The RadianRXT is designed to allow parents to restrain children as safely as possible for as long as possible. These seats can literally take children from infancy through childhood. A 3-in-1 design transforms this seat from a rear-facing seat with a 45-pound weight rating to a front-facing car seat with an 80-pound weight limit to a seatbelt positioning booster seat with a 120-pound weight limit. Maxing out at 57 inches, the RadianRXT exceeds Britax's highest height rating by 8 inches.
Because the RadianRXT is recent, it has not been independently crash tested; however, prior Diono seats earned scores of very good. Diono publishes its own crash test scores and measures on its website. The seats are able to maintain a narrow, 17-inch base because the frame is made with steel for greater underlying rigidity. The seat's side-impact protection is bolstered with aluminum rather than plastic, which reduces bulk without sacrificing strength. The RadianRXT offers side wing head protection to keep children's heads from moving in a crash and can be tethered and stabilized in the rear facing position.
The RadianRXT offers high-end convenience features like push-button connectors that anchor the seat to the car, but parents complain about a more challenging installation. The seat has a lower center of gravity overall and a relatively narrow path for the anchoring tethers and/or the seatbelt, which can make it difficult to route the straps and difficult to tighten them, particularly in the rear-facing position. There is a no re-thread harness height adjuster, but the harness tension is adjustable from the front. The cover is machine washable, but the harness has to be unthreaded to remove it.
The Radian RXT is our choice for best compact car seat because of its ability to fit three across, which is an important consideration under recent recommendations for how long children should be in a seat. Families may just find themselves with three children who are all young enough or small enough to be in a car seat at the same time. However, this seat's compactness is in width. The seat has a fairly high back which makes for a tight fit for rear-facing when fitting three across. It's important to take careful measurements to be sure it fits in your car.
The RadianRXT has soft foam padding that keeps kids comfortable and absorbs impact. But because the seats are relatively narrow, they don't offer the recliner-chair like arm rests other seats do. The seat comes with removable padding for better infant positioning.
The RadianRXT gets lots of attention for the fact that it folds for transport. However, with all that steel, it weighs a hefty 23 pounds, making carting it a back breaking experience in the words of more than one parent.
The Diono website is full of information and details about the safety of its line of car seats. Diono is marketing these seats as a long-term car seat solution for children, and the seats also boast an industry best usable lifespan of 10 years. Like most car seats, the RadianRXT carries a one year warranty. It also has an unusual crash exchange program. If you are in an accident with your child in the car seat, the company will send you a new seat in exchange for being able to examine the affected seat. There are limitations, and it's at the company's discretion.
It's an excellent compact seat for the long term, if the length works. While the RadianRXT is relatively new to the market place, it is already a top seller on most major retail websites and it has some of the highest user ratings. While parents tend to concur that installation is a bit harder, they don't turn away from the car seat on this basis. In fact, multiple users comment that they purchased more of these seats to accommodate other children, or that they will buy this seat again when they need another seat.
Our Sources: Diono Radian Car Seat Reviews
ConsumerReports.org included the Diono (Sunshine Kids) Radian XT SL in its round of convertible car seat evaluations. Because it is structurally very similar to the RadianRXT, the test results are still relevant. To read this report, you must be a ConsumerReports.org subscriber.
Review: Convertible Car Seat Overview, Ratings, and Recommended, Editors of ConsumerReports.org, May 2012
The RadianRXT receives a user rating of 4.5 out of 5 based on 67 reviews. Users love that they can fit three of these seats in the back seat. Users also comment on the tricky installation, but once the seats are installed, they say they were satisfied.
Review: Convertible Car Seats, Contributors to Amazon.com, As of Aug. 2012
Murphy describes the new features in Diono's new generation of convertible 3-in-1 car seats including the RadianRXT. This highly detailed review includes pictures of key details and a pros and cons list.
Review: Diono Radian RXT Convertible Review: A New Generation, Heather Murphy, Nov. 2, 2011