Spark Plugs or Glow Plugs, What is the Difference?

By: Kris LeSueur   |   30 Nov 2020

Spark plugs and glow plugs are the main ignition source in a combustion engine, but what is the main difference? The answer to this is the type of engine they're found in, as spark plugs are only found in gasoline engines while glow plugs are found in diesel ones.

However, the ignition systems on today's cars are highly technological, and they operate at relatively high standards to ensure that your engine complies with the current environmental regulations. So, the question here is, what are glow plugs and spark plugs? How do they work? And why is it important to choose high-quality components?

Glow Plugs

Glow plugs are essential for starting a cold diesel engine quickly. It is a heating element that heats the incoming fuel and air in the diesel engine to encourage efficient fuel combustion for a perfect drive. They have a short warm-up time and can quickly heat up to 1300°C in a matter of seconds. The engine works as promptly as possible. Since they are built for long service life, it enhances the driver's peace of mind while generating clean emissions. It ensures efficiency and performance through the control unit, which translates information from the Engine Control Unit (ECU) into instructions for the glow plugs. Usually, a hard starting engine is a common indicator for damaged glow plugs. The combustion chamber may take time to reach the required temperature for ignition in winters, so if fuel and battery are good, one should check the glow plugs!

Spark Plugs

Contrary to diesel engines, ignition systems on petrol-driven engines are external, meaning that an electrical spark from the spark plug is used to combust the compressed fuel-air mixture. The spark is created from the high voltage produced by the ignition coil and leaps between the electrodes. The released heat increases the temperature, rapidly building up pressure in the cylinder and forcing the piston downwards. The movement is transferred via a connecting rod to the crankshaft that drives the vehicle.

This means that spark plugs have to meet high-performance requirements and deliver a powerful ignition spark between 500 and 3,500 times a minute (in 4-stroke operation). It is regardless of whether the car is driving at high speeds or stuck in traffic. High-tech spark plugs provide low-emission combustion and optimum fuel efficiency, even at -20°C, without misfiring, destroying the catalytic converter by allowing unburnt fuel to enter it.

As the temperature begins to drop, your car engine is likely to take more time to start, and you'll see hard starting or engine misfiring along with a decreased fuel efficiency. To avoid the harsh climate and extra workload, get your spark plugs checked and see if they need a replacement. Once you get this fixed, you will see your engine perform better and have a good time on the road!

Please find out more about your car engine health by visiting us at LeSueur Car Company.

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