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!
we’re having trouble finding a car/booster seat that really does “boost” up our granddaughter so that she can see out of the back windows in our Hyundai Tucson. Any suggestions?
Teri, how old is your granddaughter and how much does she weigh?
Hi, can you comment on a couple of questions:
Are Diono carseats compatible with Subaru Outbacks? I’ve seen mixed reviews elsewhere about getting a good install, both rear and front facing, due to the Outback’s raised seat bight.
Would you buy a Diono seat or a Graco 4Ever? I like the Dionos’ narrow and low profile, but the Graco seems easier to use. I don’t need 3 seats across, although it would be nice to have the option. Both seem to have good height and weight limits. My youngest is 15 months so newborn fit is not an issue.
Thanks!
Hi Julie. I don’t think you should have a problem with the Diono in the Outback. Just be aware that it’ll take up a lot of room front to back and the 4Ever will have a smaller footprint. The 4Ever will also last longer rear-facing if that’s your goal, but because of the higher sides, it will be a little harder to load and unload your child.
Help!!! The harness straps were completely removed for cleaning and now we cannot get them back in. No human hand can get the right angle to feed the strap through the teeny tiny opening after removing the screws and cover. How do we re-install??? Also can we get a safety strap from the website? We have a 2012 Radian
Hi-
Looking for advice — we have twin 8 month olds and a toddler. We drive a 2013 Acadia, that has captains chairs as the second row, and a full third row. We would have the twins rear-facing for another 16 months in the captains chairs. Would it be a great difficulty to access the third row to buckle in our toddler with the 2 RXT rear-facing?
Hi Kelly. How do you access the 3rd row right now? Practically, I don’t see this working without at least one twin in the 3rd row leaving one of the 2nd row captain’s chairs free for moving/tumbling forward to access the 3rd row. Can you remove one of the captain’s chairs for the time being until your toddler is old enough to buckle in reliably?
Then you may want to look at this list of carseats for the 3rd row: https://carseatblog.com/22818/the-ultimate-rear-facing-convertible-space-comparison-review-size-matters. The Radian may or may not fit in your 3rd row with the angle adjuster, but other seats like the Britax Boulevard ClickTight may. Definitely try before you buy if you can.
Hi, great review. What are your thoughts on the RXT Vs the R100? I have a double cab Tacoma truck and am limited on space. I will get the angle adjuster too.
Also, we will travel by air with it so like the fact the R100 looks like it can be worn backpack style but for the RXT you have to purchase additional strap.
Thoughts?
Hi Joe. The RXT and the R100 have the same shell and differ by the head wings and weight limits. If your child doesn’t need the higher weight limits the RXT offers, the R100 is a good choice because the lack of head wings gives a little bit more growth room for height. On the other hand, the head wings do offer the head protection in a crash.
The carry straps for carrying either seat through the airport are sold separately as accessories, so you can either buy one and sling the seat across a shoulder or buy 2 and wear it backpack style.
TBH, I know the Tacoma has a small back seat, but it should fit in the middle OK and the angle adjuster definitely will help. Just be sure that wherever you purchase it from has a good return policy just in case you need to return it.
I recently purchased a Diono Radian Rxt, but it remains in the box as I’m conflicted. I have a 2011 VW Passat and I’m worried about the installation as the seats have a decent cushion angle. I also have a Britax frontier clicktight in DH’s car that is super easy to adjust. But, I don’t know if the install would be just as difficult in the Passat. Any information on how I can evaluate the seat for the car without opening before I lose the ability to return it would be so helpful! Thanks in advance!
Some stores like Buy Buy Baby will let you take the floor model to your car to test it out. Also, did the store you purchased it from say it has to be in an unopen box to return? Some places let you return as long as you have all the original packaging, but it can be opened.
Kate, Jen had some great advice for you! If your child is older, you can also buy the inexpensive Diono angle adjuster to help make the RXT more upright if needed.
