CYBEX Sirona S vs. UPPAbaby Knox: Which is Better? (2024)

Hi there! We're here to help you decide between the CYBEX Sirona S and the UPPAbaby Knox.

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

Meet the CYBEX Sirona S and the UPPAbaby Knox, two premium convertible car seats designed with your child's safety, comfort, and growth in mind.

The CYBEX Sirona S makes a strong impression right out of the gate with its unique 360° swivel function, allowing you to easily place and retrieve your child from the car. This feature makes it a real game-changer for parents facing space constraints. Adding to that, the seat possesses SensorSafe technology, which delivers safety alerts right to your smartphone if ever a potentially dangerous situation arises. The Sirona S can accommodate children from 4 up to 65 pounds, with a maximum weight limit for rear-facing use up to 50 pounds, giving you more flexibility and longevity compared to many seats on the market. Although installation can be a bit complex and the overall size might be a bit bulky for smaller vehicles, the seat makes up for it through its high safety ratings, innovative features, and adjustable comfort settings.

On the other hand, the UPPAbaby Knox shines with its high-end aesthetics paired with safety features such as integrated Koroyd technology for absorbing crash impact forces, and one-button release chest clip that contributes to its ease of use. The seat can be used rear-facing up to 45 pounds and accommodates children forward-facing up to 65 pounds. While style and material quality are undeniably top-tier, the Knox falls somewhat short in terms of installation, as customers have reported challenges setting up the seat. Its larger footprint and heavier build also make it less suitable for smaller vehicles. One distinct advantage that the Knox holds over the Sirona S is its FAA approved modes for both rear-facing and forward-facing, making this seat a great option if you're a frequent flyer.

Upon comparison, the advanced features and maximized safety aspects of the CYBEX Sirona S give it an edge over the UPPAbaby Knox, despite the potential concerns with size and installation. The Sirona S accommodates a wider weight range, providing extended usability as your child grows, and the addition of unique features like the 360° swivel action and SensorSafe technology makes it a truly innovative choice.

However, if luxury aesthetics are priority and you have a spacious vehicle, the UPPAbaby Knox car seat presents itself as a robust and stylish option with high-end materials and appealing design. Furthermore, the FAA approval for both rear and forward-facing modes do make it a more travel-friendly option.

Overall, when considering safety, ease of use, and versatility, I would recommend the CYBEX Sirona S for parents who are looking for a long-term investment in a car seat that is packed with advanced features for convenience and peace of mind, and are willing to overcome the initial hurdle of complex installation. However, if travel-friendliness, aesthetics, and premium feel top your priority list, the UPPAbaby Knox would be your go-to choice.