Spark Plugs For Trimmer How to Choose

Useful tips for choosing spark plugs for a car: what types exist, from what material I make them, and so on.

Spark Plugs For Trimmer How to Choose

The content of the article:

  • Choose spark plugs
  • Candle Features
  • What does a candle look like
  • Work temperature
  • Video

Have you ever had to choose spark plugs? Do you know that they are different: multi-electrode, iridium, platinum? Are you sure that the low price provides the necessary technical characteristics of your car? If not. We are ready to fill this gap in your knowledge.

What are the criteria for choosing spark plugs?

Before choosing spark plugs, it is worth deciding on what they generally are. The design of the part is quite simple and consists of three elements:

  • A metal housing having an external threaded portion;
  • Internal conductive element (electrode);
  • Ceramic insulator insert.

The principle of operation of the spark plug is simple and effective, its task is to create the spark necessary to ignite the fuel mixture. The principle of formation of an electric circuit closed by a spark plug is based on the connection of the metal housing of the spark plug with the engine through it. With a car body and, accordingly, with a negative battery terminal. This allows for the supply of "mass". DC to the side electrode of the ignition device. Alternating current is supplied through the high-voltage wires connected in the upper part of the spark plug and is caused by the pulse supplied when the ignition system is activated. The resulting spark ignites the mixture in the fuel chamber of the engine, starting it.

Design Features of the spark plug

The classic design of the candle suggests the presence of one central and one side electrode. Modern devices. More durable due to the use of composite materials. Bimetallic alloys to improve the characteristics of metals, or through the introduction of alternative technological solutions. So, cut in the body of the electrode allows you to double the resource. But, traditional single-electrode candles continue to be in demand, the price of which is estimated at the minimum values.

Even more modern spark plugs for a car have a multi-electrode design with two, three, four side electrodes located around the body like flower petals. These types provide a reduction in fuel consumption, improved fuel combustion processes, give a slight increase in power and stable operation of the motor. It is worth noting that the life of such candles is twice the life of conventional single-electrode options.

Another important criterion in choosing spark plugs is the material used in the manufacture of the central electrode. In budget models, copper, nickel, zinc, iron are used. In expensive modern spark plugs, performance is enhanced by the use of central rare-earth metal electrodes. Iridium, platinum, silver alloys. Initially, these types were created for racing cars, today they are used everywhere. At the same time, the difference in the cost of candles from ordinary and rare metals more than covers the resource intensity of platinum and iridium. Up to 100,000 km versus 30,000 km for classic copper or zinc.

External parameters of the spark plug

The geometric parameters of spark plugs for cars in recent years have undergone significant changes. So, modern. Much thinner and longer than their counterparts, released a couple of decades ago. Changes in geometry. It is a tribute to the constructive changes of modern engines, leaving less and less space for candles. Today, the most popular dimensions of the threaded element of parts are indicators of 19 mm, 12.7 mm, 14 mm, sometimes there are options with a thread length of 10? 12 mm.

The dimensions of the candle body have also undergone changes. Modern models, for the most part, have a turnkey diameter of 16 mm, while more recently, the vast majority of spark plugs for cars were screwed in with a 21 mm key.

Glow plug number

The glowing number of the spark plug determines its operating temperature. The lower it is, the slower it will heat up and will be able to withstand higher temperature conditions. The indicators of the glow number from 14 to 20 are considered normal, but the entire series assumes a range from 8 to 24 points. It is important to consider the recommendations of the automaker: the wrong choice of the glow number of the spark plug can lead to premature engine wear due to exceeding the permissible operating temperatures.

Do not save in trifles, and you will not encounter serious problems during the operation of the car. And choose spark plugs based on real characteristics, and not guided by questions of price or degree of promotion of the manufacturer’s brand.

Video with expert advice on how to choose the right spark plugs for a car:

An article about spark plugs for a car engine – varieties, selection criteria. At the end of the article – an interesting video on how to clean candles from soot.

The content of the article:

  • Spark plugs – varieties and features
  • Classification by electrode material
  • Rating of the best spark plugs
  • What candles are better to put for the engine on gas
  • Video on how to clean spark plugs from soot

The operation of the engine largely depends on the spark plugs, and the performance of the latter depends on the manufacturing company and manufacturing technology. The rating of spark plugs is most often led by recognized market leaders such as Bosch, Denso, Beru and some others. These companies supply their products to automobile concerns, therefore they strictly monitor the quality and adherence to technology.

Spark plugs – varieties and features

Video: Spark Plugs For Trimmer How to Choose

The main value when choosing is the material from which the electrodes are made, as well as their number.

By the number of spark-forming spark plugs are divided into two- and multi-electrode (plus plasma-prechamber, which is a novelty in the market).

Two electrode

They have a main (central) and side electrodes. Candles of this type are a classic variety. When starting between the electrodes, a spark is formed that ignites the fuel mixture.


In addition to the central one, they have two or more lateral sparking devices. The principle of operation is the same, but the design allows to stabilize the formation of sparks and the operation of the motor system.

Plasma prechamber

Such candles appeared on the auto parts market in about 2000 and are still provoking discussions. Neither experts, nor ordinary motorists have come to a consensus about what this new product is – either the next step towards improving efficiency, or a futile attempt to improve.

Prechamber candles differ from traditional ones in that the side of the electrode is played by the body of the product equipped with a special heat-resistant nozzle. It is with its help that a spark forms.

