The ignition system of your vehicle depends heavily on the efficient function of the BMW spark plug wires to operate at its best. The BMW spark plug wires are the connection that transmits the high voltage spark to the spark plugs, enabling them to ignite the fuel in the engine cylinders to start the combustion process. The coil transmits its high voltage burst to the distributor, where it is sent through the distributor rotor to a series of contacts, one for each engine cylinder. The BMW spark plug wires then carry the voltage through their heavily insulated wires to the spark plug positioned at each engine cylinder, where the spark plug uses it to ignite the fuel. The BMW spark plug wires can deteriorate over time, their protective insulation becoming cracked from the heat of the engine or contamination from vehicle fluids. If the insulated jacket of the BMW spark plug wires becomes damaged the transmission of spark to the engine can be interrupted causing performance problems, such as engine misfire. Moisture can contaminate the BMW spark plugs if their protective covering has been breached, causing the vehicle to run roughly during rain or very humid weather. The BMW spark plug wires are equipped with a rubber boot on each wire end, fitting unto the spark plug and forming the connection that transmits the voltage from the wire to the spark plug. This boot can become loosened or damaged over time, failing to transmit power efficiently. We carry a selection of quality BMW spark plug replacements in our online catalog, all at great low prices. Our secure site makes ordering safe and easy or our toll-free phone line can take your BMW spark plug wires order just as efficiently.