2017 Diono Radian RXT Review: The Folding Carseat that’s Great for 3-Across and Extended Rear-Facing
See our review of the updated 2019 Diono 3RXT here
Updated 11-08-18
Recall notice: most Diono convertibles, including the Radian RXT, were recalled in October 2017. See recall details here. 2018 Diono Radian RXT models currently for sale have revised (lower) weight limits and other modifications so this review only applies to RXT models manufactured before the October recall. Updated review is coming soon.
The Diono Radian RXT fills a niche for parents and caregivers looking for a narrow carseat that can hold a big kid. The Radian line of seats is known for being 3-across friendly—when you have a tiny back seat, these are the carseats you generally look at first. The Radian R-series, the R100, R120, and Radian RXT, all have basically the same shell design but features distinguish them from each other. Diono discontinued the R100 and R120 in September 2018 and refreshed the carseats in the form of the 3 R and 3RX. This review will focus on the previous version of the RXT, but the information is similar for all the Radians and we have a review of the new 3 RXT forthcoming.
| Radian Model |
RF Weight Limits
|
FF Weight Limits
|
Booster Weight Limits
|
Features
|
| R100
*Discontinued |
5-40 lbs.
|
20-65 lbs.
|
50-100 lbs.
|
|
| R120
*Discontinued |
5-45 lbs.
|
20-65 lbs.
|
50-120 lbs.
|
|
| RXT
|
5-45 lbs.
|
20-65 lbs.
|
50-120 lbs.
|
|
Radian RXT Weight and Height Limits
- 5-45 lbs. rear-facing with at least 1.5” of carseat above the child’s head or total height of 44”
- 20-65* lbs. forward-facing with a child less than 57” tall
- 50-120 lbs. as a booster with a child 40-57” tall, and child’s shoulders must also be at or above the 4th set of harness slots
*models manufactured prior to 9/5/17 have a forward-facing weight limit of 20-80 lbs.
Radian RXT Overview
- One of the narrowest convertibles on the market: makes a 3-across much easier!
- SuperLATCH deluxe push-on connectors
- 3 crotch/buckle strap positions
- Safe Stop Load Limiter
- Full steel reinforced frame and aluminum reinforced sides
- Folds flat for travel and storage
- Lined with EPS foam
- 12-position adjustable headrest
- 5 harness slot positions
- Rear-facing tether capability
- Low profile makes loading and unloading child easier
Radian RXT Measurements:
Harness height: 9”, 10.5”, 12”, 15”, 17.5”
Crotch strap depth: 3.5”, 5.5”, 7”
External widest point: approx. 17” at widest point at shoulders, 16.5” at widest point at thighs
Internal widest point: approx. 14” at widest point at shoulders, 14.5” at widest point at thighs
Seat weight: 26.5 lbs.
Installation
Rear-Facing Installation
Installation of the Radian is either easy or hard; there doesn’t seem to be a middle ground with this carseat. In order to install the Radian rear-facing, you must first attach the rear-facing base/boot. That base will set the recline for you automatically—you will not need any rolled towels or noodles to achieve a proper angle. In fact, Diono does not allow the use of rolled towels or noodles with Radians.
For an older child who has good head control and can sit upright unassisted, the Angle Adjuster accessory can be used under a rear-facing Radian to make it more upright and give front seat passengers inches more legroom too.
The RF belt path is a closed belt path, meaning it’s enclosed in plastic. If you’ve got big hands, you’ll have trouble fitting the seat belt or SuperLATCH belt through the belt path; I’ve got average-sized hands and have trouble. Because it’s closed, tightening the belt for a tight installation is difficult too. The best way to get a carseat tight is to pull the belt in the same direction as the belt path, but with a closed belt path, you can’t. You’ll eventually get it tight—it takes you longer to do so.
Forward-facing installation
Installing the Radian forward-facing is easier than RF because the cover can be pulled away for access to the FF belt path. Vehicle buckles that are on short buckle stalks or that are even with the vehicle seat may cause concern because the seat belt will bunch in the latchplate the tighter you pull. This is normal for this carseat.
