Why can't you LATCH and secure with vehicle seat belts?

[cimberdog]

My husband and I are wondering how come you can't install a car seat using LATCH and the vehicle seat belt? So for example, we bought a Graco Nautilus and we cannot get it tightly installed in his Subaru Tribeca using the seat belt. It slips out every time and we've tried every trick we know. So then we wondered, why can't you LATCH it AND install using the belt path? The LATCH would increase the stabillity of the seat, would it not? And then we'd use the seat's harness to secure our son.

Just to clarify, we are NOT doing this - DS#1 will be six in two weeks and we've determined that given the space in the Subaru (this is next to a Regent) and the issues of installation, we're going to use the Nautilus in HBB mode and secure to the car with LATCH to hold it in place, but then use the vehicle seatblets to secure our son into the seat.

Just wondering why you can't do the LATCH and belt installation...

Also, in his Subaru there is a LATCH weight limit of 60 pounds, but is the Regent only LATCH-able until 50 pounds? So when our youngest reaches 50 pounds we need to use the belt installation (dreading that right now...)?

Thanks!

[Judi]

Since it has not been tested with both, it shouldn't be used. Does your Subara have a locking latchpath or switchable retractor? What year?

[LISmama810]

We don't know exactly why you can't--whether it hasn't been tested that way, or whether it has been tested and failed.

One theory is this: In a crash, the seatbelt or LATCH straps will stretch a little, which is actually a good thing. This helps the seat (and the child) "ride down" the crash. If the seat didn't move at all, all of the force would be on the child (and the child's internal organs). There's some thought that if you use both the seatbelt and LATCH, neither one will work in the way it's supposed to (i.e., they'd restrict each other). That's just a theory though.

The Regent has a 48-lb LATCH limit, so you'd have to stop LATCHing at that point, though you MUST use the top tether after 50 lbs. It is generally recommended that you use the top tether regardless of the car's weight limits. The top tether isn't a primary restraint for the car seat, so it's usually considered acceptable to exceed the LATCH limit for that--but not the lower anchors. IF the top tether were to fail, it would likely do so after it had performed its job.

[Defrost]

Another problem I've seen with this type of install is that neither one is correct, even though the seat seems tight.

For example, in your situation - if your child is over the weight limit for LATCH, but you use it and the seat belt both, it's still not fixing the actual problem, which is that the seat belt install isn't good enough. If LATCH fails because it's being used over the weight limit, then you're still stuck with an improperly secured seat belt install, see? Or maybe it wouldn't - who knows? That's the problem, though. The whole point of using a carseat is so that we KNOW as much as humanly possible what will happen to our kids in a crash. :)

I'm not familiar with your vehicle, but if you tell us more about the problem you're having, we might have some tips that will help you get a good, tight seat belt install.

[Kat_Momof3]

Plus, didn't consumer reports (not typically helpful, but in this case, they were) test some seats that way and found out that each kind of affected the other so that neither absorbed the forces properly a few years ago??

But suffice it to say that Latch was designed to take the place of the typical seatbelt install, not to add to it.

When something is not allowed by a manufacturer, you can only take in the result that either they tested it and it failed, or it hasn't been tested.

if it tested and failed, you really don't want to be doing it.

if it hasn't been tested, do you want to make your child the crash dummy??

Have you tried installing using the locking clip??

[Shanora]

Since your having a hard time getting a tight install with the seat belt why not use the latch to help assit you in getting the seat belt tighter. Install with the Latch, tightly, so there is no movement, then install with the seat belt (you might be able to get a tighter install with the belt since the latch is already tightend). Once you get the seat belt in there tightly, loosen off the latch and unhook it and tuck it away so it doesn't become a pojectile or whatever. You install should be good and tight with the seat belt now.

Just remember to unhook the latch, cause you really don't want to risk them not working properly if you have them both used.