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Spark Plugs 101

Spark Plugs 101

If you value your vehicle's performance, you would be interested in knowing how an engine receives its’ energetic ignition that sets the pace for efficient and effective implementation. When it comes to combustion engines, spark plugs play a vital role in an engine's ignition process. Spark plugs channel electrical energy from the ignition coil and ignite the air-fuel mixture within the combustion chambers, assisting in the vehicle's mechanical operation. Spark plugs also serve as an essential diagnostic tool to evaluate the operating conditions in your engine. The quality of the transmitting function of spark plugs has a significant effect on your vehicle's smooth-running and engine performance. In this article, we will discuss the intricate workings of a spark plug, along with the different kinds of spark plugs that NGK has to offer.

What Do Spark Plugs Consist Of?

Centre Electrode

For a standard spark plug, a centre electrode consists of nickel alloys. Generated spark energy takes a leap from the end of this electrode to the ground electrode.

Ground Electrode

The ground electrode is also mostly made up of nickel alloys. It serves as the opposite electrical pole for the central electrode.


A gasket is a ring that prevents any form of gas leakage from the combustion chamber, which may want to arise due to extremely high pressures. Serving as a pressure regulator, the gasket allows optimal heat conduction to the cylinder head while ensuring a balance between the spark plug housing and the expansion of the cylindrical head.

Metal shell

The metal shell is a crucial part of the spark plug because it transfers heat from the combustion process away from the insulator and the cylinder's head.


An insulator consists of ceramic and aids in transferring heat away from the firing end of the cylinder. Insulators provide an optimal electrical insulation level by preventing high electrical voltages from escaping externally through the engine block or other components.

Inner seals

The seals consist of a talcum ring embedded within two additional stainless-steel sealing rings. It provides an airtight connection between the metal housing and the insulator. When the spark plug is manufactured, the talcum ring is tightly compacted by the steel rings to ensure a perfect seal.

Current Leakage Barriers

The current leakage barriers reside on the outside of the insulator, thereby increasing the area of course for electrical energy traveling to the metal. This process prevents leakage of electrical current onto the body of the vehicle.

Connection terminal

The connection terminal is about a 4mm thread connection point. A high-tension ignition lead or direct ignition coil is present. This connection terminal allows high voltage from high tension sources to transmit to the spark plug's firing end. Some NGK spark plugs have a removable terminal nut or both nut and thread terminal types.

Spark Plug Heat Range

The heat ranges of spark plugs highlight the rate at which a spark plug can transfer heat from the firing tip to the cylinder head.
A ‘cold plug’ transfers heat at a higher rate, allowing the firing tip to cool faster. In contrast, a ‘hot plug’ has a much slower heat elimination rate, keeping the firing tip hot. 

The way a spark plug is designed determines its’ ability to eliminate heat from the combustion chamber. You can either alter the length of the core nose or change the electrodes alloy composition.

Most manufactures depict heat ranges with a number which represents the spark plug being either hot or cold. Cold spark plugs perform well with engines that run at high rpm, whereas hot spark plugs are typically for engines that run at low rpm.

NGK Spark Plugs (2-11)

As one of the leading manufacturers of spark plugs globally since the 1930s, NGK spark plugs are effective, efficient, and long-lasting. NGK's commitment to manufacturing the best quality spark plugs has made them a clear brand choice. There is a vast array of NGK spark plugs to choose from, depending on what suits your needs.

Standard NGK Spark Plugs

These spark plugs have a core made up of copper that allows for more sparks and a long insulator nose to reduce the level of fouling. The triple gasket seal feature of these plugs help to eliminate leakage of gas from combustion chambers. Standard NGK spark plugs have a zinc coating to prevent corrosion with insulators which have corrugated ribs to minimize flashover.

Fun fact: These plugs work efficiently on various motorbikes such as Honda Recon 250s, Suzukis, and a host of others. They are quite efficient and keep the engine temperature low as 24-degree Fahrenheit or as high as 100-degree Fahrenheit. 

NGK V power (Copper) Spark Plugs

The NGK V power spark plugs are factory-approved and are an excellent upgrade from the standard spark plugs. The particular V-Groove center electrode and concave ground electrode feature of NGK V power spark plugs increase ignition capacity by generating spark between the center electrode's edges and the ground electrode. The V-Groove center electrodes also provide a greater area for flame expansion.

V-Power Spark Plugs have a resistor that reduces Radio Frequency Interference (RFI) or ‘electrical noise’ that may cause interference with the operations of radios, electronic components, fuel injections systems, depth finders, and other sensitive electronic equipment.

The presence of trivalent metal plating equips the plug with superior anti-corrosion and anti-freezing properties. Also, the plugs have maximized fuel economy with reduced emissions. They are highly durable against mechanical and chemical wear.

NGK V-Power Racing Series (Copper)

These series of spark plugs are for racing engines. The high level of performance often subjects the engines to severe conditions, hence the need for a spark plug with advanced technologies and upgraded features.

The electrode materials are precious metals such as gold or platinum for more outstanding durability and lower voltage consumption. The center and ground electrodes are also configured in such a way to improve the spark and ignition level. The insulator noses also improve the throttle response tremendously. The projected tip of the racing spark plugs gives a noticeable difference to standard V-power spark plugs at requisition time.
The NGK V Power Racing Series is available here.


Iridium IX Spark Plugs

NGK 2668 Iridium IX Spark Plugs

NGK Iridium IX spark plugs meet the demand of highest-level performance engines. It provides the best of ignition, maximum throttle response, and state of the art anti-fouling feature. The fine-wire iridium center electrode offers high durability with consistent and stable sparking ability. The ground electrode special taper cut-shape also increases the area for flame expansion.

Iridium alloy has an extremely high melting point, making this spark plug more suitable for high-performance engines. The trivalent metal plating also adds to the plug for superior anti-corrosion and anti-freezing properties.

NGK Laser Iridium Spark Plugs

NGK Laser Iridium spark plugs last longer than the Iridium IX spark plugs, with a range of 80 to 100 thousand miles compared to 40 to 50 thousand miles of the Iridium IX spark plugs. NGK Laser Iridium spark plugs provide increased ignition and long service life due to the platinum disc welded to the ground electrode's backside.

The smallest tip diameter available on iridium surfaces allows for a slower wear rate. This construction provides stable idle, superior anti-fouling properties, improved fuel efficiency, and lower emissions.

NGK G-Power Spark Plugs

The NGK G-Power spark plugs are made up of a single platinum tip, 98% pure copper core, and a 0.6 mm fine wire center electrode for more focused sparks and increased ignition. The trapezoidal ground electrode shape reduces quenching, and the alumina silicate ceramic allows for more robust insulation. The presence of the insulator nose configuration improves throttle response. It prevents fouling with corrugated ribs on the insulator to prevent flashover.

NGK wire sets

These spark plugs meet the strict factory requirements using varied pitch wire winding, which allows for increased resistance to radio frequency interference. These sets also give optimal quality, superior firing, high durability, conductivity, and noise suppression. They are well known for their consistent performance.

The wires are also fitted with optimistic locking and are resistant to corrosion. The stainless-steel terminal ends fit tightly and securely to the spark plugs allowing for quick and vibration-free ignition. The wires are color-coded and numbered for easy identification and recognition.

Final Thoughts

NGK spark plugs are quite popular and renowned for their effectiveness and durability. They have brought out the best technological advancements and innovations, making the most cutting edge technology available to high-level performance engines. After analyzing the purpose of which spark plugs serve along with the different kinds of NGK spark plugs available, it is evident that choosing NGK spark plugs is the wise choice due to their innovation and cutting-edge performance.

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