Chevrolet 2009 Impala Owner's Manual page 240

Steps for Determining Correct Load Limit
Locate the statement "The combined weight
1.
of occupants and cargo should never exceed
XXX kg or XXX lbs" on your vehicle's
placard.
Determine the combined weight of the driver
2.
and passengers that will be riding in your
vehicle.
Subtract the combined weight of the driver
3.
and passengers from XXX kg or XXX lbs.
The resulting figure equals the available
4.
amount of cargo and luggage load capacity.
For example, if the "XXX" amount equals
1400 lbs and there will be five 150 lb
passengers in your vehicle, the amount of
available cargo and luggage load capacity is
650 lbs (1400 − 750 (5 x 150) = 650 lbs).
4-22
Determine the combined weight of luggage
5.
and cargo being loaded on the vehicle. That
weight may not safely exceed the available
cargo and luggage load capacity calculated in
Step 4.
If your vehicle will be towing a trailer, the load
6.
from your trailer will be transferred to your
vehicle. Consult this manual to determine how
this reduces the available cargo and luggage
load capacity for your vehicle.
If your vehicle can tow a trailer, see Towing a
Trailer on page 4-28 for important information on
towing a trailer, towing safety rules, and
trailering tips.