Warming up the Engine

["John C." <jvcingwe@infinitecom.com>]

Another question from the ignorance department.  Now that I've moved to
colder climes I notice that almost everyone starts their car and lets it
idle to warm up before they take off.

I had always been told that one should take off immediately and just keep
the revs low until the engine reaches operating temperature, and conversely
that idling is the worst thing for an engine?

Is the warm up just for creature comfort, or is it better for the engine?

BTW, has anyone used Mobil 1 - 0W30 yet.  I saw somehwere that people were
experiencing increased leaks in older engines?

Cheers,

John C.
'83 Ur-Q