When to change spark plugs on 06 V8?

[knightsfs4]

I heard iridium is best, but I don't know when it'll be time to change them. What do you guys think?

Jack

 

[Eastcoastrunner]

I heard iridium is best, but I don't know when it'll be time to change them. What do you guys think?

Jack

100k mark usually. Also, make sure you get the right ones. Amazon sells them at a good price i heard

 

[SMEE]

Iridium is best. Maintenance book says 120,000 miles, but folks on this forum say 90-100,000 miles. Personally, I'm planning on doing it at 90,000. Can't hurt, right?