Originally Posted By: SirTanon
When I changed the plugs in my Fusion right around 215,000 miles, I put Autolite Double Platinums in it.. unfortunately, I went the wrong route. Not necessarily because they are bad plugs, but because they're not fine-wire electrodes. They'be been in the car now just over 10,000 miles, and while they work, I don't think they're working as efficiently as a comparable set of fine-wire plugs.
The plugs I pulled out of the car were the original factory FoMoCo fine-wire Iridium plugs, and my MPG and power have both dropped somewhat since the swap. It MAY just be that the coils (also factory originals) didn't react well to being separated from the plugs after all that time, and are now just giving out after being disturbed.
I've already ordered some NGKs, and when my new coils get here, I'll most likely be swapping the plugs out along with them. I may swap the coils first to see if things improve, and if my mileage and power go back to what they were before. If they do, the Autolites stay in, but I'm thinking that I'll probably end up just putting the NGK plugs in, in the end.
[censored], I've even considered putting the original, 215,000 mile plugs back in to see what happens.
Just wonder, was there some aversion or circumstance of not wanting to replace with Motorcraft OEM plugs? When I have always dealt with Fords, using OEM Motorcraft replacements was dollars and sense ahead with that brand.