Child car seats.(Buyers Guide)(Evaluation)

A child car seat--any car seat--can greatly reduce the odds that your child will be injured in a crash. This is especially true now, with the increased use of tethers, straps that secure safety seats to anchors bolted into cars. Still, largely because of the way they're used, as many as eight out of ten safety seats may not adequately protect the children riding in them, according to the National Highway Traffic Safety Administration (NHTSA). Protection can be compromised in several ways.

* Parents use the wrong seat for their child's age, weight, and height, or for their car.

* A seat isn't installed in the car correctly.

* A child isn't properly secured in a seat.

The design of a seat can also cause problems. Our tests showed, for example, that some seats used both for toddlers and older children have shoulder-belt guides that may allow slack in the belts, meaning that a child may not be sufficiently protected in a crash. (See "Boosters Are a Must" on page 28.)

In this report, we'll help you determine which type of car seat is right for your child at various ages, weights, and heights. We evaluated 33 safety seats, priced from $30 to $200, for ease of installation and use and for crash protection, based on crash tests simulating a frontal collision at 30 miles per hour. (See "The Tests Behind the Ratings" on page 31 for details.) We tested four types of seats that cover children from newborn through grade school: infant seats, convertible seats for infants and toddlers, toddler/ booster seats for toddlers and older children, and booster seats for older children. (See photographs and details below.)

Our tests showed that most of the infant, convertible, and booster seats should do a fine job of protecting your child. But several of the toddler/booster seats require special care in booster mode, and a few should be avoided in the booster mode because of design problems. (Model-specific advice is in the Ratings on page 30.)