I'm wondering if these are better than the ac delco plug that came in our cars?
I have 01 z28, M6.
I have about 33000 miles, so I thought it might be about time to replace them?
What do you guys think about them, excpet that they are $12 a piece?

 

hehe, fact is your spark plugs will perform just fine until they reach about 80,000 miles (with about the same output as new). The denso iridium plugs are just a bunch of hype They sell'em because iridium sounds cool.

http://www.iridiumpower.com/

I wouldn't waste that much money on spark plugs.

 

I work for a parts store, which means I can get them for almost the same price as the regular plugs. I've seen an advertisement in CHP where it makes about 6hp over stock plugs on a 4.6l mustang.

 

All hype

 

for what it's worth, here's my iridium experience:

i put NGK iridiums in my bike (99 GSX-R750). they're supposed to last longer than standard plugs. well, after a couple hundred miles, i started blowing the 10A ignition fuse that runs current to the coils/spark plugs. i called NGK and asked a tech rep if the iridiums should pull any more current than standard plugs. he said no. i blew 4 fuses over approx 300 miles, so i put the standard plugs back in. no problems. decided to test my theory, so i put the iridiums back in, and immediately started blowing fuses again. currently running standard plugs in the bike and have had no fuse problems.

for this reason, i will never put iridiums in my car.

 

Iridium is less conductive than platinum and they're both les conductive than copper. That means it takes more juice to spark them. Iridium and plat will hold up longer than copper.

I wouldn't run any plug up to 80K miles. I've changed platinum plugs that have been in that long and there is a definate increase in power after the change.

You will see No performance increase in running designer plugs unless your plugs are totally trash. That goes for splitfire, +4, rapid fire, etc. Then you'd see the same benefit from stock replacements. The only time the fancy plugs will help is if your ignition has a defeciency.

CHP had an add that showed power increases? Well, I've seen adds for the tornado in mags that claim power increases too. Don't believe ads. Besides, they're always "up to" claims. That means 0 hp to whatever they claim.

Besides, ricer's swear by iridiums. That should tell you something. lol

 

Yea, I was wondering if platinum/iridium conducted electricity better or not, thanx for clearing that up.
What spark plugs do most of you guys put in after you take out the stock ones. Do you just go with the ac delcos again.
A colder plug wouldn't be needed until about 400 hp or so, am I right?
I would like to thank everybody for their input.

 

Just some other plats of the same heat range. I choose plats because they last longer, and cost under $2/plug. With the difficulty of getting to a certain plug that shall remain namelss, I'll stick with plat. Thats what the ignition system is set up for anyway.