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!
Can you use the tether rearfacing? I have read a few places about this seat but I am seeing different answers.
I love reps who are as attached to their email as I am ;). Yes, you can use nonstandard spacing between 11″-14″. But remember not to share those anchors with another carseat.
Thanks. I’ll keep an eye on the thread. 🙂
Oops! I’ll check on it, Jenny. Probably won’t be until next week sometime, though.
Were you able to find an answer to Ketchup Queen’s answer? I have the same question for our 2002 MDX.
Will Diono recall or replace the belt guide for retract problem?
I have the Baby Trend Flex-Loc. BLEH! There are a lot of great things about this seat, but the puzzle buckle and constantly twisting straps ruin it all! Looking for a hassle free convertible but also something that doesn’t take up the entire backseat of my RX as we have two adults back there fairly often. I’m not too worried about harness adjuster, etc. If it’s difficult but only has to be done every few months, that’s fine. But I don’t want to be fighting my car seat on the daily things. So if you think the new Radians are a lot easier to install, I’m all for them! Any other car seat suggestions?
Am wondering if you could tell me what the top harness height is? we are hoping to make a 3 across in a cr-v with 2 rfing xtsls and 1 rxt ffing but the oldest is not heavy enough for booster mode so i’m hoping the harness is a bit taller. My ‘small’ 6 year old outgrew the xtsl shortly after she turned 6.
@Katelyn, I installed it on the passenger side outboard in our RX330 and it installed pretty easily. When I tried the Radian 80 way back when, it was much more difficult forward-facing. I also put it behind the driver then, so it may have to do with seating position (and your back seat is probably a bit different than mine). When I read comments about the Radians, the most common one I see is against the harness adjuster. I didn’t have problems with the one on my seat either rf with a doll or ff with my dd, but it’s definitely not smooth as silk like Britax seats or the Chicco KeyFit. What infant seat do you have?
I have an RX300 and am so curious what you thought about installation in that car? It’s already a tight fit with our infant seat in the middle with two adults sitting on either side which is why I’m drawn to the Radian (that and the high rear-facing weight limit.) But I am so worried about the drawbacks. I really need an easy seat to use as I am impatient and seriously hate the infant seat we have now. I do not want another annoying car seat. For the RX, what seat do you use? Is there one that is good for rear-facing, taller children but also doesn’t take up the entire back seat and is easy to use?
@Wendy, yes, the SafeStop is only used forward-facing for installs using the tether when the child is 20-40 lbs.
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KQ, I don’t know. The manual for the RXT has the same wording as the old XT manual: “Confirm vehicle seating location has its own LATCH anchors (see vehicle owner’s manual). If it does not, you must use vehicle seat belt . . .” I’ll check on it.
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@Leigh, yes, it does LATCH in booster mode. But it’s not required.
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@Katie, my skinny dd hit 50 lbs. somewhere after age 7, so I know what you mean about the min. booster weight limit. I would imagine that Diono probably feels that it’s safer to harness children as long as they still fit properly in the seat, which is why they put the limits on it that they did.
I refused to get a Radian XTSL because of the potential RFing installation issues but once the Angle Adjuster is available I would seriously consider an RXT. We have our 15 month old in a pair of Britax Boulevard 70s which we all love. However, she has a long torso, a big head, and is a lightweight, so an RXT with the angle adjuster may be in our future to keep her RFing longer than the Boulevard will allow.
I am a bit disappointed that the booster minimum is 50 lbs. If our toddler stays on the percentile she’s been on consistently since birth, she will be 7-8 years old by the time she hits 50 lbs. We would like to start booster training earlier than that so would not be able to use the RXT in booster mode (and by school age I will take the child’s preference into account if she wishes to be boostered safely rather than harnessed!). A 40 lb booster minimum would be more of a selling point for me as a parent, but as a harnessed seat it looks pretty sweet.
Does it LATCH in booster mode? It seems awfully heavy for a booster.
Wow, thanks for this thorough review, Heather. If I didn’t already have eight convertibles (including three older Radians), I might even consider getting one. 😉
Diono is going back to not allowing non-standard LATCH spacing, is that what you’re saying? Because as Sunshine Kids, they first said no, then changed it to yes, between a certain distance, now they’re going back to no?
You don’t use the Safe Stop between 20 and 40 pounds rear facing, do you?
And, the R100 rear faces to 40 pounds according to Diono’s site, not 45.
Wendy
“… [S]ince everyone knows to tether all the time, you essentially use the SafeStop when the child is between 20-40 lbs.” If you are fortunate enough to have vehicles new enough to have tethers, fine. Not everyone does. I have one vehicle with tethers, and one vehicle that does not have them and is not retrofittable.
I am sad to hear about the issues in booster mode. I guess you can’t do everything right….
@Brigala, that 16.5″ measurement is at the widest point in the thigh area (seat) with the armrests extended out; it’s as wide as it gets there. I measured it at 14.75″ with the armrests up.
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@NicoleCPST, yes, it can be LATCHed while in booster mode.
Any word on use of LATCH when using it in booster mode?
Next question: Your outside dimensions measure 16.5″ across the thighs. The previous Radian is normally quoted at 14″ but I’m not sure exactly where that measurement is taken. Is the new Radian any wider and/or different in its outside dimensions compared to the old one? I need to know because I was going to sell my unused Radian and get a new one later if/when I need it. But if the new one is any wider, I’d better hold on to it or I’ll need another car if I have any more kids!
Thank goodness!! 🙂
@D, it’s hard to tell how much room it takes front to back because it depends on the vehicle seat cushion incline: a carseat installs more upright on a cushion that has more incline. The Radians are tall seats and will take a lot of room when rf.
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@Brigala, OOPS! That slipped in somehow, but I corrected it in the review. Rf tethering is allowed with the Radians.
Wait, what?
“The tether strap is to be used forward-facing only.”
Did I hear you correctly? The new Radians don’t allow rear-facing tethering??
That has to be a mistake? Or did I misunderstand something?
I love the purple! In RF mode, how much room does it take up with regard to depth? We’re in the market for our 2yo, but I have serious doubts about it fitting in our Honda Fit rear-facing without having to pull our front seats too far forward. That recline looks like it takes up a fair amount of real estate.