OK, I hit the same ($4.03.9) price up here, haven't seen it lower anywhere else, but I lead a sheltered life, maybe... 29.113 gallons, so I figured my mileage, 384.6 miles since the last fillup, and during that is when I had the 4 bad COPs, coils... 13.21 mpg... Better than I expected considering the bad coils, lots of wide open testing, forced misfires... I figured it would be closer to 10 or so... Next tank, likely a lot better...
Here's what a Ford COP looks like inside, outer heavy primary, inner fine wire secondary... It's cut at a slight angle, so you can see the iron core laminations..

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