Special forward-facing concerns:
Adjustable Bottom: When installing the Radian forward-facing, models manufactured after May 2016 require that the forward-facing adjustable bottom be lowered, but only if the child is over 25 lbs. Most forward-facing children will be over 25 lbs., so that means you should lower it before installing the Radian FF. Models manufactured before May 2016 have the option of using it, but it increases your chances of a successful FF install.
Safe Stop Load Limiter: This small strap that is attached to the back left of the carseat when you first receive your Radian is called a load limiter. Its purpose is to increase the amount of time over which your child feels crash forces. If you install the Radian FF for a child who weighs under 40 lbs., you must use the Safe Stop. The Safe Stop is never used rear-facing.
LATCH Installation
The SuperLATCH connectors are the deluxe push-on style connectors, but the connectors are beefier with 4 attachment “pawls” instead of the standard 1 pawl. There is an adjuster on one side of this strap. There are storage areas at the top of the shell to store the LATCH and top tether connectors when not in use. The tether strap can be used rear- or forward-facing. While tethering a forward-facing child restraint with a harness is always recommended, a top tether is not required for this seat.
vs. 
Weight Limits for SuperLATCH
| Radians manufactured before September 2009 | 48 lbs. or vehicle manufacturer’s limit, whichever is lower |
| Radians manufactured between September 2009 and March 2014 | In vehicles manufactured after 9/1/05: use SuperLATCH to carseat weight limit
In vehicles manufactured before 9/1/05: use SuperLATCH to 48 lbs. or vehicle manufacturer’s limit, whichever is lower |
| Radians manufactured beginning in March 2014 and newer | 35 lbs. rear-facing
40 lbs. forward-facing |
Once your child reaches the weight limits for SuperLATCH, switch to the vehicle seat belt for installation, whether rear- or forward-facing.
When the carseat is used as a booster, however, it may be LATCHed in at any weight. This is because the LATCH is simply holding the carseat to the vehicle while the seatbelt is restraining the child and will be the device taking crash forces.
Center LATCH installations with Non-Standard Spacing:
Diono allows LATCH installation in the center seating position if the vehicle manufacturer allows it and the LATCH anchor bars are spaced 11-14” apart.
Inflatable Seat Belts
Diono has determined that the Radian carseats can be installed with inflatable seat belts found in Ford Motor Vehicles. This does not include Mercedes vehicles or inflatable seat belts found on aircraft.
Fit to Child
The Radian RXT comes with an infant head pillow and body support. These items are optional and you can remove them at any time.
The Radian also comes with 2 sets of harness pads: a memory foam-padded set that Velcro around the chest clip and a much longer set that are rubberized on the back with metal slides on the end. The shorter harness pads MUST be used forward-facing for children under 65 lbs. (optional for rear-facing). The longer, rubberized set MUST be used forward-facing for children over 65 lbs.
Because of the well-padded cover and memory foam in the seating area, the Radian is a comfortable carseat. It won’t fit small newborns well, even with the body support, because the bottom harness slots are too high. Most kids make it easily to belt-positioning booster seat age in the harness.
The headrest provides just enough support to be comfy without getting in the way. When the Radian RXT is rear-facing and the child is using either of the bottom 2 harness slots, the headrest must be moved to the top-most position.
When used as a booster, the shoulder belt has a tendency to get caught in the shoulder belt guide. This is more pronounced in older versions of the RXT and Diono has tried to fix this problem in the latest update. It’s a serious problem when the shoulder belt gets caught in the belt guide because if a child leans forward and the shoulder belt doesn’t retract automatically, it stays loose and floppy on the child and could lead to the child being severely injured in a crash. The belt fit and geometry is otherwise very good and even earns it an IIHS Best Bet rating as a booster, but the IIHS doesn’t measure booster fit with real, moving kids.
