What do you guys think about this? I've heard a few stories of cracked ceramic headers. But is it really worth doing? does it keep engine temp down that much?

 

I've seen first hand a set of headers (on a v8) ruined because of header wrap. header wrap is not really for a street application - but it does look damn cool!

Heat (from wrap) is worse for your headers then it is good for performance. Thats my opinion.