2009 Toyota Yaris Owners Manual - Page 566

2-5. Driving information n Trailer tongue load The trailer cargo load should be distributed so that the tongue load is 9 to 11% of the total trailer weight, not exceeding the maximum 70 lb. (32 kg) (Tongue load / Total trailer weight × 100 = 9 to 11%) The total trailer weight and tongue load can be measured with platform scales found at a highway weighing station, building supply company, trucking company, junk yard, etc. Total trailer weight Tongue load 146