Ford Motorcraft Ecoboost Spark Plugs SP-580 (Set of 6) CYFS-12-YT4
For the 2011-2016 Ecoboost 3.5L, there are two main plugs we recommend, stock OEM SP-534 aka Motorcraft CYFS-12Y-T3 and NGK 6509. Some applications may require 1 step colder, but for most all we recommend these two plugs. ***The SP-580, aka CYFS-12-YT4, superceeds the SP-534.***
These spark plugs should be gapped at .030 or .032. The SP580 has the benefit of being very close to .032 out of the box. We still recommend verifying gap before installing.
This listing is for a set of 6 SP 580 spark plugs, gapped at .032 (verification required). These are OEM Ford Motorcraft plugs. We recommend changing the plugs at every other oil change or around 10-15k miles.
Common symptoms that show spark plugs should be replaced are a rough idle, mis-fires, P0300, P0301, P0302, P0303, P0304, P0305, P0306, cutting out when accelerating, rev limiter feeling.