Just replaced my spark plugs after 137k miles on my 05' WRX. Unfortunately I didn't plan ahead and had to settle for Autolite Platinums. They had NGK copper, but I'd rather have platinum.
Either way I am planning on switching them out after 5-10K I would like to try and replace them with something nice. Iridium seems to be the step up from plat.
There is double platinum, iridium, and whatever Pulstars are. Let me know what you think. I guess buying pre-gapped would be a good idea too.
On small side note, when I was replacing my plugs I checked the gap of my stock plugs and it was .040 for every single one. Is this just because the tip had worn down that much or did the factory not gap the plugs? I gapped my replacement plugs and all has been fine, has anyone else discovered this?