Brisk Silver Racing RR14S Spark Plugs 4 Pack - Ford Focus ST 2013-2018, Focus RS, 2015+ Mustang 2.3L - 1 Step Colder
Brisk Silver Racing RR14YS Spark Plugs 4 Pack - Ford Focus ST 2013-2018, 2.0L Zetec, 2015 Mustang 2.3L - 1 Step Colder
Denso (5340) ITV22 Iridium Power Spark Plug 1 step colder - Pack of 4
Brisk Silver Racing RR12S Spark Plugs 4 Pack - Ford Focus ST 2013-2018, 2015+ Mustang 2.3L, Focus RS - 2 Step Colder
Motorcraft SP-550 CYFS-12Y-PCT Iridium Spark Plugs 4 Pack - FORD FOCUS ST/RS, Mustang (Replaces SP-537)
