Side mirrors
After hitching a trailer to your vehicle, check that the standard side mirrors provide a good rearward field of view without significant blind spots. If significant blind spots occur with the vehicle’s standard side mirrors, use towing mirrors that conform with Federal, state/province and/ or other applicable regulations.
See also:
Warning and indicator lights
...
Gross Vehicle Weight (GVW) and Gross Vehicle Weight
Rating (GVWR)
Gross Vehicle Weight
The Gross Vehicle Weight (GVW) must
never exceed the Gross Vehicle Weight
Rating (GVWR).
Gross Vehicle Weight (GVW) is the
combined total of the weight of the vehicle, ...
Mirrors
Always check that the inside and outside
mirrors are properly adjusted before you
start driving. ...