Did you know that the least expensive operating parts in your engine are also some of the most important? Spark plugs and ignition leads are critical components within your vehicle’s ignition system. Every petrol engine needs them in order to operate. They maintain your vehicle’s functionality and performance. Today’s ignition leads are made of carbon filaments that are surrounded by insulating shields so they can withstand the high heat and energy under the bonnet. Nevertheless, each time a current goes through the wire, the carbon breaks down a little, causing the wires to slowly degrade. Eventually this leads to decreased power, acceleration and fuel mileage, as well as misfires.