Saab 9-5 2011 Owner's Manual page 179

178 Driving and operating
The permitted trailer load applies up
to the specified incline and up to an
altitude of 3300 ft above sea level. Air
becomes thinner as altitude increa‐
ses, and thus engine power decrea‐
ses. This reduces climbing ability and
also decreases permissible gross
trailer weight by 10% for every
3300 ft of additional altitude. Gross
trailer weight does not have to be re‐
duced when driving on roads with
slight inclines (less than 8%, e.g.,
highways).
The permissible gross trailer weight
must not be exceeded. This weight is
specified on the identification plate
3 242.
Tongue Weight
The tongue weight is the load exerted
by the trailer on the ball hitch. It can
be varied by changing the weight dis‐
tribution when loading the trailer.
The maximum permissible tongue
weight (187 lbs.) is specified on the
towing equipment identification plate
and in the vehicle documents. Always
aim for the maximum load, especially
in the case of heavy trailers. The
tongue weight should never fall below
55 lbs.