A good fit is easier than ever to find when shopping for a booster seat. This year a record 31 seats have been designated BEST BETs by the Institute. They include an inflatable booster, a NASCAR-themed booster, boosters with cup holders and pivoting armrests, and plain vanilla boosters. Prices range from under $15 to several hundred dollars.
All of them, however, have one thing in common: They correctly position a vehicle safety belt on a typical 4 to 8 year-old in almost any car, minivan, or SUV. No matter what extras a seat may offer, the ability to provide proper fit is the essential feature that a booster must have.
In addition to the BEST BETs, another 5 seats are GOOD BETs, meaning they provide acceptable belt fit in most vehicles. Six boosters are not recommended because they don't provide proper belt fit, and consumers are advised to avoid them.
In all, the Institute evaluated 62 booster models. Twenty-one of them show up twice in the lists. These are dual-use seats, which can work as highback or backless boosters. In the ratings, each dual-use model is considered to be 2 separate boosters for a total of 83 seats evaluated, 11 more than last year.
The biggest group of boosters falls into a middle category, designated "check fit." These 41 seats may provide good fit for some children in some vehicles, but not as many as GOOD BETs or BEST BETs. Parents are advised to make sure the lap belt lies flat across a child's upper thighs and the shoulder belt crosses snugly over the middle of the shoulder. If not, a different seat is needed.
The focus of the Institute's ratings is belt fit, not crash performance, and no crash tests are conducted as part of the evaluation. To assess belt fit, engineers use a test dummy representing an average-size 6 year-old. They measure how lap and shoulder belts fit the dummy in each booster under 4 conditions representing the range of belt configurations in real-world vehicles.
Improvements and innovations
Boosters have improved a lot in recent years. In 2008, the first year the Institute published its evaluations, there were 10 BEST BETs. That fell to 9 in 2009 but soared to 21 last year after manufacturers began using Institute test protocols as they designed and updated seats (see Status Report special issue: booster seats, Oct. 1, 2008, "Which booster is best for me?" Dec. 22, 2009, and "More boosters earn top ratings for belt fit, but most still don't," Sept. 8, 2010).
"Just 4 years into our ratings program, parents have a wide variety of top-rated seats to choose from," says Anne McCartt, the Institute's senior vice president for research. "Still, boosters that don't consistently provide good belt fit outnumber the ones that do, so consumers need to keep paying attention to this issue."
One thing consumers need to be aware of is that most dual-use boosters have different ratings for each mode. For example, 14 dual-use boosters are BEST BETs or GOOD BETs in highback mode but are designated check fit in backless mode. For one seat, the Evenflo Big Kid Sport, the opposite is true: It's a BEST BET in backless mode and a check fit in highback mode.
The Harmony Dreamtime remains the only dual-use booster that's a BEST BET in both modes, while the Combi Kobuk Air Thru is a GOOD BET in both modes.
A notable newcomer to the BEST BET list is the inflatable BubbleBum, marketed for vacations and car pools. It inflates by blowing into a valve at the seat's back (see sidebar).
Several of the highbacks on the BEST BET list claim to provide enhanced protection in a side crash through the use of deeper side walls, special padding, or other technology. Safety 1st, for example, touts its "Air Protect" system on the Boost Air Protect and S1 Rümi Air seats. The system's cushions release air upon impact to minimize forces on a child's head.
Such enhancements, however, don't affect the Institute's ratings, which are based solely on belt fit. It's not known to what extent side-protection systems on boosters are effective in real-world crashes.
Among booster manufacturers, Harmony Juvenile Products continues to be a standout. All 5 of the seats the Canadian company currently makes, counting the Dreamtime in both modes, are BEST BETs. The company is discontinuing the dual-use Baby Armor, which was a BEST BET in highback mode but not recommended in backless mode.
For boosters, it's all about fit.
Boosters elevate children and position safety belts so the belts will fit them better. The lap belt should lie flat and on top of a child's upper thighs, not higher up on the abdomen. The shoulder belt should fit across the middle of a child's shoulder. If it falls off the shoulder or rests on the neck, a child might move the belt behind the back or under an arm.
Small change, big difference
Diono, which recently changed its name from Sunshine Kids, bumped an existing seat, the Monterey, from check fit to BEST BET by changing the shoulder belt guide. The new ranking applies when the dual-use seat is used in highback mode. The booster remains a check fit in backless mode. Consumers should look for Montereys manufactured after July 2011 to ensure they are getting the newer version.
Meanwhile, the Evenflo Symphony 65, which has been a GOOD BET since 2009, now has a sister seat, the Symphony 65 e3. It has a slightly different shoulder belt guide, and that makes enough of a difference to make it a BEST BET.
"Booster manufacturers often use similar names for different seats or, in the case of the redesigned Monterey, even the same names," McCartt says. "It's important for consumers to look at model numbers and manufacture dates when consulting our ratings."
Telling different seats apart can be even harder with boosters made by Graco. The company has multiple versions of some boosters, which for the most part differ only in the amount of padding. That small difference can sometimes affect belt fit.
"With Graco seats, different fabric patterns sometimes are the only clue beyond the model numbers that you're dealing with two different seats," McCartt says.
The Institute's current year booster ratings include model numbers of the exact seats tested.