Does anyone know?

0.055"

Yup thats what i gapped mine at for a few months and plugs still looked excellent. Some people are gaping them higher or lower due to personal preference but i stick to factor, now with my new TR6'* thats another story...

Jag, I'm running my 6'* at .045 so far. Things have been good for over a week. Too short a time period, but right in line with NGK'* advice.

So what does the stock TR55'* gapped to?

I just popped mine in a while ago.. and never got it gapped cause I was in a rush and had to make sure I get to work on time..