Iridium Spark Plug Set

The Ford Performance M-12405-35T spark plugs are designed as a one-step colder option for enhanced performance in tuned Ford EcoBoost engines. This set includes six iridium-tipped spark plugs with a projected insulator, a 14mm thread size, and a tapered seat design. It is important to note that these plugs are not pre-gapped and require careful adjustment to a gap of .026-.028 inches before installation. These spark plugs are specifically engineered for compatibility with the following Ford vehicles and engines: 2017-2026 3.5L Raptor/F150, 2018-2020 2.7L F150, and 2021-2026 3.5L engines. While they fit the 2021-2026 3.5L engines, they utilize a tapered design rather than an OEM washer. Installation requires precise torqueing to 11.1 ft-lbs. For optimal performance and longevity, especially in tuned applications, it is recommended to change these spark plugs every 15,000-20,000 miles. Due to the specific nature of this performance upgrade, returns are not accepted on this item.