Ford 2009 F-250 Owner's Manual page 220

Seating and Safety Restraints
When children should use booster seats
Children need to use booster seats from the time they outgrow the
toddler seat until they are big enough for the vehicle seat and
lap/shoulder belt to fit properly. Generally this is when they reach a
height of at least 4 feet 9 inches (1.45 meters) tall (around age eight to
age twelve and between 40 lb (18 kg) and 80 lb (36 kg) or upward to
100 lb (45 kg) if recommended by your child restraint manufacturer).
Many state and provincial laws require that children use approved
booster seats until they reach age eight, a height of 4 feet 9 inches
(1.45 meters) tall, or 80 lb (36 kg).
Booster seats should be used until you can answer YES to ALL of these
questions when seated without a booster seat:
• Can the child sit all the way back
against the vehicle seat back with
knees bent comfortably at the
edge of the seat cushion?
• Can the child sit without
slouching?
• Does the lap belt rest low across
the hips?
• Is the shoulder belt centered on the shoulder and chest?
• Can the child stay seated like this for the whole trip?
220
2009 F-250/350/450/550 (f23)
Owners Guide, 2nd Printing
USA (fus)