In Depth Baby Product Reviews Led by a Pediatrician

Cybex Sirona M with SensorSafe 2.0 Review

Pricey car seat that looks good but fails to offer an additional margin of safety
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cybex sirona m with sensorsafe 2.0 convertible car seat review
Credit: Abriah Wofford
Price:  $450 List
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Manufacturer:   Cybex
By Juliet Spurrier, MD and Wendy Schmitz  ⋅  Dec 21, 2021
62
OVERALL
SCORE


RANKED
#17 of 17
  • Crash Test - 35% 4.0
  • Ease Of Install - LATCH - 20% 7.6
  • Ease Of Install - Belt - 15% 7.5
  • Ease Of Use - 15% 7.5
  • Comfort / Quality - 10% 8.4
  • Weight / Size - 5% 4.5

The Skinny

The Cybex Sirona M with SensorSafe 2.0 is an interesting convertible car seat with some unique features. This seat is easy to use and installs equally well with LATCH and the vehicle belt, sporting a unique LATCH connector that removes easier than anything we've ever seen. It has the SensorSafe technology, which is intriguing, but we aren't convinced it is enough to make up for the higher price of the Cybex or the disappointing crash test results. While we do like the way this seat looks and the comfort value is high, we think there are better seats that offer an additional margin of protection that you will love for a lower price, like the Britax Emblem.
REASONS TO BUY
Easy to install
Nice quality
No-rethread height adjustment
REASONS TO AVOID
Disappointing crash tests
Price
Wider
Harder to carry
Editor's Note: This gear review was updated with more details to compare products and help the reader make a decision on which seat to buy. The update occurred on December 21, 2021.

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Awards  Top Pick Award Top Pick Award Editors' Choice Award Best Value Award 
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$349.99 at Amazon
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Bottom Line Easy to install and use, quality seat but the price and crash test results are lackingParents will love this easy to install, quality seat with nice featuresQuality seat with comfy features and great crash test results, but a high priceRear-facing up to 50 lbs and the best crash results are a bonus to this budget-friendly seatGreat lightweight seat with excellent crash test results that is very easy to use
Rating Categories Cybex Sirona M with... Britax Boulevard Cl... Nuna RAVA Graco Extend2Fit Britax Emblem
Crash Test (35%)
4.0
5.5
7.5
8.5
8.0
Ease Of Install - LATCH (20%)
7.6
9.5
7.7
6.6
7.2
Ease Of Install - Belt (15%)
7.5
9.6
8.2
7.0
6.0
Ease Of Use (15%)
7.5
7.6
6.6
7.3
7.6
Comfort / Quality (10%)
8.4
8.6
8.8
5.8
7.4
Weight / Size (5%)
4.5
5.0
4.0
5.0
5.5
Specs Cybex Sirona M with... Britax Boulevard Cl... Nuna RAVA Graco Extend2Fit Britax Emblem
Crash Test HIC Score 409 289 292 214 218
Crash Test Chest G Clip 49 51 40 40 42
Min/Max Rear Facing Passenger Weight 5 - 40 lbs 5 - 40 lbs 5 - 50 lbs 4 - 50 lbs 5 - 40 lbs
Min/Max Forward Facing Passenger Weight 22 - 65 lbs 20 - 65 lbs 25 - 65 lbs 22 - 64 lbs 20 - 65 lbs
Max Rear Facing Passenger Height Child's head must be at least 1 in. below the top of the head restraint Child's head must be at least 1 in. below the top of the head restraint Not Listed Child's head must be at least 1 in. below the top of the head restraint Child's head must be at least 1 in. below the top of the head restraint
Max Forward Facing Passenger Height 49" 49" and the child's ears must be below the top of the head restraint. 49" 49" and the child's ears must be below the top of the seat shell. 49" and the child's ears must be below the top of the head restraint.
Measured Rear Facing Seat Weight 23.8 lbs 29.5 lbs 25.8 lbs 18.7 lbs 18.8 lbs
Measured Forward Facing Seat Weight 23.3 lbs 28.4 lbs 25.4 lbs 18.7 lbs 18.8 lbs
Width 19.6" 18" 19" 19.6" 18.9"
Recline Positions 1-6 Rear Facing
5-10 Forward Facing
7 5 Rear Facing
5 Forward Facing
4 Rear Facing
3 Forward Facing
1 Rear Facing
2 Forward Facing
Max Recline Angle 49° 51° 40° 51° 42°
Shoulder Harness Positions 12 14 10 10 10
Crotch Strap Positions 3 2 2 2 2
Built in Lock Off Yes ClickTight System True Tension Door No Yes
Anti-rebound Device No Yes No No No
Head Support Yes Yes Yes No No
Newborn Insert Yes Yes Yes Yes Yes
No Rethread Harness Yes Yes Yes Yes Yes
Onboard Manual Storage Yes Yes Yes Yes Yes
Level Indicator On Seat Ball in Tube. Ball in Tube. Indicator on base Ball in Tube. Line on Decal
Foam Type EPS EPP EPS EPS EPP
Seat Lifespan 8 yrs yrs 10 yrs 10 yrs 7 yrs 7
Warranty 2 Years 1 Year 1 Year 1 Year 1 Year

