operating temperature?

[Jeremiah Curry]

Howdy all,
 
The other day a friend was riding in our 99 Passat V6 and asked why it never
reached operating temperature.  The center of the temp guage is labeled 190
and it never got close.  That made me wonder and I noticed that my 1991 200
20v never gets to the middle of it's temp guage either.  Should it? (it is
about 20 degrees outside, but they have both been on fairly long drives, 1
hour or more)  I am wondering if either or both of them have bad
thermostats, they both blow warm from the heater, but not really hot.
 
thanks,
Jeremiah