Optional in your case. I run colder plugs now but i didn't at first. I only decided too when i switched to a stratified tune that included the log review. With a log review it's like a baby custom tune where they go over your engines vitals and tweak a few things to extract a bit more power. Colder plugs reduce the chance of detonation and gave them a bit more head room to work with. I could've done it without the colder plugs but i'm a fanatic. Generally, colder plugs are a must have when you're going for aggressive tunes, big turbo, etc... Cobb tunes are conservative and run just fine with oem plugs. I would even argue it would be a waste to go colder on a Cobb OTS (off the shelf) tune. And the extra cranks on start up probably aren't doing any favors to my starter
