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!
@Mary, the strap that connects the LATCH strap to the carseat just kinda hangs there. You can try to tuck it away, but really, every seat has it.
Received my new rxt in the mail and want to try to install it but I can’t seem to figure out what to do with the strap that the latch connectors routes through. It seems to make sense how the to route the latch straps through the rear facing belt path, but there is the strap off to the side that just kinda hangs there. It just looks weird and I dont see it in any of the picture or the video of the installed car seat. Help?
@Bonnie, it should be compatible. How are you testing for movement? You should only grasp the seat at the belt path with your non-dominant hand and give a tug. Even on the most tightly installed seats, if I really try hard to shake them loose, I can.
I just bought a new Diono RXT and tried to install it RF’ing in the second row bench, middle seat, using the lap seat belt of my 2002 Ford Excursion. The attached “foot” on the bottom front of the RXT seems to slide to far down into the crack (opening between the back of the trucks seat & the sitting bottom part of the trucks seat). Do you know if it is s’pose to be compatible as I described trying to install it? Also, we got the seat belt extremely tight (holding the RXT onto seat) and were still able to slide the RXT a good inch or more from side to side along the seat belt. Any suggestions? Thank you 🙂
@andream, Diono says it’s fine to NOT use the shoulder belt guides if they cause the belt to get caught in them. Parents should check for proper belt fit over the center of the child’s collarbone (or a bit closer to the neck) if the belt guides aren’t used.
Someone asked above if Diono will recall or replace the belt guide for retract problem. I didn’t see an answer and was wondering if you’d received one. If the belt guide doesn’t allow the belt to retract properly, then the seat essentially isn’t safe in booster mode and in general the seat loses some of its allure as a 3-in-1. Any info you can provide would be great!
Thanks for the review. I needed to replace all three car seats for my boys (5,3&18 months) I had a britax regent and two boulevards before but got three radian RXT. At the store I liked that they were narrow and can fit three next to each other in my van. We have baby 4 arriving soon and really wanted seats for the boys that would provide the most space in the van.
@Mandy, the only Diono Radian with headwings is the RXT. The R100 doesn’t have the memory foam in the seat pan area, but it still shouldn’t be entirely uncomfortable because there is padding built into the cover. I’ve never heard of any kids complaining about the cushioning.
What a great review. We are trying to decide btw the RXT and the R100 for our 40+lb almost 4 year old son. Our 7 mo 19 lb daughter will use his safety 1st seat. He will use the radian for abt 3 yrs and then we would like to pass it along to our daughter. We don’t need the infant cushion feature. Is there any head support on the R100 or is the protection for the head only found in the RXT? Also, would the seat be uncomfortable on the R100? Many thanks in advance, Mandy
@coasting anon, I remember the cup being tough to stick into its spot on the seat and it won’t fold with it in. Try brute force to yank it out, lol. There are fabric loops on the bottom back corners and the middle of the back of the seat for attaching the carry straps.
@joy, I was told that for the RXT, it’s ok to adjust the headwings to where I need them, then carefully tighten the bolts on the back. Careful not to over tighten! Give Diono a call to double-check that this is ok to do.
Hi, I have a Radian 80 xtsl and I love the width of it. But I was taking off the cover to clean it the other day and I noticed that the side impact headrests (the wings) were way down low. I adjusted them back up but there is nothing to lock them into place. Gravity just pushes them back down again. This means that they sort of sit on my son’s shoulders. Is this normal? Is this issue fixed in the newer Diono seats?
Oh I am SO hoping you can answer this quickly as we are headed out of town in four days!! I just got the Diono RXT for my 2.8 year old who’s the size of a four year old. So far we really love it if for no other reason than he can actually get himself IN the carseat by himself – the Britax Boulevard and Frontier we had prior to this were too high for him to climb up into.
I have two questions – 1) we installed the cup holder but I can’t seem to get it out. Can you fold the seat with the cup holder attached? Should I be able to get the cup holder out if I pull hard enough?
2) I can not for the life of me figure out where to attach the two shoulder straps that I purchased to be able to carry it like a back pack. Any chance you can post a close up of that picture?
Thanks so much!!
Thanks for your patience! It’s been a busy week!
@Steph, the Diono Radian seats are the narrowest, but the new Peg Perego convertible is fairly narrow too. The Cosco Scenera is also a narrow seat, but it lacks the features the other two have plus only has a 40 lbs. maximum ff weight limit.
