How often do you hit the rev limiter?

[Pdwight]

This is a vague question, but I was thinking and wondering how much conservative tolerance do you think is engineered into our engines ?. Do you suppose the theoretical red line is actually say 500 RPM past what is programmed in our ECU and painted on our tachometers ??

Certainly an engine redlined multiple times a day will have a shorter mechanical life than one that is rarely if ever run to redline....but at what RPM does the engine (in good working order)significantly start to self destruct ?