Keeping cold engine under 4000 rpms?

[atcdoug]

I hear everybody say to keep the engine under 4000 rpms until the oil temp gauge reaches 8 o'clock. I understand that you don't want to floor a cold engine but is this really necessary? What happens if you go over the 4000 when the engine is cold? I stay under 4000 until the gauge is at 8 but why?  On a cold day I can be at work before the oil gauge is at 8 o'clock. This is frustrating and about the only time my car sees 5th and 6th gear.

Thanks!

Doug Egan
'97 993 Cab