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Re: Car Seat
For some child car seats, slim safety margins
The American Academy of Pediatrics advises parents to keep children in rear-facing car seats as long as possible--ideally up to the car seat’s weight limit--because it’s generally safer.
But when we crash-tested rear-facing car seats at manufacturers’ claimed weight limits, several had significant problems.
The attachment broke on the Combi Avatar convertible seat, sending it flying off the test rig, at a crash speed lower than that which the government requires car seats to withstand. We rate the Combi Avatar as Not Acceptable, and urge the manufacturer to fix the problem.
The Evenflo PortAbout 5 infant seat flew off its base at a crash speed just above the federal standard, a margin of safety that is too small, in our judgment. We have rated it poor for crash protection.
Two other seats had problems that were less serious. The Britax Marathon convertible seat and the Combi Tyro infant seat tilted back on impact more than the federal standard allows. But those car seats didn’t break loose in our tests.
With all four models, problems occurred only when the seats were in their rear-facing position and attached with Lower Anchors and Tethers for Children, or LATCH, a universal connection system for child car seats and passenger vehicles in which connectors on the car seat attach to metal anchors in the car.
By contrast, when we connected the child car seats with car safety belts, all performed fine. So if you already own one of those car seats, you don’t need to throw it out. Just install it with the car’s own safety belt, not with the LATCH connection. Other details of our tests include the following:
• There appear to be problems in the way some car seats or their LATCH straps are designed. On multiple units, the LATCH strap broke on the Combi Avatar and the seat disconnected from the base on the Evenflo PortAbout 5. We noted a similar though less severe problem with the PortAbout 5 when we tested that model two years ago.
• A number of seats in the rear-facing position did a poor to fair job restraining the head of our test dummy from rebounding into the vehicle’s back seat after a crash.
We did find excellent choices among the dozens of models we tested. Most infant and convertible seats received excellent or very good scores in our crash tests; all booster seats performed well. We also found that some $70 seats performed as well as those costing $200.
Moreover, designs in general appear to be getting better. More boosters have shoulder-belt guides to allow proper belt retraction in a crash. Attachment tethers are more secure. Manufacturers have adopted safer, five-point harness systems. And many LATCH connections make car seats simpler to install.
Testing to the limits
Consumer Reports is the only organization in the U.S. to rate car seats for crash protection. All seats are tested with LATCH straps at least once. If we discover a problem, we buy more units and test the seats further at two labs. For this report, all seats were tested in simulated head-on crashes at or very near the federal safety standard of 30 mph. (The test is such that crash speeds vary slightly.) We used test dummies at the manufacturer’s maximum claimed weight. That’s up to 22 pounds for rear-facing infant seats and up to 35 pounds for rear-facing convertible seats.
Manufacturers certify that their car seats meet those conditions. After the seats are on the market, the National Highway Traffic Safety Administration tests them, but not at their limits. NHTSA uses a crash-test speed of 28.5 to 29 mph and test dummies of 20 pounds--far less, in some cases, than the manufacturers’ maximum claimed weight.
It’s debatable how many children at those upper weight limits travel in the rear-facing position. Many like to face forward by the time they’re that big. Our examination of federal data found no reported severe injuries related to the problems we discovered in our crash tests.
Still, the makers of the Combi Avatar convertible seat say on the box that it can hold a child up to 30 pounds in its rear-facing position. In one crash test at that weight and at a speed of just 28.9 mph, the LATCH strap connecting the rear-facing seat was completely cut, and the seat lunged off the test rig. The same result occurred with another sample at 30.1 mph, just above the federal standard. In a third test at 29.7 mph, the LATCH strap length adjuster broke, and the seat shell cracked. The Avatar passed our crash tests with standard vehicle belts, but its failure with LATCH led us to judge it Not Acceptable.
The rear-facing Evenflo PortAbout 5 infant seat, which we tested with a dummy weighing 22 pounds, the manufacturer’s claimed weight limit, tumbled off its base when we used LATCH at speeds of 30.4 mph in two of five separate tests. With standard vehicle belts, the seat stayed put. The PortAbout 5’s poor crash-protection performance led to its overall score of fair.
The Britax Marathon convertible seat remained attached with LATCH in crash tests at the federal speed standard. But with a 33-pound dummy, the manufacturer’s maximum claimed weight, the seat tilted back excessively. We think that could happen in a real crash if the seat is not installed perfectly. The Combi Tyro infant seat also tilted back too far in crashes at its 22-pound weight limit.
Both the Marathon and the Tyro passed our crash tests with a standard belt, but their problems with LATCH somewhat reduced their overall scores.
The problems we saw in our tests highlight a discrepancy that is not widely reported: LATCH and vehicle safety belts don’t behave identically with weights at or close to the manufacturers’ limits. One possible explanation is that the LATCH strap webbing is narrower and may be weaker than a standard vehicle safety belt. In some seats, including the Britax Marathon, the belt track isn’t the same for LATCH and the vehicle belt, leading to potentially different crash dynamics.
It’s worth noting that in our crash tests we positioned the child car seat at an angle that simulates the rear seat of most passenger vehicles today. That 15-degree angle is included in a new federal car-seat standard to take effect in August. The current standard is modeled after the 8-degree, flatter seat angle of a 1970s-era Chevrolet Impala. Representatives of Britax, Combi, and Evenflo said they did not anticipate making major design changes to meet the new standards.
Problems with rebound
We found other differences among car seats when we assessed the risk that the head of a rear-facing infant would hit the vehicle’s back seat when rebounding from a frontal crash.
In one convertible seat with otherwise high marks, the Britax Roundabout, the crash dummy’s head hit the top of the test rig’s backrest when we tested the seat without its tether. With several other seats, the rebound caused the car seat to lunge severely, but the dummy’s head didn’t hit the seat. We liked a feature on the Britax Companion, a plastic bar over the front of the car seat base, which did a very good job preventing rebound.
This evaluation is not one that the government requires. Consumers Union, publisher of Consumer Reports, thinks it should be. Rebound requirements are mandatory in Australia and New Zealand, and all seats sold there have a front anti-rebound bar or a tether.
What you can do
• Always use a car seat. All states require car seats for children under 4 years old; many require booster seats for older children. Consumers Union believes older children up to 57 inches should ride in booster seats.
• When possible, position the car seat in the center of the back seat, the safest place in a vehicle, even if that means attaching the car seat with the car safety belt and not the LATCH system.
• Never install a car seat using both the LATCH strap and the vehicle safety belt. This restricts the belts from absorbing crash energy.