Spark Plugs – Everything You Need to Know

When working with Spark Plugs, tiny metal devices that create the spark to ignite the air‑fuel mixture inside each cylinder. Also known as ignition plugs, they form the heart of the Ignition System, the collection of coils, wires and control modules that deliver high‑voltage electricity to start combustion and have a direct impact on Engine Performance, how smoothly the engine runs, how much power it makes and how efficient the fuel burn is. Because they sit at the junction of electricity and fuel, any deviation in their condition can ripple through the whole powertrain.

Key Topics Covered

The most common trouble sign is a misfire, which shows up as a rough idle, loss of power or a sudden drop in fuel economy. These symptoms are usually tied to an incorrect Spark Plug Gap, the distance between the centre and ground electrode that determines spark strength. A gap that's too wide or too narrow weakens the spark, causing incomplete combustion and higher emissions. Alongside gap, proper torque is vital; over‑tightening can crack the ceramic insulator, while under‑tightening leads to heat‑related failure. Checking the gap with a feel‑er gauge and tightening to the manufacturer‑specified torque (often around 15‑20 Nm) keeps the ignition reliable and protects the catalytic converter.

Understanding these details lets you spot a bad plug before it leaves you stranded. You’ll learn how to test a plug with a simple visual inspection, when to replace them based on mileage (usually 30,000‑60,000 miles for copper, longer for iridium), and why using the right heat range matters for different engine loads. Below, you’ll find practical articles that walk you through symptoms, DIY testing steps, cost considerations, and expert advice on choosing the best replacement for your car or boat. Armed with this knowledge, you can keep the engine humming, improve fuel economy and avoid costly repairs – all without needing a garage appointment.