Aftermarket Plugs for Coyote

[Alan_C]

Anyone have experience with aftermarket plugs for the Coyote? Has anyone tried E3 and what was your experience? When I built my MK4, I installed a 4.6L DOHC engine and used the NGK TR55IX Iridium plugs as they were highly recommended at the time. My engine is relatively young, only 2400 miles on a 2017 GT donor motor. I assume that the plugs in the engine are Motorcraft, but are they any good? Is it worth changing the plugs while I have access as my hydroboost will prevent easy access to the two rear plugs on the drivers side. The engine is not in a MK4, rather a 70 Mustang restomod. There is far more Coyote experience here than on the vintage Mustang sites.

[Al_C]

just my 2 cents. I think the plugs that came with the engine are fine. Coyotes are production engines and I can't imagine needing to change them for any reason prior to the point in the Ford maintenance schedule where they should be replaced. Unless you really want to. I suppose that's your choice, but I'm planning on several years' worth of driving on the plugs that got here with the engine... I'm pleased with my engine's performance. In my mind, any "improved" performance would be wasted because I wouldn't be able to keep the car on the road! (maybe that's a driver issue rather than an engine issue, but whatever.)