. As you can understand from the name, cold candles heat up slowly, and subsequently quickly dissipate the resulting heat. Hot spark plugs, on the contrary, heat up quickly, but at the same time, such devices themselves slowly dissipate heat.

Hot plugs are recommended for use in engines that operate at standard crankshaft speeds. In such power units, candles are not subjected to serious temperature loads, which makes it possible to ensure trouble-free ignition and the absence of spontaneous ignition of the mixture. Popular are self-cleaning hot plugs, in which such cleaning is carried out at relatively low temperatures, which improves the flammability of the fuel mixture.

But cold spark plugs are characterized by increased resistance to temperature loads and are recommended for use in turbocharged and forced power units. Self-cleaning of such candles occurs at high temperatures, so it is not recommended to install them in conventional atmospheric non-forced engines. In atmospheric engines, the temperature regime will not allow cold candles to self-clean, which will lead to ignition problems. Most manufacturers recommend the use of these types of cold plugs with premium cars and sports cars that have uprated and turbocharged engines that operate with a high temperature load.

We light a candle, but what kind? What to choose when you need to change spark plugs

The spark that has broken through the gap between the electrodes of the spark plug not only sums up all the preparatory processes that take place in the engine for three cycles before the ignition of the combustible mixture in the cylinder. From what kind of spark there will be and whether there will be at all, it largely depends on how the most important cycle will pass, at which the heat released during combustion should turn into mechanical energy.

A candle can fail for various reasons. Whatever they may be, the consequences of a malfunction, which include the absence of a spark or its insufficient strength to ignite the combustible mixture, will necessarily affect the operation of the engine, and may also cause premature failure of other components of the ignition system: coils, high-voltage wires. In addition, there is a risk of damage, for example, to a lambda probe and a catalyst located after the engine in the exhaust tract, where unburned gasoline ejected from the cylinder will burn out.

This explains why spark plugs are recommended to be changed in advance, without waiting for problems, and the replacement frequency is specified in the maintenance schedule. At the same time, it is not a fact that the owner will find in the instruction manual that comes with the car which candles should be used. And what to do if the car has changed owners several times, the manual has been lost and it is not clear whether the candles for which a replacement is being sought are recommended or were supplied by the previous owner from the «balda»?

Information about candles is contained in the maintenance and repair instructions, but in order to get instructions, you need to take the initiative, and the information in them is ambiguous. Some models of candles are recommended by car manufacturers, some are allowed for installation, and the choice of brands, as a rule, is limited only to partner ones, but only on them the light has not converged like a wedge.

From offers of candles of other brands with the same mounting dimensions and characteristics, the eyes run wide. Trademarks — from no less eminent than recommended by the car manufacturer, to «dark horses», and the darker the «horse», the more attractive its price. What should be considered in such a situation?

From the information, including the information obtained during a trip to a candle factory in Germany and in conversations with representatives of other manufacturing companies, we can conclude that correctly selected candles for the engine must satisfy only two conditions. Firstly, in any of the operating modes, the candles must not overheat above 850 ° C and cause glow ignition, or, in other words, begin to ignite the combustible mixture with an electrode hot from overheating even before a spark appears.

Therefore, the glow number, which characterizes the ability of the candle to work without glow ignition, is the main parameter of the candle, which is necessarily reflected in the number in the product marking.

Unfortunately, there is no single standard for the heat number, so manufacturers label products according to their own standards. However, interchangeability tables for the glow number of candles of various brands are available, so no difficulties are foreseen with the selection of this parameter.

The ability to self-clean from soot is the second fundamental condition that candles must satisfy. In order for the soot to burn out intensively, and for the candle to self-clean, it is necessary that the parts of the candle on which the soot is deposited are heated to at least 450 ° C. If you had to deal with electrodes overgrown with soot, it may turn out that the candles do not meet the requirement precisely in terms of self-cleaning ability.

At first glance, with this characteristic, not everything is as simple as with the glow number. Adding fuel to the fire is that many owners know that candles come in «cold» and «hot». The type of candle determines how it self-cleans.

I must say that in themselves these definitions are again not standardized and relative. Conventionally, “cold” refers to candles, in which heat removal from heating elements is better organized. In «hot» candles, heat removal is worse, therefore, unlike «cold» ones, they are more effective in self-cleaning from carbon deposits, but they are prone to glow ignition when working in engines with intense thermal conditions.

