Would you buy a high back booster or another 5pt harness?



Ok, my 6.5 year old DS weighs 48lbs and is 46in tall. His Britax Marathon expires tomorrow, so he is in need of a 2nd seat for my DH's Jeep Wrangler. He rides in a Britax Regent in my Sienna. The Regent is huge and won't fit in the Wrangler's backseat, so purchasing another one of those is out.

I am leaning towards a Graco Nautilus since it can convert to a booster when we are ready, but I want to make sure he will actually fit well in it. I'd like to keep him harnessed for as long as possible.

Can anyone offer any suggestions or advice? What would you do?



Admin - CPST Instructor
Staff member
The Regent isn't made anymore, so another one of them isn't an option, unfortunately.

Does your husband's backseat have headrests? The only reason I would suggest a seat with a harness is because if there are no headrests, the Britax Frontier 85 has a 23" top belt guide height, the tallest high back booster out there. It also happens to have a harness that has a 20" harness height (same as your Regent).

However, there are no data showing that a harness at his age and weight is any safer than a booster. So if you'd like a booster, there are options, but a dedicated booster won't go as tall as the Frontier, and if there are no headrests, he needs the tallest booster possible for as long as possible, then he'll move into the front seat.



New member
Thank you!

I'm torn! He probably rides in my husband's Jeep maybe 2-3x's/month right now. I don't know which to purchase. His Jeep does not have headrests, so he would need to be in a HBB until moving to the front seat. We also have twin 3 year olds who just turned FFing in the Marathons - so, any seats we purchase can be passed down.

What other HBBs have a high seat belt guide height? Now I'm leaning towards the Frontier, but wish there was a less expensive option since it is not his primary seat.

Are there any other seats out there that would work?

Thank you so much!!


Well-known member
just to clarify (since he is within the weight limits of a Nautilus), a forward facing seat is outgrown when ANY ONE of the following occur:

- The shoulders go above the top harness slots
- The tips of the ears go above the shell of the seat
- The weight limit is reached

Most seats are outgrown by height and not weight.


New member
Right, he still fits in his Marathon with all of those requirements (shoulders below top slots, ears within shell, and weight) - I was just hoping to find another seat that was harnessed that he would still fit in. I wasn't sure if the Nautilus had higher top harness slots than the MA - and it is much more affordable than the Frontier - so I thought I'd check here.


Carseat Crankypants
If he still actually fits in a Marathon, he has a *very* short torso and you'll get years out of a Nautilus. There's no reason to harness for years -- a good highbacked booster is fine even now -- but you will get years in a Nautilus.


New member
Remember that the Nautilus has to be 100% on the seat. I know that the older Wranglers without headrests have tiny backseats. I would definitely test the Nautilus before I bought it. :twocents:


Well-known member
That's great he still fits so well, just wanted to point out the requirements for outgrowing since it was mentioned he might be too big for the Nautilus. :)

The Nautilus harness slots are at 18.5 inches and the Marathons are at 17 inches, so he'd still have harness room left in there for quite a while.

Looks like the highest shoulder height for the Frontier is supposed to be 24.5 inches and it's supposed to fit to 65 inches); the Nautilus is at 20-21 inches and is supposed to fit to 57 inches.

As far as dedicated boosters, the Britax Parkway is at 21.5 inches and is supposed to fit to 63 inches, the Sunshine Kids Monterey is also at 21.5 inches and is supposed to fit to 63 inches as well.

I'd probably go with a Frontier since it can be passed down and has the highest booster height, or the Parkway or Monterey.


New member
Thanks Everyone.

I'm leaning towards the Frontier, I found them on sale for $223 at babycarseats.com.

Can anyone tell me how the size of the Frontier compares to the size of the Marathon - especially where the base is concerned? The Wrangler has such short backseats, I want to be sure the base will fit securely on the seat.

Does anywhere sell the Frontier where I could go check it out in person?


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