I really want to like this and get it, but the lack of side protection especially for the legs really bugs me. In just about every picture with a child over 2 and FF, their legs are hanging off to the side instead of straight ahead. In the event of a side impact crash, I can only imagine what will happen to the limbs.
Am I alone on this or is it a valid concern?
FYI: the Facebook connect button is not working.
I think it is a valid concern, but unfortunately we have zero studies on the efficacy of side impact features even for the head, let alone the torso or legs. Some parents do appreciate the lack of a pedestal combined with the lower sides on the Radian models that makes it much easier to load and unload kids in some situations. Mainly due to the number of excellent newer products on the market, we now generally recommend the Radian for narrow seating positions and for installing adjacent or 3-across carseats. In some situations, the Radian is one of the only models that will work. For other situations, we feel there are many carseats that are much easier to install and use, and have taller height limits that allow them to be used longer.
My daughter is about 31-32 inches tall and on the 3rd harness position. Directions say if on the first two lift the head wings all the way up. So if she is on the 3rd and still the wings do not come down far enough to reach the bottom of the cheek bone.. What should I do… Leave them up or down. Someone told me something about removing a square piece from around the wing but didn’t get enough detail. Could you tell me what best to do at this point our if you know of the square piece mentioned? Thank you
I recently purchased a 2013 Kia Sorento with a third row. My kids are in radians. I want to install the car seats FF in the second row of the car and leave the third row for adults. There are only 2 ways to get to the third row: climb in through the trunk or fold down the second row. I am wondering if it is possible / ok to fold the radian while it is installed in the vehicle seat (to fold the vehicle seat as well). Does that make sense? The tether anchor is on the back of the vehicle seat. I appreciate any info! Thanks
Amanda, you could try it, but it would be hard to do I think. I think the tension of the belt (either seat belt or LATCH) on the belt path would be enough to stop it from folding. I won’t say no definitely because someone will come along and say that they did it, lol. Does your vehicle seat tip forward entirely as it slides forward? That’s how the Nissan 2nd row seats work that can leave the carseats installed while giving access to the 3rd row.
Hi, I have the diono radian and just recently I have forward faced my three year old. So today I went to strap her in and I pulled the strap to get it over her shoulder and it pulled right out! I was terrified! Has anyone else had a problem with the shoulder straps coming off the metal hook ( not sure what it’s called)?
Are you able to use inflatable seatbelts?
Hi Cassie. Diono doesn’t allow installation with inflatable seat belts.
Hello, I have a Rainier and have been reading about installing it in the center of my backseat because it has been proven to be safer. I, then, read that many carseats you cannot use LATCH in the center seat because it will actually cause harm if in an accident. Do I use LATCH if I have my Rainier in the middle seat? Is it ridiculous to put my 3 ½ yr old in the middle seat of my BMW sedan, or is it truly much safer? Thanks!
Thanks so much for this amazing review! I haven’t seen the issue you wrote about the head wings and the seatbelt mentioned anywhere else, so I’m glad I found your review. I’m wondering if the R120 would have the same issue, since there are no head wings?
Right, Maryanne. The issue is different with the R120; it holds the seat belt in better position, but it holds the seat belt off the child’s chest. Diono convertibles can be used as boosters in a pinch, but for everyday use, I’d buy a dedicated belt-positioning booster.
What about using the R100 in belt positioning booster mode? Sorry if I missed a post about it
Jen, the R100 and R120 are essentially the same seat with different weight limits, so it would be the same issue.
curious, the review was posted in 2011, do the issues with the headwing and using the rxt as a booster seat still exist in 2015. have you posted any new updates or blog post since on the radian,
regards
Mike, yes, it’s still the same design and Diono used the same design on the Rainier seat as well. I’d consider the Rainier review to be a kind of update since it’s based on the RXT shell, but is a little wider in the torso area. https://carseatblog.com/29939/diono-rainier-review-diono-adds-depth-to-its-convertible-lineup/
Anyone use this seat with an infant with GERD? My 4 month-old is quickly outgrowing his infant seat and I’m considering this as his next seat.
