Researching iridium plugs

[Bigvinnie]

Alright I need people to answer weither or not if iridium plugs truely last 80,000miles before there next change.I have used iridiums before and I still do for my 2005 nissan murano, the murano doesn't even have 30,000 miles on it yet. I use platinums on the KA24de 240sx. I've been told by Nissan that the Denso iridiums last to about 80,000 miles before there next tune up. How much truth is there to it, and if I decided to use NGK's would they outperfom and last just as long as the denso's.I've had a couple of friends that own KA's and KA-t's give me some mixed answers some telling me no matter what they should be changed at 30,000, and some telling me they don't know how long they last, but defenitely more than copper or platinum plugs.The opinion is so mixed that I would like to see where others stand on the issue..

[Fenris]

As to how long they last, not so sure, but I yanked out a set of 4-prong bosch platinums in favor of NGK iridiums and lost alot of the roughness and improved my gas mileage by 1 mpg so i count it as a victory. I'd recomend em.

[Bigvinnie]

I use the bosch platinum 4 already. I do notice increased gas mileage on my KA24de, but then again my VQ35de is a v6 that gets just as good gas mileage with the iridiums (around 27 to 30MPG with a K&N filter). Compression ratio has alot to do with that since it increases engine VE, but I defenitely know that the iridums sparks better on leaner mixtures.I have been looking to lean out my engine a bit more on the KA24de and with the higher heat tolerances I am affraid that I will need to switch to iridiums. I also have my timing advanced for a total of 23 BTDC. I don't notice any detonation or knock and ping with the platinums they do work quite well. I defenitely wont ever go back to copper, I would sometimes have to replace them early. It would just be nice to get a set of plugs that I wouldn't need to change out at every 30,000mile tune up. Platinum 4's run me about $24 for all 4. Iridiums would cost arounf $44 with half as many tuneups.

[Fenris]

$4 Dollar Savings Woot!

Also, Post #100!!!

Again Woot

[Bigvinnie]

iridium conducts electricity better than platinum. That means iridiums spark better. I'm getting the NGK iridiums..

Iridium

Iridium is a precious metal that is 6 times harder and 8 times stronger than platinum, it has a 1,200(=F) higher melting point than platinum and conducts electricity better. This makes it possible to create the finest wire center electrode ever. Prior till now, platinum had been favored for long life or performance spark plugs due to its high melting point, also the technology did not exist to machine and bond iridium on a spark plug electrode(at least in a cost effective manner). Iridium industrial spark plugs have been around for years, but still sells for over a hundred dollars per plug. Just now is the technology available to effectively use iridium in a spark plug for automotive applications. The strength, hardness and high melting point of iridium allows NGK to manufacture their iridium ultra-fine wire center electrode to 0.7mm. One of the finest firing points in the industry! (Thus far there has been no problems reported regarding use of iridium plugs with nitrous oxide.)