CYBEX Sirona S vs. Diono Radian 3R: Which is Better? (2024)

Hi there! We're here to help you decide between the CYBEX Sirona S and the Diono Radian 3R.

Our goal is to provide you with the information you need to feel confident that you're choosing the optimal car seat for your family's needs and budget. Let us know if you have any other questions!

At A Glance

Our Thoughts

As a parent, car seat safety is undoubtedly a top concern. Right now, we're comparing two popular products on the market. On one hand, we have the CYBEX Sirona S - a versatile convertible car seat loved for its 360° swivel feature and enhanced safety technology. On the other hand, the Diono Radian 3R, with its slim design and steel frame construction, offers multiple seating options and a space-saving design.

The Cybex Sirona S is a convertible car seat designed for both rear and forward-facing use, accommodating children up to 65 pounds in the forward-facing position. It shines with its SensorSafe technology that alerts parents to potential unsafe situations. Its innovative 360° swivel design adds a layer of convenience—especially helpful for parents with troublesome back issues or confined parking situations. However, the increased complexity of the design does cause some parents to find the installation process challenging. The cover is also removable and machine washable, simplifying the cleaning process. The Cybex Sirona S is a bit bulky and might be a tight fit for petite vehicles, but the overall benefits in terms of safety and convenience make it a high-value choice for growing families.

In contrast, the Diono Radian 3R stands out for its slim design, permitting three-across seating in most vehicles. This is a major advantage for families with multiple children who still want to maximize backseat space. The Diono Radian 3R offers an impressive array of seating configurations: rear-facing up to 40 pounds, forward-facing up to 65 pounds, and even as a high-back booster up to 100 pounds. However, it should be noted that some parents expressed concerns about the lack of head support which becomes increasingly significant in booster mode. Additionally, while the seat cover is removable, some parents reported challenges in its maintenance and durability. Furthermore, the Radian 3R is also remarkably heavy, complicating its use for frequent vehicle swapping.

Considering these aspects, if superior safety is your main preference and your budget allows for it, the CYBEX Sirona S could be an exceptional fit for you, offering advanced safety features such as side-impact protection, SensorSafe technology, and a versatile swivel function for comfort and accessibility. However, if your top priority is outfitting a smaller vehicle with multiple seats, the slim yet robust Diono Radian 3R, with its long lifespan and diverse seating modes might be the better option. Overall, both seats present unique advantages depending on specific needs.