Cover/Maintenance/Ease of Use
The cover is well-padded with a comfortable texture. Diono recommends hand washing or a front loader washing machine. Definitely hand wash the memory foam! Line dry.
The harness adjuster tightens with a tug-tug-tug motion that may take some getting used to by some caregivers. The harness height adjusts from the back of the seat. Each strap is removed from the metal splitter plate and rethreaded through the correct harness slot. Use the slots at or below the shoulders for rear-facing, above for forward-facing. Children whose shoulders are above the top harness slots, yet still weigh less than the maximum forward-facing harness weight limit, may continue to use the carseat. For those children, the tops of their ears must be below the top of the carseat.
FAA-Approval/Lifespan/Crash Guidelines
The RXT is FAA-approved for use in aircraft. It also is a heavy restraint weighing in at 26.5 lbs., so if you do travel with it, you’ll want to use a luggage cart to avoid having to carry it. The RXT does come with a padded shoulder strap for carrying and I suggest buying another to be able to carry it backpack-style if you intend to carry it. Since the Radian seats are some of the narrowest on the market, you won’t have any problems fitting one in a plane seat AND the tray table will be able to come all the way down for a forward-facer. For rear-facing, the Angle Adjuster may make the seat fit depending on the pitch of the seats on the plane your flying. Buying a snack for the person in front of the carseat certainly doesn’t hurt ;). Remember that it can only be used with the harness on the plane since belt-positioning booster seats can’t be used on planes.
Radians manufactured before May 2016 have expiration dates of 8 years as harnessed seats, 10 years as belt-positioning boosters. Radians manufactured as of May 2016 and newer have 10 year expirations from date of purchase (or DOM if you didn’t save your receipt).
Diono recommends replacement after any crash.
Advantages
- 3 Crotch Strap Positions: Having a choice of crotch strap positions makes the harness more comfortable for bigger kids.
- Low and narrow footprint means it’s more likely to fit in tight spots.
- Padded Cover: A thickly padded cover, plus the memory foam in the bum area, makes for a comfy seat.
- Folds flat for travel and storage
- Low profile makes loading and unloading child easier
- Can be installed with Ford Motor Company inflatable seat belts
Disadvantages
(In all fairness, these aren’t necessarily problems but I list them here to inform potential consumers of specific Radian RXT issues)
- Low LATCH weight limits
- Harness Adjuster: It’s tug-tug-tug can be frustrating for some used to a smooth adjuster on an infant seat.
- Installation: Often more difficult depending on the vehicle, with a higher learning curve due to the various features.
- Snug fit of the shoulder belt in booster mode is poor; shoulder belt can get caught leaving slack.
- Heavy for a carseat designed for travel
Conclusion
The Diono Radian RXT is a solid convertible seat with great rear-facing features. Its high height and weight limits accommodate big kids both rear- and forward-facing, yet it takes up less space than many of its competitors. For narrow backseats or 3-across situations, you simply can’t beat the width of the RXT. Features like rear-facing tethering, thick padding, and solid construction make the Radian RXT a solid purchase.
Thank you to Diono for supplying the RXT used in this review!
@Sheila, no, there haven’t been any design changes yet. You could certainly try it in your car and see if it’s different.
@Kristine, I’m glad you like the seat so much! I have a solution for your rf problems. Diono sells an angle adjuster that’s used for rear-facing that puts the seat more upright so it won’t interfere with the front seats so much. It’s a flat foam wedge that’s specifically approved for use with the seat (you can’t go use just any ol’ foam wedge). Since she’s way too young to ff yet, use the angle adjuster and let her get the most out of the RXT :).