“Cold” candles, of course, have a different problem. During engine operation at low coolant temperatures, during short trips and long stops between trips, such candles may not have time to self-clean and will become overgrown with soot.

On the one hand, all this just demonstrates how important the choice of candles is for a particular engine. On the other hand, how to understand whether a candle belongs to a “cold” or “hot” type, if one of the letters in the candle marking can indicate belonging, and for each, where should it be placed in the sequence of other letters and should it be placed at all?

Some experts recommend paying attention to how the thermal cone of the ceramic insulator of the central electrode is recessed in relation to the metal part of the housing. There is a certain sense in this — “hot” candles really have a longer thermal cone, and, by the way, it is the indication of the protrusion of the cone that may be present in the marking. However, this is not the main thing.

More importantly, what is not visible to the naked eye. Even 20 years ago, or maybe more ago, the desire to combine the properties of “hot” and “cold” candles in one design led to the development of a bimetallic central electrode with a chromium-nickel shell and a copper core, which conducts heat much better than the shell. Such candles quickly heat up to the self-cleaning temperature, but upon further heating they do not cause glow ignition, which is why they are wide-range in terms of temperature characteristics.

Such are many modern quality candles. Therefore, now things are not so terrible with the determination of the ability of certain candles to self-cleanse. The main thing when choosing is to avoid «dark horses», no matter how tempting the price is, and when buying products from famous brands, do not run into a fake. Thus, only compliance with the incandescent number and, of course, the overall and mounting dimensions will remain.

The use of precious metals in candles, as well as constructive «frills» such as several side electrodes, additional surfacing of small diameter on the electrodes, U-shaped recesses and V-shaped cuts on the electrodes, and the like, in most cases, is aimed at increasing the service life of the candles themselves and other components ignition systems, as well as improved combustion efficiency.

The more refractory platinum, yttrium, iridium and its alloy with rhodium are superior to chromium-nickel alloys in erosion resistance. Refractoriness allows, without sacrificing durability, to reduce the diameter of the electrodes, and therefore, to reduce the voltage required to breakdown the claim gap, and with it, the load on the ignition coil.

In addition, the thinner the electrodes, the less interference with the development of a flame ignited by a spark. By the way, multi-electrode candles sin with such a disadvantage, the side electrodes of which, after ignition of the mixture, shield the flame front, preventing its spread and, as a result, complete combustion of the mixture.

Therefore, while spreading the thermal load across multiple electrodes does increase the reliability and life of multi-electrode spark plugs, the power and emissions of an engine equipped with them can be degraded compared to what the same engine exhibits when single ground electrode plugs are installed. .

Under conditions of operation on gasoline of non-guaranteed quality, multi-electronic spark plugs revealed a much more significant drawback, which can lead to engine breakdown. We talked about this in the articles “Why did the electrodes fall out of the spark plugs?”, Which can be found here and here.

The foregoing explains why individual service stations avoid using multi-electrode candles in their work, preferring ordinary ones, in which the central electrode rests against the side electrode in such an opportunity and cannot fall out.

When choosing technologically advanced spark plugs, be aware that the extra «bells and whistles» add to the cost, but this increase is not always offset by longer life and other benefits. If, as an example, we turn to the NGK candles mentioned in the photo posted above, then buying the recommended BKR5ES-11 will cost 4-4., and the platinum PFR5N-11 allowed for installation will cost 13-14.. depending on the place of purchase. It is not certain that a positive answer to the question whether PFR5N-11 will last more than three times longer than BKR5ES-11 will be confirmed in practice.

Finally, it is worth recalling that the state of the thermal cone and the electrodes of the spark plugs, which began to create problems during operation, may suggest that not everything is fine with the engine. For example, black oily soot is a sign that the spark plug is being flooded with oil, which breaks into the combustion chamber through worn piston rings, guide bushings, or valve stem seals. Matte black soot has other causes — too rich a mixture or late ignition.

And the notorious glow ignition may not be the result of the wrong selection of candles, but the result of setting an early ignition timing, excessive depletion of the combustible mixture, or something else. However, motor problems and their impact on the performance of candles is a completely different story.

