Every X12 I have/had used standard plugs. I heard that Mugen had started importing them as turbos, but never saw one. You really don't have a problem as they are not interchangeable. If it has a standard head button, a turbo plug won't even thread in. If it has a turbo button, a standard plug will be too small and not grab the threads. If it had a standard plug in it when you got it, then you can only use standard plugs, unless you remove the head and change the button out for a turbo button.