My wife's 1995 855 GLT has a pretty harsh ride. I am surprised other
Volvo owners say they have smooth rides since a harsh ride is a common
complaint seen here on this board. Are you speaking with 850 GLT or
850 turbo owners? As I recall, the 850's shocks and springs on the
GLT are the same as the turbo model (but the turbo gets 16 inch lower
profile tires and has an optional sport suspension).

In general, 850s have a somewhat harsh ride. Ours kind of "crashes"
through harsh bumps (always has).

The low pressure turbo engine really has nothing to do with it -- Volvo
just seems to like stiff suspensions. Probably to improve waht they call
"dynamic safety" in that the car can be kept under control better in
an emergency.

Volvo did soften the ride a bit for the 70 Series -- my 1998 S70 T5
has a softer ride then the 855 GLT. In my opinion, that was one
of the big improvments the 70 series offered. It is not a big difference
but enough that you notice it if you were to drive an 850 and then
a 70.

Others have experimented with shocks and springs to soften the 850s ride.
I recall several posts here on that topic. You might use the search tool
to search on "harsh ride 850" or similar to find the older posts.