I am going to replace my spark plugs in my 2007 Ranger so I pulled one out to see what number it had on it. The number was Motorcraft AGSF24N and I don't know if it was original or not as the owners manual says see dealer for size. M/C AGSF24N crosses to Motorcraft SP412 but in reading several posts on some other websites they talk about other numbers. I want to replace the old plugs with either single or double Platinum style Motorcraft plugs and when I looked at the Motorcraft SP412 they said the core was copper. Any comments?

 

Only use regular copper or nickle(no coating) or double coating, never single coating as its a waste of money, in any engine with a Coil Pack

Double will last longer but either will provide the same spark

For 2007 4.0l use Motorcraft SP500(has double coating) or SP412(has no coating) as replacement closest to OEM

But Autolite or NGK are also fine to use, double coating or no coating, must have the 0.054" gap


The coating thing
Coil packs use Waste Spark, this means one coil in the pack sparks TWO spark plugs at the same time, wired in series
So one spark plug sparks from center to tip(regular spark), the other spark plug sparks from tip to center(reverse spark)
A coating is usually put on the tip to reduce wear, in a V6 engine with single coating spark plugs that would mean 3 spark plugs would wear out the same as no coating spark plugs, so a waste of money
Because Ford actually uses 100,000+ spark plugs a year they use 2 different spark plugs with coil packs, in this case 3 with coated tip and 3 with coated center, as its cheaper than 6 double coating
But for single user 6 double are not that big of an expense, vs finding 3 of each type

Waste spark was the very first spark system used in 4-stroke gasoline engines back in 1890's so its well tested, lol, any single cylinder 4-stroke engine uses Waste spark, just FYI