I got my Diono Radian RXT on Saturday! This thing is SO cool! I love love love that it will last the rest of my extra-tall 21 month old’s car seat lifetime! I love the profile of the sides…My daughter can easily climb in and out (after I unbuckle her, of course). I wasn’t so sure of the harness straps with all the padding, but after a couple of days I can see it doesn’t bother her and helps support her head when she falls asleep. I love that it gives her extra space, but unfortunately it is much too big to rear-face in my car. 🙁 My fiance is 6’4 and we only have one OLD car. The only seat belt that it gets a tight fit in is the middle lap-belt seat (which is the only one I could attempt to RF given that the front seats go back and forth so much) but it sticks out SO far between the seats it smacks me in the head. She was already FF in her Recaro for the same reasons, so no changes, but I figured I’d try. We will hopefully be buying a newer car in the not-too-far future! I’d like to try RF again then, and I’m sure that the RXT will accommodate!
•Snug fit of the shoulder belt in booster mode is poor; shoulder belt can get caught leaving slack.
Does anyone know if this issue has been improved by now or not? I would mainly be interested in this for my 5 year old who will still be using the harness but will definatley need to booster in the near future.
Any new imput would be greatly appreciated!
I love that it can harness to 80 lbs.
I love that it goes up to the 45 lbs rear facing and 85 forward facing – years of use to be had out of such a carseat.
I love the gray one, the black one looks too hot.
I love this car seat! It is super safe, and so pretty. I love that is suitable for all ages too. Awesome car seat.
I would love to have one of these!!! The Diono seems to always be on the list of the top recommended car seats! Time to start saving my money !
This seat is great! Would love to have one for my little guy.
I don’t live near any store that sells either so I’d have to order online and I hate having to ship something back it’s such a hassle.
Will a recaro proride fit rear facing in the middle seat of my 08 dodge caliber?
@Erica, I don’t know about the Recaro Proride. I haven’t installed one, so I don’t know how it will fit in a Caliber.
Will a diono radian rxt fit rear facing in the middle seat of my 08 dodge caliber?
The Radian has a decent shot of fitting in your Caliber, especially using the angle adjuster if your child is older. If you decide to try it out, be sure to buy from a store that has a good return policy and hang onto the box.
Hi Jessica. Have fun on your trip! I’ve fretted many times over the long flight to New Zealand, so I’m sure you’re in the same mode I was, lol. If he still has at least 1″ over his head in the infant seat, you may want to consider taking it. First, it’s lighter. Tons lighter and every ounce matters when you’re hauling all your stuff through the airport, as you know. If you do bring it, bring a locking clip (and one anyways if you bring the RXT, since it’s likely the car you install it in won’t have locking seat belts and I’m assuming you’re not taking the base to the Snug). The Radian won’t fit rf on the airplane anyway but straight upright simply because of the pitch (front-back space) of the airplane seats. It was designed specifically for air travel, but that doesn’t mean “comfy” air travel, lol. You can always try installing it rf and if it doesn’t work out, turn it ff. Or rf it while he’s awake, then turn it ff for sleeping, which is counterintuitive, but everyone has got to sleep on the flight or it will be miserable. Anyway, have a good flight and good job buying him a seat too!
Hello! After SO MUCH deliberation, I finally decided on the Radian RXT for my son’s new carseat. He’s just about 14 months and still has a little time left in his Graco Snugride 35 (a month ago he was about 26 lbs and 30″), but I wanted to go ahead and get his convertible carseat before suddenly realizing he has surpassed the Graco’s limits (we’re stationed overseas, so it can take over a month to get a carseat ordered from the states). Also, we’re about to make a trip across the ocean to visit family this week, so I thought it would be a great carseat for multiple reasons: 1. If the passenger in front of him wants to recline his/her seat, it is possible to forward face the seat, unlike the Graco. It’s an 11 hour flight, so there is no way we’ll actually be buckled in the whole time – we need to move around some! – but once the carseat’s installed in the seat securely, it should be easy to snap him into the harness when we need to be buckled. On the last long flight we unbuckled the rear facing Graco (he could still sit and play and sleep in it at kind of an upright angle) so the guy in front of him could recline for the middle of the flight. 2. It’s the seat most likely to fit if our armrests are fixed. Once we got bulkhead seats on a short flight and I thought it would be the best place for us, but then the Graco wouldn’t fit between the armrests.