Classification by electrode material

Copper / Nickel

The main characteristics of spark plugs are quality and budget. Of course, in terms of operating parameters, products are far from those that will be discussed below, but for their price segment they have decent readings. On average, a copper-electrode spark plug is enough for 20-30 thousand kilometers, after which replacement is required.

Platinum (sometimes made from other precious metals)

The electrodes of the products have platinum deposition, due to which their service life is increased and quality is improved. Such a candle is designed for mileage of 50 thousand km.


The resource is up to 100 thousand km, and quality indicators are many times better than the previous options. But the cost of the product is corresponding.

Rating of the best spark plugs

Market leaders have been determined for a long time. The results of tests, consumer polls, expert opinions sometimes differ, but the same brands almost always occupy the top positions in the ratings.

1. Bosch

The company’s products can be characterized in two words – German quality. Not for nothing that the brand confidently leads in all the top selection of spark plugs. Bosch products are equipped with cars such as Fiat, Audi, Toyota, Mitsubishi and others. The company provides a considerable choice, but some models are especially popular.

Which spark plugs are better and what are their features?

Model Bosch WR7DP

Number of electrodes: 2.
Coating Material: Platinum.

  • Stable operation even with a low battery;
  • High environmental performance
  • Long service life (about 60 thousand kilometers);
  • Good performance when working with HBO;
  • Universality (the model is compatible with most cars, including domestic production).


  • High price.

Model Bosch FR7DC

Number of electrodes: more than 2.
Coating Material: Yttrium.

  • The resource is higher than other budget options;
  • Low cost;
  • Increased resistance to spark damage.


  • Sensitivity to low quality fuel.

2. Denso

Another undisputed market leader, focusing on the latest technology.

Denso PK20PR — P8 Model

Number of electrodes: 2.
Coating Material: Platinum.

  • Low cost in comparison with other platinum products;
  • Long service life;
  • Universality (candles are suitable for most cars, including models that have been discontinued);
  • At high speeds, an effective self-cleaning process takes place;
  • Structural elements have high quality characteristics.


  • Intensive carbon coating when idling;
  • Not the best option for installation on a car with HBO.

Model Denso K20TXR

Number of electrodes: more than 2.
Coating Material: Nickel.

  • Stable functioning;
  • Resistance to spark damage;
  • Perfect value for money;
  • Increased resistance to oxidation.


  • Not the best option for installation on a gas-powered car.

3. NGK

Worldwide sales exceed 450 million and continue to grow. The company supplies its products to automobile plants such as Ferrari, Volvo, BMW, Volkswagen, etc.


Number of electrodes: 2.
Coating Material: Iridium.

  • Long service life (up to 50 thousand kilometers or more);
  • Stable operation even with a low battery;
  • Increased resistance of the central electrode insulator to damage.


  • High price;
  • Hypersensitivity to fuel quality.


Number of electrodes: more than 2.
Coating Material: Nickel.

  • Resistance to corrosion;
  • Adequate cost;
  • Stable operation at both high and low speeds;
  • Profitability;
  • A good percentage of increase in power compared to peers;
  • Resistance to low quality fuel.


  • Low rate of environmental friendliness.

To the question "What spark plugs are best for the engine?" it is safe to answer that NGK. Their feature is nickel plating and an affordable price, taking into account quality. Nickel has excellent protective properties, so the elements of candles are minimally susceptible to various corrosion and damage.

4. Brisk

The brand has several highly specialized lines. For example, the Classic line is designed to be combined with carburetor engines, and Silver is ideally combined with gas-powered cars.

Model Brisk Premium LOR15LGS

Number of electrodes: 5.

  • Long service life (from 50 thousand km of run);
  • Profitability;
  • Stable operation in any conditions thanks to four side electrodes;
  • High rate of power;
  • Resistance to low quality fuel.


  • High cost (this is one of the most expensive spark plugs).

5. Champion

It complements such car brands as Suzuki, Jaguar, Alfa Romeo.

Model Champion RN9YCC4

Number of electrodes: 2.
The electrodes have a copper core.

  • More stable operation in comparison with analogues;
  • Good indicator of profitability when working at high speeds,
  • High level of environmental friendliness.


  • Inflated cost;
  • Unstable operation at low speeds;
  • Compatibility with a limited number of cars.

6. Beru

The company’s products are distinguished by quality and good performance, although in some points it loses to the “meters”.

Model Beru Ultra — X79

Number of electrodes: 4.

  • The optimum ratio of price and quality;
  • High level of environmental friendliness;
  • Stable operation in cars both on gasoline fuel and gas;
  • High rate of environmental friendliness;
  • Steady spark even with a strong tan.


  • Low percentage of power increase with the throttle open.

What spark plugs are best for a gas engine

The peculiarity of the gas is that its combustion temperature is slightly higher. This provokes an intense formation of carbon and the appearance of oxides on the electrodes. Therefore, for cars on gas, it is recommended to install products with platinum or iridium spark formers.

When used on machines with HBO, good results showed:

  • Denso Iridium IW20;
  • NGK LPG Laser LineN2;
  • Bosch Platinum WR7DP.


The most important thing when choosing spark plugs for an engine is not to purchase a fake. Handicraft enterprises market a huge amount of counterfeit of the lowest quality on the market. Therefore, when buying candles, you should pay attention to the reputation of the outlet, as well as check the part and packaging for belonging to the original.

Video on how to clean spark plugs from soot: