Which spark plugs are better

The ignition of the air-fuel mixture in internal combustion engines occurs with the help of a spark produced by devices called spark plugs. The stability of the operation of the power unit depends on their quality and condition.

A voltage of several kilovolts to several tens of kilovolts is applied to the electrodes of the spark plug. The short-term electric arc that occurs in this case ignites the air-fuel mixture.

Due to faulty, exhausted spark plugs, spark failures occur, which leads to unstable engine operation, loss of power and excessive fuel consumption.

Therefore, from time to time, spent candles have to be changed. To determine the frequency of replacement, you can focus on the mileage or on the behavior of the motor.

Commercially available spark plugs may differ in design, metals used in the electrodes, and some other parameters. Let's try to understand this and determine which of them is better.

What kind of spark plugs are there?

In the classic version, the spark plug is two-electrode – with one central electrode and one side electrode. But due to the evolution of the design appeared multi-electrode (there may be several side electrodes, mostly 2 or 4). Such multielectrode allows to increase reliability and service life. Also less common due to their high cost and conflicting tests flare и prechamber candles.

In addition to the design, candles are also divided into other types, due to the material used to manufacture the electrode. As it turned out, often this is steel alloyed with nickel and manganese, but to increase the service life, various precious metals are soldered onto the electrodes, usually from platinum or iridium.

A distinctive feature of platinum and iridium spark plugs is a different form of the center and ground electrodes. Since the use of these metals allows for a constant powerful spark in harsher operating conditions, the thin electrode requires less voltage, thereby reducing the load on the ignition coil and optimizing fuel combustion. It makes sense to put platinum spark plugs in turbo engines, as this metal has a high corrosion resistance and is also resistant to high temperatures. Unlike classic candles, platinum candles should never be cleaned mechanically.

By the frequency of replacing the candles can be placed in this order:

• Copper / nickel spark plugs have a standard service life of up to 30 thousand km., Their cost is consistent with the service life.
• Platinum candles (sputtering on the electrode is meant) are in second place in terms of service life, applicability and price tag. The duration of trouble-free operation of spark ignition is twice as long, that is, about 60 thousand km. In addition, the formation of soot will be significantly less, which has an even more favorable effect on the ignition of the air-fuel mixture.
• Candles made of iridium significantly improve thermal performance. These spark plugs provide an uninterrupted spark at the highest temperatures. The resource of work will be more than 100 thousand km, but the price will be much higher than the first two.

How to choose spark plugs?

First of all, look into the service manual for your car, often, there you can always find information about which brand of candles is installed from the factory. The best choice will be those spark plugs recommended by the automaker, because the factory takes into account the needs of the engine and the technical characteristics of spark plugs. Especially if the car is already with high mileage - investing in it in the form of expensive platinum or iridium candles will at least not justify itself. You also need to take into account what kind of gasoline and how much you drive. It makes no sense to pay money for expensive spark plugs for an engine with a volume of less than 2 liters when the engine does not require prohibitive power.

The main parameters for the selection of spark plugs

1. Parameters and specifications
2. Temperature regime.
3. thermal range.
4. Product resource.

And in order to quickly navigate the candles with the necessary requirements, you need to be able to decipher the markings. But, unlike oil labeling, spark plug labeling does not have a generally accepted standard and, depending on the manufacturer, the alphanumeric designation is interpreted differently. However, on any candles there is necessarily a marking indicating:

• diameter;
• type of candle and electrode;
• heat number;
• type and location of electrodes;
• gap between the center and side electrodes.

As we have already said, when choosing, you need to focus on the actual data of the candles. And in order to understand how all the above characteristics affect, we briefly consider the features of each of these indicators.

side electrodes. Classic old-style candles have one central and one side electrode. The latter is made of steel alloyed with manganese and nickel. However, spark plugs with multiple ground electrodes are becoming increasingly popular. They provide a more powerful and stable spark, which is critical for a candle. In addition, several ground electrodes do not get dirty as quickly, require cleaning less often and last longer.

Candles have similar qualities, the electrodes of which are coated with the following metals - platinum and iridium (the second is a transition metal of the platinum group), or their alloy. Such candles have a resource of up to 60-100 thousand kilometers, and in addition, they need a lower sparking voltage.

Plugs based on platinum and iridium are never mechanically cleaned.

A distinctive feature of plasma-prechamber candles is that the role of the side electrode is played by the body of the candle. Also, such a candle has a greater burning power. And this, in turn, increases engine power and reduces the amount of toxic elements in the exhaust gases of the car.

central electrode. Its tip is made of iron-nickel alloys with the addition of chromium and copper. On more expensive spark plugs, a platinum brazed tip can be applied to the tip, or a thin iridium electrode can be used instead. Since the central electrode is the hottest part of the candle, the car owner periodically needs to perform cleaning. However, in this case, we are only talking about classic old-style candles. If platinum, iridium or yttrium is applied to the electrode, then there is no need for cleaning, since carbon deposits are practically not formed.