@Amber, I think the same applies to you. I’d put the 3 yr old in a Radian (at 3, a child should still be harnessed).
@Hope, I did a quick search at car-seat.org and it looks like the Radian might be trouble in a Mini Cooper. The Britax convertibles and the Learning Curve TrueFit seem to fit well. In the Jetta, the Radian should work, especially with the Angle Adjuster to put it more upright.
I have an 02′ Nissan Altima. I have 3 children, currently my 5 and 3 year old are in britax parkways. which are 17 inches wide. My 3 month old is in a Graco 30 which is also 16.5 inches wide. Its very tight in my back seat. Was wondering if this was the skinniest rear facing car seat you had?? And also can i use the latch belt system while rear facing??
What a great review!
My husband and I are trying to fine a new carseat for our 2 year 3 month old. She is outgrowing (in height) her Combi Cocorro. We drive a Jetta Sporstwagon and a MINI Cooper Countryman. We’d like to keep her RFing for as long as possible. Any idea how this seat would fit in either of those cars?? I saw a photo with a RF Cocorro next to another RF seat, which I’m assuming is the Diono, so I’m wondering if it might fit??
Any thoughts would be helpful!
Hope
I have an 02′ Nissan Altima. I have 3 children, currently my 5 and 3 year old are in britax parkways. which are 17 inches wide. My 3 month old is in a Graco 30 which is also 16.5 inches wide. Its very tight in my back seat. Was wondering if this was the skinniest rear facing car seat you had?? And also can i use the latch belt system while rear facing??
Thank you for your advice! If you know of another seat that would compare to the Diono RXT please let me know. I’m a 1st time mom and I just want to get the right seat for my LO and to fit properly in our SUV, Thanks again
@Joy, Sunshine Kids fixed the LATCH adjuster in about Feb. ’11. So if your seat is older than that, give Diono a call and they should ship you a newer LATCH strap to use.
@Steph, from what I’ve seen, the Radian should work well in the 2nd row outboard positions. Whichever carseat you buy, make sure it fits with less than 1″ of movement at the belt path and that you can adjust your child in the seat easily.
I’m trying to figure out what is the best convertable carseat to purchase for my LO, she will be 17 mo on Mon 3/19, at her 15 mo well visit she weighed 25 lbs & 32.5 in, we want to RF as long as possible, we have a 2006 GMC Yukon Denali XL, I’m interested in the Diono.
Hi there! We’ve had the Sunshine Kids Rxt for about 1 1/2 yrs. One day I was SHOCKED to find the latch belts were extremely loose. After some research, I found that this had been a problem for others too. Do you know if the problem seems to continue for the new Diono ones? I really like a lot of aspecs of our Sunshine Kids one, and am hoping to buy a new Diono for our newest toddler too.
Thanks @Heather. I have a couple more questions. Other than the still {expensive} vapourware Foonf from Magna, do any other NA convertible car seats have the rigid ISOFIX connectors? Also, are any of them able to use a rigid front brace (as opposed to the top tether) when rear facing?
@Verb, I found these 2 threads for you. http://www.car-seat.org/showthread.php?t=168158 and http://www.car-seat.org/showthread.php?t=210700 It looks like in the Mazda 3, it’ll be a very tight fit without the angle adjuster. @Natty, the Radian seats actually have some of the most leg room of convertible seats. It’s a thin seat, so there’s plenty of room for the child’s legs. It has more leg room than the Britax convertible seats. But keep in mind that kids fold up their legs and are comfortable that way.
Given the Diono Radian seats do not have much of a base how is the leg room rear-facing?
I understand there is a base attachment to tilt the seat to the appropriate (~45) angle for smaller infants … and foam angle-adjuster to right the seat back to a 25-30 degree angle, but what is the available leg room in both these positions?
You might expect the leg room to decrease as the seat is positioned more vertical? Given the weight limit, we would like to keep out little guy rear-facing until he is 4-5, but he’s long legged (not sure where he gets it, but flood pants have been his style since he arrived).
I’m trying to get a feel for how the Radian would compare to {say} a Britax Boulevard – which we tested, but found it took too much real estate – or the new Magna/Clek Foonf {whose specs are intriguing, but price is more than my first car} ?
This seat is tempting, but I’m worried about the RF fit in my husband’s 2005 Mazda 3, with another child riding in a Frontier passenger’s side. Our child is under 1, so it would be a while before we could use that angle adjuster.
@Alysha, yes, the Radians can be tethered rear-facing.