Diono is one of my favorite car seat manufacturers now, as they’re determined to make it possible to rear-face for longer in the United States, and that’s the single safest position we can place our kids in. I’ve reviewed their latest convertible models, the Rainier, Pacifica, and Olympia, and have been thrilled with all of them. However, their older flagships, such as the Radian RXT, Radian R120, and Radian R100, are still excellent seats that can keep the average child rear-facing until s/he turns at least 4. The RXT, R120, and R100 also have several advantages over the three current Diono seats, including being cheaper and being the narrowest convertible car seats you can buy. This review’s on the Radian R100 and why it’s worth considering as a cheaper alternative to the previous seats I’ve reviewed.
Over the last year, there’s understandably been a ton of buzz about the Diono Rainier, Pacifica, and Olympia. The first two seats are two of only a handful that allow for rear-facing until 50 pounds, while the third seat is still one of the best on the market right now with a 45 pound RF limit. However, the Diono Radian R100 is still well-worth considering for anyone interested in a 3-across friendly, extended rear-facing capable convertible car seat.
Technically, it’s an all-in-one convertible car seat, which means you can use it rear-facing for infants, toddlers, and preschoolers, and then turn it forward-facing to use during the elementary school years, and then even use it for a while as a booster seat. It’s a slightly older seat than a number of seats on the market right now, but it’s no less safe and should definitely be considered by every parent shopping for a new car seat.
Like the R120, it’s basically the same seat as the RXT except without the head support. The main differences between the R120 and the R100 are that there are slightly lower weight limits present in the R100. Oh, and it costs significantly less. You can skip down to the “Why Buy the Diono Radian R100” section if you just want a summary of why it’s worth it.
Diono Radian R100 Limits for Weight and Height
Rear-facing: 5-40 pounds with a 44″ height limit. There is also a 1.5″ height limit relative to the top of the head rest; your child’s head can’t come within 1.5″ of the top of the seat, to put it more directly.
Forward-facing: 20-65 pounds with a 57″ height limit. Diono stipulates a 1 year minimum for forward-facing and suggests waiting until s/he reaches at least 2. However, best practices suggests rear-facing for as long as possible. I recommend doing so at least until 4, which is daily practice in Sweden, where the fewest young children die per capita in car collisions. Here’s an article providing tips to keep your toddler rear-facing, if you need additional support making it possible.
Booster mode: 50-100 pounds with a 57″ height limit. The R100 is the same as the other Diono convertibles and all-in-ones in terms of the requirement that your child’s shoulders reach the 4th pair of harness slots before you use the R100 as a booster seat. Remember the 5-step test is your go-to-guide for determining when a child is ready to stop using a booster seat and start using a regular vehicle seat and seat belt. If your child doesn’t pass it, and most children won’t until they’re typically 10 to 12 years old, s/he’s not yet ready to sit safely without a booster.
Dimensions of the Diono Radian R100
The R100 is 17″ wide at its widest point, making it one of the best convertible seats on the market right now for 3 across compatibility. It weighs approximately 26 pounds. The internal width is around 14″ at the shoulders and a bit more down at the thighs.
Using the Diono Radian R100
When you unbox the Radian R100, you’ll notice that it’s collapsed, which makes it easy to attach straps to it and carry it about like a backpack. This comes in handy if you’re traveling and need to use it in a portable situation like in a taxi or on an airplane. Of course, it’s FAA approved and airplane compliant as a result. The LATCH straps are stored on the back of the seat, as well as a seat belt clip that you might need when installing the seat in an old car that doesn’t include a locking seat belt. The seat is a solid one, and it makes it easy to see the lineage of the later Dionos when examining it.
When installing it for the first time, keep in mind that you might need to adjust your harness straps to make sure they’re even. You have 5 shoulder harness positions to choose from, and there is a recline base that you need to use while rear-facing. Due to the wide range of harness slots and the good span of harness height, most children will find a position that fits them well while using the seat. The harness is unfortunately not a no-rethread design, but is still reasonably easy to adjust. To adjust it, you go behind the seat, pull the straps out of the splitting plate, and thread them into the harness slot you’d like to use.
When rear-facing your child, you’ll need to make sure the harness straps are either at your child’s shoulders or below them; when you’re forward-facing, the straps need to be above the shoulders. However, Diono does allow you to forward-face with your child’s shoulders above the highest shoulder harness slots as long as your child keeps within the weight limit for forward-facing and still has the tops of his or her ears below the highest part of the car seat. This is unique to Diono and shouldn’t be done with other seats.
In many of my 3 across car seat guides where I reference Dionos, I’ll also reference the angle adjuster you can buy for them. It’s cheap, it’s compatible with all of the Diono all-in-one and convertible seats, and it helps you reclaim a bunch of front-cabin space that would otherwise be compromised by the seat. It’s definitely a good idea to pick one up if you’re in a shorter vehicle (anything under about 190 inches) or if you’ve got taller drivers or passengers. The last thing you want to do is forward-face early because your child seat is a pain to use.
Why Buy the Diono Radian R100?
This is my favorite part of any review. To put it simply, I’d buy the Radian R100 because it offers many of the benefits of the more expensive Diono seats while costing a bit less. It allows you to rear-face your child for up to 40 pounds. That’s not nearly as good as it gets anymore, as there are a number of seats that will allow you to rear-face until 45 or even 50 pounds on the market, but it’s still good enough to get many kids to 4 while rear-facing. Remember that the longer you rear-face, the safer your child is. While parents tend to forward-face at 1 in the US, in Sweden, it’s not done until 4. As a result, it’s quite rare for a young Swedish child to die in a car crash. This here is why I’d buy the Radian R100.
How does the R100 compare to the R120, RXT, Rainier, Pacifica, and Olympia? (A short Diono convertible comparison)
Besides that, I’m also a fan of the steel frame in the Radian R100, although I wish it had the aluminum reinforced head rest for additional head support as well as the EPS foam around the head for side impact protection that you get with seats like the Radian RXT and Rainier. You also get shallower sidewalls in the R100 compared to in seats like the RXT, Rainier, Pacifica, or Olympia, which results in slightly less side protection. If this matters to you, get the RXT, Rainier, Pacifica, or Olympia. If it doesn’t, get the R100 or R120. If you want to rear-face past 40 pounds and you want to do it in a Diono, go with the RXT, R120, Rainier, Pacifica, or Olympia. If you want to rear-face past 45 pounds in a Diono, your options are the Rainier or the Pacifica. If it doesn’t have to be a Diono, you can also choose between the Fllo and the Foonf.
In short, the Radian R100 is an incredibly narrow (17 inches!) seat that will make it one of a small number of seats possible to install 3 across in just about any vehicle. It’ll let you rear-face until 40 pounds and it costs less than any other Diono convertible on the market. It also has a 10 year lifespan as a booster and an 8 year lifespan when used rear- or forward-facing, which is about as good as it gets right now for a harnessed seat.
The Radian R100 is a great car seat and, in my opinion, still one of the best you can buy today in the US for children between zero and four. You can buy the Diono Radian R100 in Shadow and Storm fabrics here. Canadians can buy the Radian R100 here.
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