When many car owners are doing maintenance for their cars, they often hear the maintenance technician mention the service life of the spark plug and recommend replacing it. However, many car owners are confused about this, not knowing what the spark plug is, why it needs to be replaced, and what impact it will have if it is not replaced. Next, we will answer these questions one by one.

The mystery and function of the "spark plug"

The spark plug, a core component in the gasoline engine (diesel engines use compression ignition technology and do not require spark plugs), plays a vital role in the ignition system of the gasoline engine. It is responsible for introducing high-voltage current into the cylinder, thereby generating electric sparks to ignite the combustible mixture. The structure of the spark plug includes a wire nut, an insulator, a wire screw, a center electrode, a side electrode, and a shell, of which the side electrode is welded to the shell.

The role of the "spark plug"

As an important part of the ignition system, the core function of the spark plug is to introduce the high voltage generated by the ignition coil into the engine cylinder, and ignite the mixture through the electric spark in the electrode gap, thereby ensuring the smooth operation of the engine.

Structural analysis of "spark plugs"

The key structures of spark plugs include: wiring screws, central electrodes, ground electrodes, metal shells, and insulators. Among these parts, the design of the two electrodes is particularly critical, and they directly affect the performance of the spark plug and the working efficiency of the engine.

From the appearance, the top part of the spark plug is called the "terminal screw cap", which is connected to the cylinder wire and is mainly responsible for completing the docking of the cylinder wire. The suction or ejection feeling felt when plugging and unplugging the cylinder wire comes from the careful design here. At the same time, this is also the key part for receiving electrical energy.

Next is the ceramic part below, which is not only insulated and heat-resistant, but also has good thermal conductivity. These characteristics are all due to the excellent performance of ceramic materials. The unique groove-shaped corrugated design on its surface is designed to prevent the generation of arcs, that is, to avoid sparking between the terminal screw cap and the main metal. This is because during the ignition process, continuous high voltage electricity will be generated between the two, and these high voltage electricity may try to flow along the surface of the insulator. In order to prevent this from happening, these layers of gullies are designed.

Closely connected to the ceramic part is the main metal part, which has a hexagonal design (in different sizes) to simplify the removal and installation process of the spark plug. In addition, this part is electroplated to further enhance its high temperature and corrosion resistance. The thread is used to fasten to the cylinder head, and its screw diameter and length vary depending on the engine model.

Finally, there is the electrode part of the spark plug, which is divided into a center electrode and an outer electrode. These two electrodes may be made of different materials. Among them, the precious metal materials we often talk about, such as iridium or platinum, usually refer to the material of the center electrode (some spark plugs may also use the same material for the outer electrode). Compared with ordinary spark plugs made of nickel-manganese alloy, these precious metal spark plugs have stronger ignition ability, but the price is also higher.

In addition, to ensure that the spark plug can perform well at different engine speeds, the copper core is carefully embedded in the center of the internal position, which plays a key role in improving the heat dissipation effect.

Next, let's explore the impact of the spark plug material on its performance. Spark plugs are mainly composed of an iron shell and a central ceramic body, in which the wiring screw and electrode are integrated. Usually, the "gold" mentioned when we choose spark plugs refers to the material of the electrode. It is worth noting that the material of other components except the electrode has a negligible impact on engine performance.

At present, common electrode materials on the market include copper, nickel alloy, platinum and iridium. The conductivity of these metals increases in turn, while the voltage required for ignition decreases accordingly. Therefore, precious metal spark plugs (such as platinum and iridium) perform well in reducing engine load and fuel consumption. At the same time, they are also more durable, but the price is correspondingly higher. For example, the price of a single iridium spark plug generally exceeds 100 yuan.

Spark plug replacement cycle

The replacement cycle of spark plugs is mainly affected by their material. Common spark plug materials on the market include copper core, nickel alloy core, platinum core and iridium core. It is generally recommended to replace copper core spark plugs every 20,000-30,000 kilometers, while the replacement cycle of nickel alloy core spark plugs is slightly longer, about 40,000-60,000 kilometers. In contrast, iridium and platinum core spark plugs have significantly longer service life due to their stable metal properties and strong anti-oxidation ability. Platinum core spark plugs are recommended to be replaced every 80,000 kilometers, while iridium core spark plugs can be extended to every 100,000 kilometers. The following table lists the recommended replacement cycles for spark plugs of different materials in detail.

When should you consider replacing spark plugs? As a key component of a car engine, the performance of spark plugs directly affects the combustion efficiency and power output of the engine. In the following cases, car owners may need to consider replacing spark plugs:

Degraded performance: If your vehicle feels underpowered, accelerates slowly, or has unstable idle speed, this may be caused by aging of the spark plugs.

Increased fuel consumption: As the spark plugs wear, their ignition efficiency will decrease, resulting in incomplete fuel combustion, which in turn increases fuel consumption. If you find that fuel consumption has increased abnormally, this may be a sign that the spark plugs need to be replaced.

Difficult starting: If your vehicle becomes difficult to start, especially during cold starts, this may be due to excessive spark plug electrode gaps or severe carbon deposits.

Engine fault light is on: Hyundai's engine management system is very smart. Once a spark plug-related problem is detected, the engine fault light will usually light up as a warning.

In summary, when the vehicle performance is reduced, fuel consumption increases, starting is difficult, or the engine fault light is on, the owner should consider checking and possibly replacing the spark plug.

During the use of spark plugs, there are two situations that may prompt us to check or replace them. First, when the spark plug's service life reaches its expected life, due to long-term operation in a high temperature and high pressure environment, its ceramic part may become brittle, explode or leak electricity, and the wear of the electrode may also cause the ignition gap to increase, thereby affecting the full combustion of the mixture. Secondly, if the engine intake and exhaust valves, throttle valves and other parts are seriously carbonized, then the spark plugs will inevitably be affected. Since the mixture that is not fully burned after the flameout will adhere to the spark plug, these carbon deposits will gradually form resistance over time, thereby affecting the smoothness of the ignition process, resulting in the appearance of phenomena such as weak refueling and slow response. Therefore, when encountering these situations, the owner should consider checking or replacing the spark plug.

Starting difficulties: If the spark plug is seriously carbonized or worn excessively, it will lead to insufficient ignition energy, which will cause starting difficulties.

Unstable idling speed: When the carbon deposit layer on the spark plug is too thick, the shunt resistance will decrease, which will affect the spark generation of the electrode, resulting in unstable engine operation and reduced power output.

Increased fuel consumption: Spark plug failure will cause abnormal ignition system, which will cause incomplete combustion of the mixture, and the final result is fuel waste and increased fuel consumption.

Excessive exhaust emissions: Due to incomplete combustion of the mixture, some harmful substances are not discharged in a fully burned state, resulting in excessive exhaust emissions.

In addition, different models of engines require spark plugs of different sizes and powers. If improperly installed, it may cause problems such as poor engine operation and increased fuel consumption. In extreme cases, an overly long spark plug may even press against the piston, causing internal engine failure. Therefore, in the absence of professional knowledge, it is recommended to hand over such operations to professional maintenance personnel to avoid unnecessary losses.