Greetings,

Trailer brakes - while always a good idea - are just part of the equation.
There are a LOT of variables that go into safe towing.  Here are just a few.
Please note, many are generalizations and different folks out there will
have different opinions and experiences but I've found that these all hold
true for me:

1.  The tow rating on any vehicle can vary widely depending on how it's
reported by the manufacturer.  Sometimes, a vehicle with a 3000# tow rating
will not be able to pull a 3000# trailer safely if the tow vehicle is
loaded.  Many times the rating is reported with the vehicle empty, a half
tank of fuel and only the driver.  Every pound you add to the vehicle
decreases the weight available for the trailer.  A good rule of thumb (while
still occasionally debated) is not to have your trailer's gross weight
exceed 75% of your vehicle's maximum towing capacity.
2.  Rear wheel drive is generally preferred over front wheel drive, mainly
for the size and capacity of the transmission, the increased amount of
circulating tranny fluid and the ability for it to cool itself.  That
doesn't mean that a FWD vehicle won't tow a camper, just that if you do you
should be extra careful and consider such options as an external tranny
cooler.
3.  A tow vehicle with a longer wheel base is preferred over one with a
shorter wheelbase.  This helps to stabilize the ride and prevent "the tail
wagging the dog" syndrome.
4.  In that vein, a heavier tow vehicle is preferred over a lighter one,
especially as the overall weight of the trailer increases.
5.  On a tow vehicle, light truck tires are preferred over passenger car
tires.  This generally has to do with the overall load capacity of the tire
and the stiffness of the sidewall (a stiffer sidewall helps prevent
wallowing).  The greater the load on the tire, the more heat is produced as
you drive.  Also remember to increase your air pressure as your load
increases - see the info on the tire sidewall for the max pressure and
capacity.
6.  A solid rear axle (like that in a pick-up truck) is preferred over an
independent rear suspension (like that in many cars and smaller SUV's).
This has to do with the overall load handling capability of the vehicle as
well as reducing wallowing.
7.  The reported weight of many campers is what we call "dry" weight.  Dry
weight seldom if ever includes added options (like A/C, propane tanks,
water, a refrigerator, etc.) and definitely does NOT include the weight of
your gear, food, clothing, bicycles, etc. that you loaded into the camper
yourself.  The only true way to know what your camper weighs is to take it
to a public scale (truck stop, city dump, etc.) and have it weighed.
8.  Make sure your camper is loaded "60/40".  That means 60% of the overall
weight of the camper should be in front of the axle and 40% behind.  The
tonge load (weight of the camper that rests on the hitch ball on your tow
vehicle) should be around 15% of the overall trailer weight.  The trailer
should also be as level as possible.  A trailer loaded rear-heavy,
rear-down, and/or with a low tonge weight is easily subject to sway - and
that can be very dangerous at any speed.

Good luck and I hope this helps - Jonathan

It appears that the last year Volvo made an 850 was in 1997...so
everything on the car has 10 years of wear...

First, NEVER tow anything more than about 2000 pounds without trailer
brakes.  In most states it is illegal to do so.  In fact, what little I
could find bout Volvo towing stated that "brakes are required for towing
anything over 1540 pounds".  That means installing the wiring for a
brake controller in your car, and a decent brake controller.

Second, most tow ratings assume that nothing but the driver is in the
towing car (your Volvo).  You must decrease the towing capacity by any
other people/gear you put in your car.

Third, a 16 foot viking is likely the "2308" which lists a hitch weight
of 220 pounds, an axle weight of 1528 pounds, and a cargo capacity of
972 pounds, meaning a fully loaded 2308 could weigh around 2700 pounds.
 (Look for the model number and the weights on a silver label on the
outside of the camper somewhere). The "axle weight" is often listed
WITHOUT the weight of the AC, full propane tank, battery, awning, and
sometimes the fridge!  That means that the 'cargo capacity' of your
camper is probably several hundred pounds less than the listed 972
pounds.  Gear you put in the camper adds up very quickly.  Water, for
example, is 8.3 pounds per gallon.

Fourth, there is a common 'rule' that safe towing involves towing at
only 75% of listed capacity.  For 3300 pounds, that means 2475 pounds is
the 'safe' limit.  Remember that you have to subtract the weight of
passengers and gear in the car from that!

Fifth, if the car was not factory equipped for towing, you will need to
install a transmission cooler ( I don't THINK it already comes with one,
but I am not sure).

SO, if you drove carefully, with a class III hitch, a transmission
cooler, brakes on the camper with a decent brake controller in the car,
did not plan to go up and down very many hills, did not plan to take
long trips, traveled without too many passengers and with only moderate
camping "stuff" taken along, the Volvo 850 PROBABLY could safely tow a
16 foot Viking.

HTH

In my opinion ... which is worth nothing  ... Volvo is EXTREMELY
conservative in their rating.  I tow my Coleman pup 1550 lbs with my 87 240
then load me, wife, kid, lots of guns and shooting supplies and about 1000
rounds of lead ammo plus a weeks worth of boondocking needs  ... you can't
even tell it is pulling the thing BUT  ... the brakes are a weak link  ...
regular Volvo brakes are nothing to right home about  ... since 91 Volvos
have had 4 wheel discs on most models which makes it a lot easier  .... my
91 244 brakes a lot better but the wsedan can't hold all the stuff.  I dod
recommend a tranny cooler  ... just because it is the right thing for
insurance  ... not because I think it is a problem  ... the 87 has almost
250,000 miles on it and a lot of them towning us around to shooting events
... go for it but careful on the brakes.