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!
I’m wondering the proper way to measure the amount of space left between the top of the seat and the child’s head. Since the top has a curve to it, I’m not sure I’m getting an accurate measurement. My son his 40″ but has a long torso.
@Alice, are you looking for a carseat that’s narrow side to side or small front to back? I’m guessing a little bit of both since the Rio is a small car. The Radian is definitely a narrow seat, but it takes up a lot of real estate front to back because it’s so tall. If your 3rd child is close to age 1 and has good head control, you can use it with the angle adjuster accessory to get more room up front. Otherwise you might want to look for either a shorter seat or one that works better angle-wise, such as the Graco Size 4 Me/Head Wise/My Size, or the Peg Perego Convertible. A trick you can use so that your 5 yr old doesn’t accidentally unbuckle the carseat buckle is to give the carseat buckle a half-twist so the red button is facing in if you’re using the vehicle seatbelt to install it.
Also, glad to see 5 yr old is still in a booster! Have you read Kecia’s blog on the 5-step test? https://carseatblog.com/3966/the-5-step-test/
Hi, I am looking into getting a convertible car seat for my 3rd baby. She is currently in a chicco key fit 30. We drive a 2008 KIA Rio and the chicco is a snug fit so we are looking for something the same size or (preferably smaller) as my 5 year old is still in a booster seat. What kind of seat do you suggest for us?? Thank you for your help
We have a Sunshine Kids Radian XRT that my 2.5 yo currently uses RF. She’s lightweight at only 24 lbs. We are expecting baby #2 and are shopping for carseats. I’d like to buy a convertible so that we’re only making one purchase that will last us a long time. We’re deciding between the new Diono Radian XRT model, or something like the Britax Advocate 70-G3 for the side impact protection. Any advice about how either of these seats will fit a newborn?
@cambria, I believe they’ll fit, but I don’t know if they’ll give you the legroom you need–I’ve never worked in a Suburban so I don’t know how much space there is. Diono does have an angle adjuster that makes the seat more upright, but they recommend its use after age 1. You can call and ask their customer service line about it. Another seat to consider that is very comparable to the RXT is the Peg Perego Convertible: https://carseatblog.com/16793/peg-perego-primo-viaggio-sip-5-70-convertible-review/ . You can put the Peg more upright straight off without having to wait until age 1.
I have twin girls who are just about 8 months and I’m going back and forth on bigger carseats for them. I love the features of the RXT, but I’m curious if you have any idea if it will fit rear facing behind the driver side of a 2006 Chevy Suburban? My husband and I are both about 5′ 9″, but I have long legs. One of the twins will have to be behind the driver and the other twin in the middle, every seat in our suburban is full! LOL! I’m loving the idea of this seat as I won’t have to buy another car seat after this! Thanks for your input!
@Rebekah, it means that once the child is turned forward, only the top 3 sets of slots can be used forward-facing. You can use any slots rear-facing as long as they are at or below the child’s shoulders.
I recently bought an RXT for my daughter, and I am confused about one thing in the manual. It says, “ONLY use top three shoulder harness positions for forward-facing child.” Does this mean that the top three positions should only be used for a forward-facing child (as in, not allowed for use rear-facing), or once a child is forward-facing that only the top three slots should be used?
Accessing the infant head support pillow was more difficult and laborious than child birth. Why didn’t they just include the infant head rest in the massive box it came in?!
@Kathryn. How old is your child? How well it fits front to back depends on whether or not you’re able to use the angle adjuster foam wedge under it. It doesn’t have the deepest sides of the carseats out there, but that’s what allows it to fold. I think people forget that it started off as a travel seat, lol, then it became this awesome rf-forever seat. But rf carseats offer a lot of protection, even in side impacts. I don’t know a lot about the Euro, but the Recaro convertibles tend to be hard to use in smaller cars because they sit so high up on their bases; it’s hard to get the kiddos in the seats.
Me again! If the Radian is not the best for side impact protection, I’m wondering what carseat you might recommend that would fit our Civic well? Any thoughts on the Recaro Euro?
Thanks!
Hi! We are looking for a good convertible that will fit in our 1998 Honda Civic. We take a lot of long road trips, so it’s important that the front passenger seat has some leg room. Do you know if the Radian will fit well, RF? I’m also concerned about the side impact protection. Just eyeballing the Radian in comparison to other carseats, it looks like there are no sides!
Thanks!
Thanks so much Heather 🙂 That helps!