Becka, because the RXT is an L-shaped seat as opposed to a more cup-shaped seat, it should be good for a GERD baby.
Hey there Heather. Glad to have accidentally found your blog (through link from ClubLexus forums discussion). We are going to have a 3rd baby and my lovely wife currently drives the Lexus RX350 with no third row seating option (but a larger trunk space). The oldest kid is soon to turn 6 and sits in the backless booster seat. The pretty Yunna (4 yr old girl) is in the Britax Marathon (fairly wide but comfy for her 50 lbs size). I saw this discussion re: Diono and in reading through carefully saw you mention the RX330 and 3 seats in a row option, which my wife tells me is not doable. I would love to have a larger SUV/minivan, but at the current time it wouldn’t not be the best use of financial resources available. The question is what type of a car seat is depicted on this photograph which you used in this blog (beige color in the center?) https://carseatblog.com/wp-content/uploads/2011/10/Radian-RXT-3-across-in-RX330-225×300.jpg Looks like it might work next to the Britax or maybe on the side with booster seat/base going in the middle. Thanks in advance for the reply. If you have any other suggestions or ideas, I am listening.
A client just got a new seat. She asked me, “can you tell me what the rubber backed harness pads are for? They say that they’re for use with kids over 65lbs, but what do they DO? I went through the instruction manual three times and can’t find anything about them.”
I am unable to find the info either. Do you know?
Mary-Rose, they aren’t addressed in the instruction manual. The directions for their use are sewn inside one of the harness pads. They’re designed to improve head excursion scores in bigger kids (well, on bigger dummies in crash tests). I have pictures of them in my Rainier review: https://carseatblog.com/29939/diono-rainier-review-diono-adds-depth-to-its-convertible-lineup/ .
Are the rubber backed strap covers not suppose to be used under a certain weight? Are they only to be used forward facing?
Please help!!!
I’m leaning towards the RXT but I’m wondering if anyone can provide feedback on the RD position on a small car (the seat will be on a Nissan Versa)
Also my children is very tall so this is the main reason why I’m leaning towards this car seat.
you can purchase another attachment for the car seat its a square phone please its about $10 I ordered mine from Bye Bye Baby you install the carseat rear facing like usual then after everything is secured in place you lift the seat forward and slide the phone piece under the car seat it will lift the seat up slightly so that you have more room behind the actual seats in the car works like a charm I set mine just fine in my explorer but in my husband’s Chevy Silverado there’s not enough room for the seat it hangs clear into the front seat area but with the phone peace it set up just fine and leaves plenty of room for us to move around in the front
@daji, I think your phone autocorrected “foam” to “phone,” lol. Yes, Diono has an optional foam piece called the Angle Adjuster that can be slipped under a rear-facing Radian after it’s been installed. It can be used once a child has good head control and greatly increases room for the front seat.
How thick is the memory foam in the Radian RXT?
Hi Heather,
This is a great blog! I was hoping to get your opinion on the Diono R120 vs the RXT. I understand that the main difference is that the RXT has headwinds. I will likely buy a booster when the time comes, so the issue with the seat belt catching in the headwings is not important to me. However, I’ve read that many people have had the same issue you noted about the headings falling down. Is this not really annoying and uncomfortable for your child? Price is not an issue if the headwings are going to significantly improve the safety for my LO and I suppose that safety would also trump comfort. But I’m just stuck on the headwings falling down. Do you think they significantly improve the safety of the seat?
Thanks! Some details if important…the seat will be for my oldest daughter who is almost 3 and has just moved to FF in her First Years Truefit (my youngest will now use this). Since she will likely not want to switch back to RF, I will put her FF in the Diono.
Thanks Heather! I appreciate the info!
@Melis, the Olympia might work as a booster because the shoulder belt shouldn’t get caught in the belt guide. I’d want to check that the shoulder belt would touch the child’s chest, though–that it’s not held away by the sides of the carseat. Other combo seats to look at include the Graco Nautilus or Argos and Evenflo SecureKid.