* It is recommended to change classic spark plugs every 30 thousand kilometers. As for platinum and iridium candles, they have a higher resource - from 60 to 100 thousand km.

Candle gap - this is the size of the gap between the central and side (s) electrodes. The larger it is, the greater the voltage value is necessary for a spark to appear. Briefly consider the factors that this affects:

1. A large gap causes a large spark, which is more likely to ignite the air-fuel mixture, and also improves engine smoothness.
2. A very large air gap is harder to pierce with a spark. In addition, in the presence of pollution, the electric discharge can find another way for itself - through an insulator or high-voltage wires. This could lead to an emergency.
3. The shape of the central electrode directly affects the strength of the electric field in the candle. The thinner their tips, the greater the tension value. The mentioned platinum and iridium spark plugs have thin electrodes themselves, so they provide a quality spark.

**It should be added that the distance between the electrodes is variable. Firstly, during the operation of the candle, the electrodes naturally burn out, so you need to either adjust the distance or buy new candles. Secondly, if you have installed LPG (gas equipment) on your car, then you must also set the required gap between the electrodes for high-quality combustion of this type of fuel.

Heat number - this is a value that shows the time after which the candle reaches the state of glow ignition. The higher the glow number, the less the candle heats up. On average, candles are conventionally divided into:

• "hot" (having an incandescent number of 11-14);
• "medium" (similarly, 17-19);
• "cold" (from 20 or more);
• "universal" (11 - 20).

 "Hot" plugs are designed for use in low-boost engines. In such units, the self-cleaning process occurs at low temperatures. "Cold" spark plugs are used in highly accelerated engines, that is, where the temperature is reached at maximum engine power.

**It is important to choose spark plugs with a glow rating that is specified in the manual for your car. If you choose a candle with a higher number, that is, install a “colder” candle, then the machine will lose power, since not all fuel will burn, and soot will appear on the electrodes, since the temperature will not be enough to perform the function self-purification. And vice versa, if you install a more “hot” candle, then similarly the car will lose power, but the spark will be very powerful, and the candle will kind of burn itself out. Therefore, always follow the manufacturer's recommendations, and buy a candle with the appropriate glow number!

You can determine the difference between cold and hot candles by marking, or by the shape of the central electrode insulator - the smaller it is, the colder the candle.

Candle sizes. By the size of the candles are divided according to several parameters. In particular, thread length, diameter, thread type, turnkey head size. According to the length of the thread, candles are divided into three main classes:

• short - 12 mm;
• long - 19 mm;
• elongated - 25 mm.

If the engine is small-sized and low-power, then candles with a thread length of up to 12 mm can be installed on it. With regard to thread length, 14 mm is the most common corresponding value in automotive technology.

Always pay attention to the indicated dimensions. If you try to screw in a spark plug with dimensions that do not match the engine of your car, you risk damaging the threads of the plug seat or damaging the valves. In any case, this will lead to costly repairs.

What spark plugs are best for a carbureted engine?

Usually inexpensive candles are placed on them, the electrodes of which are made of nickel or copper. This is due to their low price and the same low requirements that apply to candles. As a rule, the resource of such products is about 30 thousand kilometers.

What spark plugs are best for an injection engine?

There are already other requirements. In this case, you can install both inexpensive nickel candles and more productive platinum or iridium counterparts. Although they will cost more, they have a longer resource, as well as work efficiency. Therefore, you will change the candles much less often, and the fuel will burn out more fully. This will positively affect the engine power, its dynamic characteristics, and reduce fuel consumption.

Also remember that platinum and iridium candles do not need to be cleaned, they have a self-cleaning function. The resource of platinum candles is 50-60 thousand km, and iridium - 60-100 thousand km. Given the fact that recently the competition between manufacturers has been increasing, the price of platinum and iridium candles is constantly decreasing. Therefore, we recommend that you use these products.

What spark plugs are best for gas?

As for machines with installed gas-balloon equipment (HBO), candles with small design features should be installed on them. In particular, due to the fact that the air-fuel mixture formed by the gas is less saturated, a more powerful spark is needed to ignite it. Accordingly, in such engines it is necessary to install candles with a reduced gap between the electrodes (approximately 0,1-0,3 mm, depending on the engine). There are special models for gas installations. However, if the candle can be adjusted by hand, then this can be done with a regular "gasoline" candle, reducing the said gap by approximately 0,1 mm. After that, it can be installed in an engine that runs on gas.