Spark Plugs platinum vs iridium

[Loren]

I'll catch flack for this, but it really doesn't matter what plug you use from an economy perspective. Iridium and other unobtanium plugs are used for low maintenance. Under normal usage, they're supposed to last 100k miles.

In extreme usage, they might not last that long. Mine didn't. One of them crapped out on me at the track last year. Replaced them with plain ol' NGK copper plugs. No further issues at the track, and no effect on fuel economy. I'll probably have to replace them every 25-30k miles, no big deal.

I didn't try cleaning mine, but a friend of mine was having severe drivability issues (after several years of track abuse, hard daily driving, and ethanol experiments) on his Nissan, which also uses unobtanium plugs and rather than replacing the plugs, he just gently cleaned them. Worked like a charm for him. The plugs are supposed to be "self-cleaning", but I guess when you ride them hard, they can still get cruddy.

The gap of the iridium plugs does not change significantly, and is not adjustable. No maintenance. Maybe take them out and look at them every now and then, give them a light cleaning (some carb cleaner and a soft non-metallic brush), and put them back in. Other than that... if the car is running normally, let them be.