Sergey BOYARSKIKH Photo by the author and from open sources ABW.BY

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Precious Candles. Iridium and platinum

Electrodes made of rare earth precious metals — platinum and iridium — are five times thinner than nickel ones. And five times more reliable: ordinary candles last about 20 thousand km, and «precious» — about 100 thousand. True, the cost of such candles is 4-5 times higher, but you will significantly save on the work of replacing them.

Platinum was the first rare earth metal to be widely used in spark plugs. Platinum overlays on the central and side electrodes significantly reduced the wear of the electrodes and increased the life of the plug. The thickness of the platinum spark plug electrode was reduced to 1.1 mm, which significantly reduced the voltage required for the spark, and hence the load on the ignition coils.

Iridium spark plugs are a more modern development. The diameter of the central iridium electrode was brought to a record 0.4–0.6 mm, which ensured outstanding combustion of the mixture in the cylinder and an increase in engine efficiency. Iridium is almost an order of magnitude superior to nickel in thermal conductivity, which helps to lower the temperature of the electrode. For modern cars, most manufacturers recommend iridium spark plugs.

Expert’s Choice

Bosch ZR5SI332 Platinum Iridium

Spark plug Bosch ZR5SI332 Platinum Iridium. Photo: yandex.market.ru

Our rating opens with a spark plug from Bosch — ZR5SI332 Platinum Iridium. Its central electrodes are treated with platinum-iridium alloys. Due to this, it has a very high wear resistance and resistance to various influences, including chemical ones. The central electrode of the spark plug is only 0.6 mm in diameter — this guarantees good flammability.

spark plugs guarantee trouble-free ignition, they are resistant to corrosion

not suitable for diesel engines

Replacement table for candles from various manufacturers

Russia	Bosch, Germany	Champion,England	Motorcraft, USA	NGK,Japan
A11	W8A; W9A; W8AP;W9AP; W8AC;W9AC	L88A;L88	AE52	V5HS
A14DA17DV	W6CCW7DC; W7DP; WR7DC;	N5N10Y	AG3; AG31AG252	BP6ES
A17DV-10	WR7DPW7DC; W7DP; W7DTC;WR7DP; WR7DC	N9Y	AG252	BP6ES
A20D1;A20D2	W6CC	N3	AG4	B7ES
A23	W5A; W5AP;W5AC	LW81;LW82	AE2;AEZ	B7HS

Tips & Tricks

It should be noted separately that the manual for the car contains a list of spark plugs that the manufacturer recommended at the time of production of the vehicle. Over time, the situation may change and the list of candles that are suitable in terms of parameters often turns out to be extended. To simplify the selection, there are special tables of interchangeable spark plugs, which must be available from sellers or presented on the websites of online stores.

It should be added that special services have been additionally implemented on the Internet that allow you to quickly select spark plugs by make and model of a car online. For selection, you will need to specify the car model, VIN code and engine size. Often, services will offer several suitable options for the specified vehicle model at once.

With the seeming simplicity of selecting spark plugs by car brand, before buying, you should make sure that the package with new elements contains a separate list of models that allow the use of these candles. We also advise you to pay attention to the reputation of the seller (especially in the case of purchases in online stores). The fact is that today there are a large number of low-grade fakes on the market.

Carefully inspect the set of purchased spark plugs, and also pay attention to the packaging. The candles themselves should not have chips on the insulator, damage to the electrodes and other defects. If you purchase a new kit in car dealerships or retail outlets, check the possibility of checking the performance of spark plugs on a special testing stand. Such equipment must be available from a reputable dealer.

Finally, we add that the selection of spark plugs for cars with LPG requires a separate approach. When choosing, it is necessary to consult with specialists who install gas equipment on a car, and also ask the seller of candles to pay special attention to this issue.

Denso

Brand Denso produces not only spark plugs, the range is also replete with oil filters, fuel pumps and much more. For many years, Denso has steadily maintained its leading position in the market. The company was founded back in 1949.

All spark plugs are produced according to the quality standard, the products are constantly updated, which can please motorists. These Japanese candles are time-tested — during testing, 18,000 km were covered on them — everything is fine.

Pros:

• price;
• quality;
• durability;
• reliability.

Minuses:

• there are fakes.