Platinum vs Iridium plugs whats the difference?

[SteveU]

I have been using Bosch regular platinum plugs and am wondering how they compare to NGK iridiums. Specifically, does one outlast the other by a large margin & give superior performance & fuel economy? Vehicles I work on are 95 geo metro, 96 Jeep grand cherokee, 93 toyota corolla, 95 dodge neon (not all mine). Are the iridium plugs worth the extra money given that none of the vehicles I work on are hard to get to or are they mainly for the vehicles that are so hard that you only change them out once in the life of the vehicle? How many miles can either one go before performance & mileage is degraded?
Thanks,
Steve

 

[Asteroid]

Platnium good for 80000 Iridium good for 13000mls. No real fuel saving advantage,Stick with Platnium, Save your self a few $$ use NGK. Alls well that ends well.....Yes some Manufacturers use em for hard to get at plugs but others use em for long life...

 

[T-Keith]

Almost all other platinum/iridium plugs will be better then Bosch. Iridium is pretty much replacing platinum, it has most of the same benefits, although usually better.


-T

 

[Matt_S]

Iridium has two advantages over platinum. It conducts electricity better and it's tougher, so it will wear better. In reality, this means that they can make an iridium tip smaller than a platinum one. The smaller tip tends to perform better. The design life of iridiums is typically 100k miles, which is similar to platinums, but people tend to have better luck with iridiums actually performing well for that entire lifespan. Many platinums tend to be worn out by about 60k miles.

So, basically, they are better plugs, but they tend to be expensive. It pays to shop around, though.

Check out this link:

http://www.ngk.com/sparkplug411.asp?kw=Iridium&mfid=1

 

[Chevynut67]

I'm lookig to get a set of Iridium plugs as well. I've found that NGKs are about $5 cheaper than Densos and they also make the plugs for GM.