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!
Do you know if we can fit two radian rxt or r120 in a 2010 dodge caliber?
Even with the angle adjuster it still would not fit. I kept it for DH’s truck and got a Britax Advocate that fits much better. Thanks for the advice about forward facing too.
@mcregan, if your child is old enough, you can try using the angle adjuster to make the RXT more upright if that’s the problem. Also, with your Volvo, you may want to try these taller seats forward-facing too before you buy (or hold onto those receipts!). You’ll run into problems with your headrests with some taller carseats.
I bought the Diono RXT because I loved the design and safety features. I drive a 2008 Volvo XC90 and this car seat does not fit rear facing in the car. I tried to put it on each side and in the middle and there is no way for it to fit. I am bummed out because I really loved this seat!
@ILS, have you tried using a tug-tug-tug method to tighten it? How about pulling the harness snug from behind, then pulling the slack by pulling the adjuster strap?
We have a Diono RXT and absolutely love it, but we have issues tightening up the straps. It seems like such a struggle to get it tight enough. Loosening it is fine. Other monthers in my baby group with the Diono RXT also have been experiencing the same thing. Any tricks? or should we call the company?
We have the angle adjuster and he is rear facing, 16 months and 23 lbs.
Thank you for the amazing review!
ILS
I have a Nissan Juke. 5 month old that weighs 20lbs. Do you think this would fit RF in car when reclined ?
@Charlotte, the side protection is in the headwings. There isn’t a lot of torso protection, which is why the seat folds so easily for both storage and travel. If you’re looking for side impact protection, a seat with deeper sides may be something you want to look for.
I have been looking at getting one of these seats for my 2 year old, so we can move our 6 month old into her Britax… BUT my husband and I both look at these seats and the first thing that pops into our heads is “Where is the side protection?” It just seems so open at the sides! Does it seem protective enough in person?
@ Chelsea – you received some excellent advice from snowbird (who is a Canadian CRST Instructor-Trainer). If possible – can you start a thread and post some pics of the current install on our Canadian forum here: http://www.car-seat.org/forumdisplay.php?f=17
hi Chelsea, it sounds like the tech who helped you gave you some information that isn’t in the manual or any official literature. In fact, it is the first time I have seen this mentioned and I am surprised that you were able to get it completely within the belt path as I have never seen that with a rf’ing radian install before.I would suggest not doing this, and if the seat isn’t staying tight on it’s own, then switch to a seat belt installation.
I would also recommend taking pictures of the damaged plastic and getting in touch with Diono to see if they’re comfortable with continued use of the seat. It sounds like significant stress has been placed on the belt path during the installation. (If the UAS belt hasn’t already been replaced, then I’d suggest installing with seatbelt now anyways. While the cracked plastic part of the adjuster may not affect anything, it could potentially and I would be uncomfortable using it for an install with it being damaged.)
I’d also suggest getting in touch with the technician and telling them of the damage to your seat as a result of his/her information. Who knows how many other people have been given the incorrect information. 🙁
Hello! I have my son in a radian RXT and LOVE LOVE it. He is RF (2yr5mo, 31 lbs) When I first installed the seat, I went to a tech to guide me 🙂 She told me to be sure that the adjuster on the UAS latch system was INSIDE the belt path. Now, this IS possible, but its hard! This last time I was installing, it put so much pressure on the plastic part of the adjuster that the plastic actually cracked 🙁 And I also notice that the plastic on the seat (the side of the belt path where the adjuster slips in when tightened) has some pretty deep gouges in it. Im just wondering if its really necessary to have the latch adjuster inside the belt path. The tech i went to was concerned that if my sons foot was to push on the adjuster he would loosen the UAS belt. HELP! Thank you for any info…
@Melissa. I think you can do the Radian in the Corolla, especially with the angle adjuster accessory. I can’t comment on the ability to adjust the harness, but the True Fit would have the advantage there since it’s a continuous harness and you could loosen one side at a time.
LOVE your reviews; I have a few bookmarked for DH to read.
Our car: 2006 Toyota Corolla. One car family, rarely need to move seats.