We’re trying to get bulkhead seats this time with the skinnier carseat to minimize inconvenience for everyone and allow us to possibly rear face the Radian RXT, but they seem to be particularly difficult seats to get and I don’t think it’s going to happen for us. I installed the Radian RXT in my 2009 Dodge Journey today and realized how tall it really is! We definitely need the angle adjuster if my husband is going to sit in the passenger seat. It’s so big, I’m not so sure we’ll be able to rear face it on the plane no matter where we sit (I assume trying the angle adjuster on the plane would be a no-no?), and I am wondering if I should just bring his Graco. It’s definitely lighter, we’ve traveled with it before, and it’s more likely to be able to rear face in regular seats, but if it doesn’t fit rear facing, we have no other options with it. Do you have any tips for airplane travel? We want to be safe (that’s why we bought him a seat for his carseat), plus have somewhere to put this hot, heavy, wriggly baby besides our laps. I’m not sure which carseat to bring!! Just wondered if you had any advice. 🙂
Just the Combi Coccoro at 15″/38 cm, but it’s such a small seat that it most kids outgrow it forward-facing at around age 3.
thanks heather so disappointed is that with sides up really thought this would fit 🙁 is there other smaller car seat available?
Cheeky, forward-facing together, the Radians are a little over 86 cm. The next closest “narrowest” seat would be a Ride Safer Travel Vest. Version 2 of the Travel Vest has a tether, though it’s optional with a lap/shoulder belt. https://carseatblog.com/21235/ride-safer-3-travel-vest-review/ I don’t believe there’s any difference between the tethers found on Australian carseats and those found on the Radian, though keep in mind that the Radian can’t be tethered *rear-facing* to the tether anchor toward the back of the vehicle; it must be tethered toward the front of the vehicle. But that’s moot since you’re looking for a forward-facing seat. You’ll be able to tether the Radian forward-facing normally.
also is the tether clip the same to the Australian one I cant see it in the photos , I just bought a Holden Captiva 7 2013 and there is 3 points behind the middle 3 seats but one needs to fold forward to allow my other 2 kids to go to the back seats so that’s why im limited for space and only have 79cm thankyou so much.
hi heather sorry should have mentioned forward facing side by side lol but needs to be 79cm in width together ,Australia is pretty strict now with tethering so I wasn’t sure as to the US laws on that
@cheeky, perhaps your accent is throwing my off, lol, but I’m confused about your tether question. All Diono convertibles, including the RXT, have top tethers, so that shouldn’t be an issue for you. Are you talking about the ability to tether it rear-facing “Australian style” as seen in pics here, https://carseatblog.com/12749/how-to-use-a-rear-facing-tether/ ? It can’t do that because it has a single tether strap as opposed to a V-shaped tether strap.
hi im in the market for new car seats but iam limited for space I have 79 cm (31”) and about the same in height I need to fit two side by side and was hoping the diono radian rxt would be ok, I also live in Australia and need it to have a tether to anchor to the car . I have more space at the back of the car but no anchor points 🙁
@Emily, your comment brings back bad memories of our last flight to New Zealand when they didn’t pick up our food trays for about an hour and a half after dinner was served. We juggled trays as the family got up to use the bathrooms and try to get comfortable to sleep for the night. Ugh!
THANKS for mentioning that when used in an airline seat the RXT allows for the tray to be folded down. This was the deciding factor in which car seat to bring on our tri-continental travels this summer for our 2 year old. I will haul the heavier seat on and off the plane if it means he can have a tray table!! I know a minor detail, but after flying in the past with a 2 year old on a trans-atlantic flight in a Britax where we could NOT use the tray, I know how important that detail will be for our sanity when the time comes!
@Mia, pretend that the back of the carseat is a wall and your child is resting against that wall for you to measure his height with a ruler. Take a ruler or other straight item and rest it against the top of his head so that it aims straight back to the seat. It’s just like he’s standing against a wall, but the carseat is laying back at an angle.