Ok where do I start.....
Lets start by clearing up resistance...
Every metal has a specific resistance to it. It's resistance is measured mostly with a very little specific
amount of electricity passing through it. While it is true copper has less resistance than platinum at very low currents.
It is alao true when you up the voltage and current to all know metals it will increase in it's resistance properties in respect to the available energy as expressed as amps and the available push of that energy expressed as voltage, passing through the metal.
Now this is the important part here.... When a "given" (IE: same) amount of increased
voltage and amps do all metals increase in resistance at the same amount/curve? I think your getting the catch here now. Copper will increase in resistance (expressed in heat) at a much greater rate than platinum will.
So when you are pushing 8 to 10 amps at 40,000 volts through a chunk of copper it has a huge resistance properties to it over platinum of the same size. This is because platinum doesn't heat up as much due to lower resistance at higher voltages and amps, and it is of a denser material than copper is. This denser material allows higher electron flow with less resistance at higher voltages. If my chemistry memory serves me right over 20 years ago hehe.
Ok so now your wondering what is the advantage of platinum plugs over copper plugs and spark energy generated? Since platinum plugs have a lower resistance to large amounts of electricity than copper does this means there is a hotter spark at the actual time the energy jumps the gap between the center electrode and the ground strap. More resistance would stand to reason the energy is spread out over a longer time/dwell than say a plug with less resistance. This means the spark energy is more intense and of a shorter duration in a plug with less resistance.
Now as to why platinum plugs last longer than copper ones. Copper transfers some of it's own electrons with the spark energy when a spark plug fires. This transfer of it's own electrons causes a molecular errosion of the copper element. Platinum molecues are much much more tighter in the electron eliptical patern around the neucleus of the platinum atom. This allows more platinum molecues in the same size, as a piece of copper. Hence platinum is a denser metal than copper is. The protons in a platinum atom are very strong and they pull the elctrons in tighter orbit around it's nuecleus which consists of equal number of protons and nuetrons. Protons are positively charged and electrons are negatively charged and nuetrons have no charge. Nuetrons work like the glue to hold the protons in a atom. The speed of the electrons circling the protons/nucleus of a platinum atom are much higher. But the pull of the protons on the electron (Opposites attract) are incredibly higher than say copper. This means it is more resistant to electron transfer!
Why are platinum plugs more resistant to fouling? They produce a hotter spark which cleans the plugs and the platinum itself is denser so the carbon atoms have a less porous suface to stick too. I am sure there may be other reasons too but no need to spend a day here listing and posting them here.
I know this is really deep and I am sorry to go into such detail but there are a lot of miconceptions here and it was necessary to help understand a bit of atoms and how they work.
Keep this in mind... why do we use copper as heating elements? It is because when we increase the voltage and amperage it heats up really good! This heat is great for toasters, base board heaters, etc..! This heat is called electrical resistance! Plain and simple. There are a lot cheaper metals out there than copper, but we use copper because it heats up so well.
platinum plugs also tend to come apart and do some serious damage under high heat instead of just fouling or melting like copper or silver plugs.
That is very true. Platinum is much more brittle than copper. So if your detonating then I wouldn't recommend these plugs. But if your detonating... your engine may not be long for this world anyways. This "comming apart" as N1tr0 says was a real problem with the original bosch plugs. I don't believe it will be an issue with the newer plugs though as they have 75% to 100% more platinum in them. That means the core should be 1 3/4 times to 2 times thicker than the original plugs! As for serious damage? The strand of platinum in the original plugs was so small I doubt very seriously any significant damage was ever done to any engine. I suppose it may have been possible but I never heard of anything. The platinum if it ever did get loose in the engine would probably just get expelled out the exhaust valve. Remember this is a tiny very small piece of platinum.... there is no way it would bridge the gap between the cylinder head and the piston and poke a hole in the piston. The only thing I can think of is it may get caught between the valve and the seat but carbon does that all the time. Hmm I don't think there really is any way whatsoever that any damage could be done by a small chunk of platinum from a bosch original spark plug in a street engine. None of you are running a nitro mix in your commuter cars are you? Please feel free to post back with any proof as I am real curious to see if there is even one issue ever of this happening! No hoaxes please.
'performance' plugs may seem like the simplest upgrade for beginners, but they're not worth the money, they're placebos, junk, and likely not as good as the oem part.
Are you flaming me? Calling me a beginner? Because spark plugs are easy to change/upgrade. Doesn't necessary mean you should call people beginners. Most people will see through petty comments such as this. It only weakens what you say from this point on. I spoke in facts and data. Not name calling and flaming. Think about it. By the way where is your facts and data on comments such as that? I have explained how they last longer, stay cleaner, produce a spark that is exposed to the air/fuel mix better, burns the fuel more completely, and produces a hotter spark to boot. Hmmm seems to me the stock ones are not better over time are they. Show me your proof!
I've tried them, they haven't made any difference.
What enviroment are we talking here? Were your old plugs worn? Did most all the fuel burn with your old plugs installed? If there was nothing wrong with the old plugs you may not notice any difference just driving around normally. The difference would show up on a gas analyzer though. It may also show up on a dyno test. 1 hp or less increase would be hard to test for and I don't think your looking for tons of hp output from changing from a good plug to a good plug. The things you will appreciate is over time mostly. Longer plug life, less emmissions should be the benifits you may not notice untill time passes. Compare your emissions test from your old plugs when they were new and your new bosch plugs and then you have some data to work with. Just be aware that you will have more milage on your vehicle when you put in the bosch plugs. But I think you will still see your emissions drop in comparison. This drop equates to more complete burn of the fuel and more power and more milage that you may not notice otherwise.
Guys remember this isn't nitrous oxide or a super charger here. These are merely spark plugs. It is not a new engine in a spark plug here.
If the plugs fail you or you don't like them... here is a link to get a refund on them. They are guarenteed for the life of the recommended milage in your owners manual. Bosch Peformance Guarentee form http://www.boschusa.com/AutoParts/SparkPlugs/Platinum/