Hello

I drove my sisters 2000 VW Passat V6 to work this morning.

I drove about 20 miles in 20 minutes (aver 60mph) all freeway except for a
mile at the beginning and at the end, getting on and off the Freeway.

The outside temp was 56 F.

The water temperature gauge slowly came up; it took about 10 minutes to
reach two lines to the left of center scale (center scale - 190F).  I would
have thought that it would reach the full running temp center scale of 190
by this time.

I drove another 10 minutes and the needle stayed in the same position, two
division marks below (to the left) of center scale.

As I exited the freeway the temp and drove about a mile to my office the
temperature increased about half a division mark, now about 1.5 marks below
center.

I don't know if this is correct behavior as this is my first time driving
the car.  However I am use to a car coming up to temp a bit faster.

My concern is an open thermostat?  The thermostat is a big job on this car,
so I don't want to have it replace unless I am certain.

Any ideas?