Toyota 2009 Yaris Hatchback Owner's Manual page 171

2-5. Driving information
(6) If your vehicle will be towing a trailer, load from your trailer will be
transferred to your vehicle. Consult this manual to determine how
this reduces the available cargo and luggage load capacity of your
vehicle.
Except Canada:
Toyota does not recommend towing a trailer with your vehicle. Your
vehicle is not designed for trailer towing.
Example on your vehicle
When 2 people with the combined weight of 366 lb. (166 kg) are
riding in your vehicle, which has a total load capacity of 845 lb. (383
kg), the available amount of cargo and luggage load capacity will be
as follows:
845 lb. − 366 lb. = 479 lb. (383 kg − 166 kg = 217 kg)
In this condition, if 3 more passengers with the combined weight of
388 lb. (176 kg) get on, the available cargo and luggage load will be
reduced as follows:
479 lb. − 388 lb. = 91 lb. (217 kg − 176 kg = 41 kg)
As shown in the above example, if the number of occupants
increases, the cargo and luggage load will be reduced by an amount
that equals the increased weight due to the additional occupants. In
other words, if an increase in the number of occupants causes an
excess of the total load capacity (combined weight of occupants plus
cargo and luggage load), you must reduce the cargo and luggage on
your vehicle.
158
Cargo capacity
Total load capacity