Can you use LATCH and seat belt?

If the LATCH fails, then it will have at least done the job of precrash positioning so yes, the seatbelt WOULD be a good backup system. There's no real world data yet showing that using both systems is harmful (as much as I've tapdanced around saying it in the past, making up reasons to fill in the blanks of 'why not?' left in the manuals...).

Elizasmom said:

If the LATCH anchors failed, the seatbelt should still hold. I'm not disputing that there may be issues with what I'm doing and that I should probably stop, but I don't see how you can say that the belt would also unbuckle itself just because the LATCH anchors did.

If the LATCH anchors were defective and broke away, I'd be very glad to have belted it too. I don't see how there could be any worse situation than nothing at all holding the car seat in. However, if there are risks associated with doing this, I have to weigh that against the unlikely event that it would be a benefit.

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Consumer Reports explained it this way:

• Never install a car seat using both the LATCH strap and the vehicle safety belt. This restricts the belts from absorbing crash energy.

safeinthecar said:

I've posted this explanation in other threads, so I'll just cut and paste it here.

...

Problem with the seat belt:

The seatbelt sat at an unlocked angle against the car seat base. The female end seatbelt could not be twisted or shortened with a belt shortening clip as it was encased with a plastic sleeve.

Therefore this rock solid car seat was not actually installed in this car at all.

This particular example is not the only time I have seen this kind of thing happen, it just sticks in my mind because it was the first time I saw it.

HTH,

Kimberly

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I'm trying to follow this, as I need to upgrade our car seats, but I do not understand how the seatbelt not being secured (by twisting or using a clip) means that the car seat is "not actually installed in this car at all". Could you help me understand this?

Thanks!

onlydarksets said:

I'm trying to follow this, as I need to upgrade our car seats, but I do not understand how the seatbelt not being secured (by twisting or using a clip) means that the car seat is "not actually installed in this car at all". Could you help me understand this?

Thanks!

Click to expand...

She's referring to a specific type of seatbelt. Some seatbelts lock at the buckle with a locking latchplate. The belts need to be perfectly parallel for the seat belt to lock, otherwise they can slide loose. If the belt path of the carseat forces the buckle to lie in an unnatural position, then the locking latchplate is NOT locked.

A good cure for that in some seats is to twist the female buckle so that it lies in a lockable position, but since this car's buckle stalks had plastic trim around them, that couldn't be done.

OK, I see. I interpreted the post I quoted as being a global explanation for why LATCH + seatbelt will not work. In fact, it was a description of why a particular LATCH + seatbelt installation was, in fact, not secured at all. Thanks for the clarification!

That being the case, it sounds like the only explanation is that the two systems used together may impact the ability of either one to adequately absorb the force of impact, and, because manufacturers don't perform tests with both systems use simultaneously, it's impossible to say that it's safer, and, in fact, it may be less safe. Hence the "do you want to make your child a crash test dummy" comments.

Is that about right?

Thanks!