Stuck engine oil drain plug

[TM]

While this is not going to help Eyvind's problem right now, but
what I've resorted to using when the plug is stuck is a 17mm
impact socket and a breaker bar. Even under the car, the breaker
bar allows me to get enough leverage to break the bolt loose.

Using a 6-point socket with the radiused corners that engage on
the flats rather than the corners of the bolt is most important-
I learned that lesson after (fortunately not) nearly stripping
the bolt w/ a Craftsman 12-point socket.

Also, it is important that you have that copper gasket between the
oil pan and the plug.

Personally, I'd rather use the conventional plug w/ a 17mm head
rather than one that takes an Allen because I feel that the conventional
plug with the proper socket will be easier to remove and less prone
to stripping.

Worst case, if it's really stuck, I'd try grinding a slot into the
head of the bolt and using a big screwdriver, or drilling the bolt.

You can do the above at your own risk.

Taka