ARLINGTON, VA — New ratings from the Insurance Institute for Highway Safety take the guesswork out of selecting boosters most likely to provide good lap and shoulder belt fit in a range of vehicles. The Institute rates 9 belt-positioning boosters BEST BETs, and 6 are GOOD BETs out of 60 models examined in a new round of evaluations. Eleven boosters aren't recommended at all because they do such a poor job of fitting the belt. Fit is important because safety belts are designed with adults in mind, not kids. Boosters elevate children so belts will fit their small frames better to protect them in a crash.

A good booster routes the lap belt flat across a child's upper thighs and positions the shoulder belt at midshoulder. The Institute released its first booster ratings last year, evaluating 41 seats.

"Parents can't tell a good booster from a bad one just by comparing design features and price," says Anne McCartt, Institute senior vice president for research. "What really matters is if the booster you're considering correctly positions the safety belt on your 4-8 year-old in your vehicle. Our ratings make it easier to pick a safer booster for kids who have outgrown child restraints."

The new ratings cover almost all models sold in the United States right now. Manufacturers provided seat model numbers, and the Institute conducted its own check of retail inventories before purchasing seats.

"We're confident we're giving consumers a solid overview of what they'll find when they shop for their children," McCartt says, adding that "parents don't need to dig deep into their pocketbooks to buy a booster with good all-around belt fit." BEST BETs and GOOD BETs include several affordable choices starting at about $20 and ranging up to $250 or more. Big box retailers stock most of them in stores and online, and the rest can be found at specialty baby-gear sellers.

A few just-released boosters didn't come to market in time for this round of evaluations, but the Institute will rate them soon and post the results on this site. The plan is to assess new models throughout the year, much like the Institute evaluates new vehicles for Top Safety Pick awards.

Boosters come in 2 main styles, highback and backless. Some highbacks, called dual-use, convert to backless by removing their backs. These boosters get 2 ratings, one for each mode, because belt fit can differ by mode. Highbacks have built-in guides to route shoulder and lap belts and can offer some head support. Backless models have lap belt guides but may need a plastic clip to properly position shoulder belts in many vehicles.

Ten of the highbacks are combination seats that can be used as forward-facing restraints for toddlers and then as boosters as children grow. In booster mode, parents remove the built-in harness and use vehicle lap/shoulder belts to restrain their children. Seven highbacks are 3-in-1 seats. These are similar to combinations but also can be used rear-facing for infants.

BEST BETs and GOOD BETs: The best-rated boosters are the Combi Dakota backless with clip, Recaro Young Sport highback (combination seat), Recaro Vivo highback, Maxi-Cosi Rodi XR dual-use highback, Evenflo Big Kid Amp backless with clip, Eddie Bauer Auto Booster dual-use highback, Cosco Juvenile Pronto dual-use highback, Britax Frontier highback (combination seat), and Clek Oobr dual-use highback.

"The 9 BEST BETs should provide good lap and shoulder belt fit for typical 4-8 year-olds in almost any car, minivan, or SUV," McCartt says. "A BEST BET that provides good belt fit in Mom's minivan should work equally well in Dad's sedan."

GOOD BETs are the Combi Kobuk dual-use backless with shoulder belt clip, Maxi-Cosi Rodi dual-use highback, Evenflo Symphony 65 3-in-1, Britax Parkway SG dual-use highback, Graco TurboBooster SafeSeat Wander dual-use highback, and Graco TurboBooster SafeSeat Sachi dual-use highback.

"These provide optimal belt fit in almost as many vehicles as the BEST BET models," McCartt points out.

Boosters that aren't recommended: The Institute doesn't recommend the Harmony Secure Comfort Deluxe backless with clip, Combi Kobuk dual-use highback, Evenflo Express highback (combination), Eddie Bauer Deluxe highback (combination), and Evenflo Sightseer highback. Also on the list are 3-in-1s including the Safety 1st Alpha Omega Elite, Alpha Omega Elite, Eddie Bauer Deluxe 3-in-1, Safety 1st All-in-One, Alpha Omega Luxe Echelon, and Alpha Omega.

Half of the boosters that aren't recommended are 3-in-1s that leave the lap belt too high on the abdomen and the shoulder belt too far out on the shoulder. Another seat, the Harmony Secure, has armrests that push the lap belt away from the hips, way out on a child's thighs. Shoulder belt fit is the main problem for the rest — the Combi, 2 Evenflos, and the Eddie Bauer Deluxe.

Dorel Juvenile Group, the largest US children's gear distributor, makes 7 of the boosters that aren't recommended. Dorel seats sell under the names Cosco, Dorel, Eddie Bauer, Maxi-Cosi, and Safety 1st.

"Dorel has 3 BEST BETs and 1 GOOD BET, so this company knows how to make boosters that provide good safety belt fit," McCartt points out. "Dorel tells us it's working on new designs to address issues raised by our evaluations."

Thirty-four seats aren't BEST BETs, GOOD BETs, or on the list of boosters the Institute doesn't recommend. These seats can provide good protection for some kids in some vehicles, but not in as many cases as top-rated boosters. The top 23 in this category provide good lap belt fit across all vehicles. Some parents may find the shoulder belts fit their kids just fine in these boosters. If so, they should provide good protection. Lap belt fit is the problem for the bottom 9 boosters that just miss the not-recommended list. These provide poor lap belt fit most of the time.

How types compare: The Institute doesn't recommend backless over highback boosters and vice versa. Backless ones generally provide better lap belt fit, and highbacks generally do a better job of positioning shoulder belts correctly in all vehicle configurations.

"There's a good mix of highbacks and backless among the boosters we recommend," McCartt points out. "Bigger kids might be more comfortable in backless, but either is fine as long as the vehicle belts fit right."

Highbacks can keep fidgety kids upright, in position for good shoulder belt protection. Shoulder belt guides also deter kids from putting the belt under an arm. "Some companies claim their highbacks offer extra protection in side crashes," McCartt notes. "It makes sense that extra padding and reinforced structures would keep kids safer if the family car is broadsided, but so far research doesn't show a greater benefit for highbacks over backless."

When it comes to the not-recommended boosters, parents may want to reconsider 3-in-1s for their booster-age kids. The selling point for these is they grow with children, so parents don't have to trade up.

"The 3-in-1s should be fine when used as child restraints. The problem is that once the harness is removed for booster use most 3-in-1s lack good belt fit," McCartt explains. "Still, parents using boosters the Institute doesn't recommend shouldn't rush to stop using them in favor of belts alone. Any booster is better than none at all. Take a look at the belt fit, and if it's not doing a good job replace it when you can with one that works better."

New ratings procedure: The Institute can't directly compare the new booster ratings with last year's results to see if particular seats have improved because engineers have modified the test device and protocol. The change makes it easier for manufacturers to reliably reproduce the results. The Institute also evaluated many brand new models.

"Several manufacturers are readying new seats that should do well next time around," McCartt says, "so we're expecting to see fewer not-recommended boosters in the future. Already there's been progress. Manufacturers have discontinued many of the 13 boosters we didn't recommend last year."

How they're evaluated: The Institute assessed the boosters using a specially outfitted crash test dummy representing an average-size 6-year-old child. Engineers measured how 3-point lap and shoulder belts fit the dummy in each of the 60 boosters under 4 conditions spanning the range of safety belt configurations in vehicle models. Each booster gets 4 scores for lap belt fit and 4 for shoulder belt fit. The overall rating for each booster is based on the range of scores for each measurement.