Let's hear some opinions on spark plug brands. Application is a factory stock 2000 Formula. I usually stick with the stock AC's' but I've heard the NKG 55's mentioned and what about that new E-3 plug? Is there something better out there than the AC's as far as quality, durability, longest lasting, and better spark efficiency? Thank's Dave.

I've never seen proof one way or another that one plug is better than another. I've heard people bash one brand and like another. Truth is,all a spark plug does is spark. I'd like to hear of real differences if any.

I gotta agree with Tyler. Have never seen a real difference between spark plugs--nothing that can be proved. Usually, the engine screws up some how and takes out the plugs before they ever get to their rated max mileage anyway. Iridium plugs are the latest, but doubt they will last any longer than the platinums and iridium is even more expensive. Ran some regular tipped Bosch plugs for awhile in my '94, didn't notice any difference from the platinum, except that the regular tips really do wear out faster...they were still good for about 30,000 miles, though. I wouldn't recommend any one spark plug brand over another. Remember, the plugs are pre-gapped, and if you gotta gap one, it's better to try and take it back. If the center or side electrode is scratched while gapping, it will be eaten up really fast.

Appreciate the info guys, and I did know about the touch-me-not electrodes on the high mileage plugs Chuck. I just use my well trained eyeball for a feeler gauge! I guess what I was looking for here is more of a poll, which plugs are different people using?

watch i'll add a couple of things. there is some article my bro came across that it's not so much the brand of spark plug that matters but more the position it is screwed on and well of course the gapping. what i am referring to is the relative direction of the electrode to the fuel injector. i mean it kinda makes sense, fuel will ignite quicker if it can get to the spark faster. an article my bro read about said they simultaneously ran two identical cars side by side and the one that had the spark plug node pointing towards the fuel injector ran slighter higher in drive no throttle than the other car. my thoughts, its not a significant change and the time to adjust each spark plug no thanks but thats an idea.

also depends where you live. here in el paso, tx actually in juarez i once filled my tank with Magna Premium (octane is about close to 90) from Pemex, gas stations in mexico while running regular autolite coppers and the bird ran like on cruise control even up at 40-45 an not even tapping the gas pedal...it was kinda freaky at first but true story, something must have been wrong and i made sure cruise control was not on.

ive never had problems with Bosch or Autolites when they are gapped properly but you also need to consider what you do to keep them healthy. proper fuel octane and clean injectors as well as a healthy opti and wires even fuel filter replacement. but that of course should be taken into consideration when making these kinds of polls. ive always wanted to try out the E-3, the design is different and kinda goes back to the initial idea in the first paragraph i'll try to find that article and post it up. but each e-3 plug is like $8 so x 8=$64+tax dang but forget about AC Delco ever since my bad experience with their warranty and quality of batteries no more. just don't get Champion or those crazy 3-4 tipped electrode plugs, 1 is enough. number one thing too is how you drive....high speed glazing