the besy plug is what works for you. i have used most every plug on the market adn have found that for me autolite and bosch seem to work best. i like the platinum plugs as well as they seem to fire even when heavily fouled, especially the bosch platinums. some plugs i would stay away from are the splitfire's, far too expensive, a/c fire ring plugs, not reliable as far as i have found, and champion, dont last anywhere near as long as the autolite's. prices for platinum plugs run about $1.50 to $2.50 per plugs. splitfire's start at $3.50 per plug, and their platinum plugs run as high as $6.50 per plug. way too high in my opinion.
I like Autolites, AC's and NGK's, which I used in bikes for years with zero problems, despite my best efforts to screw them up. I would NEVER pay the extra money for Platinum's again, since I tried them a few years ago in my bike and repeatedly fouled them, even though the standard plug of the same brand and one-third the price was stone reliable. Wouldn't put Champions in a lawnmower.
I would to say NGK in general. It seems that different motors favor different brands. For Ford, autolite and motorcraft is fine. I don't feel the difference with the NGKs, so why pay the higher cost($3~4).
Back to the Orig Post, NGK seems to have the better engineering behind it. They make all kind of crazy looking spark plugs. Beside that, if the top fuel drags uses NGK, it looks good to me.
NGK Copper plugs are by far the best out there. Stay away from Platinum plugs. Platinum is a horrible conductor of electricity. It resists corrosion very well, that's why manufacturers use them so they can say "100,000 miles between tune-ups". Good ol' NGKs are 2 bux a plug max and they kick ass. If they can handle 30psi in a DSM motor, they sure as hell can do well in a N/A V8.
I just took my 99 Exploder in to get the intake manifold gaskets replaced.
They saw I had put in Bosch Platinums. They said the 4.0 SOHC shouldn't have those and recommended the stock Motorcraft plugs.
I don't get it.
USE THE FREAKING $.88 SPARK PLUGS THAT CAME IN THE ENGINE!!!!!!
People get themselves in trouble when they start using platinum, quad diode fancy schmancy stuff, a correctly gapped plug in an appropriate heat range will give you the best performance, skip the other junk.
I put NGK's in both of my 2000s and they worked very well. I'm sure the motorcraft parts will do fine with an older V8, but I really liked the copper NGKs, as someone else stated they do have a credible track record.
Put what came in your vehicle...
GMs (especially anything after '96): ONly AC Delco... GM actually has calibrated their computers based on those plugs, throw in anything else and it WILL run like crap. Had a recent customer throw in some 12.99 iridium densos into his '01 slow-maro... immediately through a doubled 'random-multiple cylinder misfire' code. Ran like crap. ~I didn't sell them too him, a recent hire we nicknamed 'slow kid' did, do the math ~
Ford: I prefer motorcraft, usually seems a bit better that Autolite... I know my gf's old escort with the 8-plug 4cy liked motorcraft better than autolite. And that was one finiky engine. And most OE plugs I come across now are Motorcraft.
European: Bosch Platinum... it's a german plug and seems to run the best in these applications.
Import: Denso or NGK, I believe NGK has the edge in quality.
Dodge: Champion believe it or not, as far as I remember these are the OE plugs.
Multi-electrodes.... throw them out, they are a waste. Splitfires can do what the adds say, but you have to index them in your combustion chamber, and even then only marginally better. If your car didn't come with platinum plugs, don't run platinum- it's only advantage is it burns cleaner (if you check the book, in the same plug type, normally the bosch super will burn hotter than the platinum).