Our kids: 4 y/o son ~40 lbs. ~40″; FF in an Evenflo Triumph Advance behind driver seat.
One-year-old son ~22 lbs. ~29″ RF in 2006 Britax behind passenger seat.
We’re shopping for the next seat. I can’t for the life of me decide between this one (Radian RXT) and The First Years True Fit Premier. I am concerned that the True Fit Premier might not fit RF in our car. But I’m concerned about being able to properly tighten the Radian RXT while RF. Neither car seat is available at any retail stores in our area so we’re going to have to order online. Can’t afford to order both at once.
Also, we’re flying (1st time with kids, whee!) and taking a train in a couple weeks and need to have new seat by then.
Was thinking about putting 4 y/o FF in new Radian and 1 y/o RF in Evenflo…
Looking forward to your advice, thanks in advance!
@Kathleen, it’s been a while since I did the search, but it’s possible I searched for only the Mini Cooper on car-sear.org. Can you elaborate more on the fit in your car? How much space does it leave you in the front seat? Is it installed with LATCH or the seatbelt?
@Jennifer, kids do crazy things with their legs. My dd’s favorite position in her ’02 Marathon was to flip her legs out and over the edges–real lady-like, lol. In a crash, the legs will fly up so fast, it’s not likely they’ll be caught between the carseat and the vehicle.
Hi, thank you for all the really helpful information. We are trying out the Diono Radian in our car right now and I like everything about it but have one concern. Because the seat is low and doesn’t come up on the sides my son (18 months) puts his feet over the sides of the seat sometimes. I worry in a car accident if his feet would get crushed. When they talk about side impact safety are they just talking about head safety? What was your impression of leg and body safety when you tested the seat. I would greatly appreciate any response you could give on this.
Heather,
We have been using an XTSL for almost a year now with my 2 yo. We now need to get another carseat for the grandparents. I wanted to get another XTSL, of course, so I’m looking into the Diono RXT. One of our vehicles is a Mini Cooper Countryman–the four door/four seater Mini. The XTSL fits in the Countryman fine. In an earlier post you indicated that the RXT may be problem in a Mini Cooper Countryman. Is the RXT bigger than the XTSL? What makes it not fit in the Countryman when the XTSL does?
Kathleen
Brad, she was about 53.5″ back then and is short in the torso. The headwings do sit lower in booster use, so if that’s a concern, one of the other models may be better for you.
Thanks for the very helpful review. Perhaps a bit of an odd question: Do you know about how tall your daughter was at the time of that picture? We have a little guy who is in the 99th percentile for height, and one of the criticisms of this seat that I have read elsewhere is that the head wings can be too low for tall children when they move into the booster phase. Just trying to gauge (as best one can) whether that would be a problem for us with this seat.
@Phyllis, if your SnugRide is a tight fit, the Radian will be too unless you install it using an angle adjuster. Diono’s guidelines for the angle adjuster are that the child must be over age 1 before using, so if your child is over age 1, then it’s a solid option for you and could buy you several inches of installation room. The Peg Perego convertible is another good option that installs more upright. Did you see our review? https://carseatblog.com/16793/peg-perego-primo-viaggio-sip-5-70-convertible-review/
Hi, thank you for your review. I want to get the Diono Radian for RF use in our 2002 Acura EL. Currently, our graco snugride is a somewhat tight fit. Wondering if you would know how/if the Diono would fit?
Help! I have a 2002 Audi A4 car. I have a four year old who I plan to take out of his Britax Marathon (Bought in ’06) and plan to put my 16 month-old into that rear-facing. I am considering having a third child. I believe that my two top choices for my older child at present are the Diono Radian 120 or the Britax Frontier 85. For space, I would more consider the Radian, however, I notice that it did not get rated by the iihs.org. I think I prefer the Britax for familiarity and since it was reviewed by iihs, but would like some advice. Finally, we do not have LATCH since 2002 was the last year before it was required. I travel a few times a year, so installation is of consideration. I so appreciate the work you put into helping us parents keep our kids safe. Thank you for your help!
@Ashley, yes, you can use the angle adjuster with the rf tether.
I have an rxt and was wondering if you can tether rf’ing and use the angle adjuster?