Because the federal government doesn't have any guidelines for how booster seats should be designed, the Insurance Institute for Highway Safety is attempting to offer consumers some guidance on what seats to buy. The institute tested 60 different booster seats and found that only 15 of them got top safety ratings.
A number of state laws require booster seats to ensure that adult seat belts fit children properly. If a booster works the way it's supposed to, the shoulder belt fits across the child's shoulder and the lap belt runs flat across the thighs. In a booster seat that produces a bad fit, the shoulder belt slides off the child's shoulder and the lap belt sits on the stomach. This can lead to internal organ injuries.
The Insurance Institute found that the best seats position children properly no matter what type of vehicle they're used in. The following booster seats were called "Best Bets:"
These seats were called "Good Bets:"
Eleven of the tested seats were rated "not recommended." They are:
You can see the full list here, which also includes seats that fall into a "gray area." Remember that any booster seat is better than no booster seat, so if yours is on the "not recommended" list, keep using it until you can get a better one.