The entirety of the Subaru Legacy vehicle’s operation is jumpstarted by a single perfectly timed spark. The ignition system is considered the heart of the entire Subaru Legacy engine system’s operation because it is where this quintessential spark hails from. At the moment that ignition key, a series of complex processes are commenced inside the engine of the Subaru Legacy. All these processes terminate in one specific event, the firing of the spark plug. The spark plug is mounted atop every cylinder and tasked with sparking the fuel/air mixture, effectively commencing the combustion process inside each cylinder of the Subaru Legacy. Among all the spark plug manufacturers, Bosch is undeniably one of the most reliable spark plug manufacturers around. The Bosch spark plug platinum+4 is more than just your average Bosch spark plug. Built from most superior of all metals, the Bosch spark plug platinum+4 is guaranteed to deliver the optimum engine performance out of your Subaru Legacy every time. The novelty of the Bosch spark plug platinum+4 lies in the basic law that metal is the best conductor of heat. The Bosch spark plug platinum+4 tip is designed to eject the spark to the cylinder and this is done wit the utmost efficiency when the spark plug is hottest, suffice it to say that a defective Bosch spark plug platinum+4 is simply non existent. Grab your Bosch spark plug platinum+4 today and we assure you that it will be shipped within 24 hours of your purchase.