@marivi, it should fit a newborn well and I know many folks use it for their newborns. It’s got a great recline angle for a noob and with the padding included with the seat, fit should be OK.
Does this seat fit newborns well? I bought it for my DS when he was 8 months old, and love it. Want to skip the bucket seat and just buy one Diono that will last forever for new baby on the way, but want to make sure it will fit a newborn. My son was 6lbs 14oz at birth. I assume this next one will be a similar size.
Ok, I thought this seat was a great idea to allow more space in the back seat, but I HATE my Diono Radian! It is so difficult to get the seat cover off for cleaning, I want to throw it into the street when I am struggling to get the cover off to clean pee/poo/vomit. Such a fun job already, and this seat makes it infuriating torture! I would not recommend this seat.
@Beth, glad it’s working for you now!
Hi there, I finally got my seat installed with the angle adjuster tethered, and it feels solid as rock! It fits well rear facing in my 08 Honda CR-V behind the drivers seat, with a reasonable amt of room for me to be comfortable. I am 5’7″ with long legs for anyone out there wondering if this seat will fit in your car. Thanks so much for your help. I have used your site and reviews so many times while choosing a car seat!
Thank you Snowbird! Im sorry i havent been back in a while. I FINALLY registered with carseat org and posted pics of the uas strap adjuster slipping too far into the belt path. :/ I hope that makes sense. And yes, I did remove the damaged UAS and used seatbelt install. I have since gotten a replacement uas from diono, but there are pics of the new one on the carseat.org site… I fear that it might still be sitting too far into the belt path, on too much of a corner. Anyways, thanks a million for your help and I hope to hear back on the photos soon 🙂
Thanks so much! Great info! I didn’t have it tethered yet, and I will use the link you sent. From what I have read I also think that rear facing is the most important thing, and it is the RXT with head wings.
@psmama, I don’t know how I missed your comment–so sorry! The Radian will probably be a tight squeeze in your TSX, but you could try it with the angle adjuster. Diono recommends using the angle adjuster after age 1, but if your bub has good head control and doesn’t sleep much in that car, you could make a parental decision to try it out. Or scrap the use of the passenger seat and move it all the way up ;). The Silverado shouldn’t be a problem. I’m surprised to hear he’s outgrowing the SnugRide 35 already! He must have a tall torso! That seat is outgrown when the weight limit is reached or when his head reaches within an inch of the top of the seat shell.
@Beth, the install should be just as secure with the angle adjuster as without. When you tug at the belt path, it should move less than 1″. It will move a lot up by the head because there’s nothing holding the carseat there. BUT, the Radian can be tethered when it’s rear-facing, so the head portion can be secured. Find a point on your front seat track and wrap the d-ring around it, then attach the tether. Here are the specifics: https://carseatblog.com/12749/how-to-use-a-rear-facing-tether/ . As for being on the side and how much side impact protection the Radian has, it doesn’t have much in the torso area for sure. That’s why I like the RXT–because it has those head wings. In a side impact, the back of a rear-facing seat will turn slightly toward the impact so the child is protected. That’s why it’s so important to rf for as long as possible which is what I think is more important than the brand of carseat.
Hello! You did a great review on this seat! I just received it in the mail and I purchased it so we could keep our son rear facing for as long as possible (he is in the 95th percentile for height, and at 1 shoulder height is 13 inches). I installed it behind the driver seat, and I am going to have to use the angle adjuster. I am just a little concerned because the seat seems a little wobbly,and I am not sure how stable the seat really is with the foam wedge. My son just turned 1 on September 20 th so I am not sure if that is to soon to use the angle adjuster. I am starting to think that I should have gone with the Britax,and now that I have him side boarding I feel like maybe he needs deeper side walls. Thoughts????
Hello! Great review. I’m considering the Radian RXT for my 10 1/2 month old son, ~25lbs and ~30″. He has just about outgrown his SnugRide 35. I like the fact that this seat can accomdate taller children, sits lower on the seat, keeps them rear facing longer and is not as wide as some of the other convertible seats. Do you know if it will fit in a 2007 Acura TSX and a 2002 Chevy Silverado (rear-facing)? My other concern is the side impact protection. It does not seam as deep as other models but from the comments above, it seems like it has to do more with protecting the head? Providing it fits in our cars, is this the best option for tall children (especially rear-facing option) or is there another seat that I should also consider? Thanks in advance!
@blessed, I believe you can. Is there a way you can find a store nearby to try one out? If not and you’re buying online, be sure you can return them easily.
Both Rear facing I must clarify! 🙂