Motorcraft Spark Plug Set - SP-550 Focus ST/RS

The EcoBoost engine operates under extreme conditions including high cylinder pressures. The spark plugs are subject to rapid wear rates, even at standard performance levels. Engines running higher boost points or increased levels of tuning can experience reduced spark plug life resulting in lower engine performance, misfires, and rough idle. Increased wear is typically seen in the form of an increased spark plug gap and degradation of the electrode.For optimum power and performance, we use genuine Ford Iridium spark plugs and replace them every 10,000 - 12,000 miles. Genuine Ford Motorcraft Iridium Pre-gapped Applications: 2016-2018 Focus RS 2013-2018 Focus ST