Our Analysis and Test Results

Cybex is a German company that is now part of Goodbaby International Holdings Ltd. Cybex focuses on creating functional products with an eye on safety and design. They currently make car seats, carriers, and strollers.

Performance Comparison



cybex sirona m with sensorsafe 2.0 convertible car seat review - the adjustable headrest/harness assembly contains eps foam for...
The adjustable headrest/harness assembly contains EPS foam for impact absorption.
Credit: Abriah Wofford

Crash Test


The Sirona didn't perform well in our crash testing compared to the competition. While it offers a basic level of protection like all car sets for sale in the US and meets the federal guidelines, it didn't perform as well as the competition. While it did not have the worst sensor results in the group, it did have results below the average.

The chest sensor result for the Cybex was 49, where 60 is the maximum allowed, and a lower number is better. The average for the group is 44, while the best result is only 33 earned by the Clek Foonf.

cybex sirona m with sensorsafe 2.0 convertible car seat review - this chart shows a comparison between the crash sensor on the head...
This chart shows a comparison between the crash sensor on the head between the Britax Allegiance (green) and the Cybex (black). It is easy to see that the Cybex experienced more than twice the amount of Gs as the Allegiance. A lower number is desirable.
Credit: BabyGearLab Staff, MGA Research
cybex sirona m with sensorsafe 2.0 convertible car seat review - this chart shows a comparison between the best chest sensor result...
This chart shows a comparison between the best chest sensor result from the Foonf (in green) and the Cybex (in black). The Cybex has a result of 49 compared to the Cleck's 33 Gs. A lower number is better.
Credit: BabyGearLab Staff, MGA Research

For the head sensor (HIC), the Cybex sensor result was 409, where 1000 is the maximum allowed, and a lower number is better. The low (best) result for the group was earned by the Britax Allegiance with a stunning 186 g result. The average for our group is 351.

These results indicate that Cybex struggles to compare to the competition when analyzing the crash test results.

cybex sirona m with sensorsafe 2.0 convertible car seat review - the "linear side-impact protection" on the cybex is a nice to see...
The "linear side-impact protection" on the Cybex is a nice to see feature but its true efficacy is difficult to determine without more information on the testing of this feature and how the 25% claim was assessed.
Credit: Abriah Wofford

The Cybex also features what they call linear side-impact protection that they claim absorbs up to 25% more impact forces than seats without this feature. While we love all things safety, it is hard to determine the truth of the claim or how it was tested without transparency from Cybex. We could not find any information on how the seat was tested or how the efficacy was determined.

cybex sirona m with sensorsafe 2.0 convertible car seat review - the chest clip on the cybex has the sensorsafe technology that...
The chest clip on the Cybex has the SensorSafe technology that transmits information to the port on your car and your smartphone.
Credit: Abriah Wofford

The Cybex also sports the "SensorSafe" technology that detects when little ones have slipped out of the shoulder portions of the harness, and it sends this information to your phone. We aren't sure how often this problem occurs in real life, as a well-fitted harness should not allow a child to slip out, and a well-designed clip should be relatively childproof and hard enough to open that a child can't manage it. However, it also monitors other things that could be very useful. This feature relays if the temperature in the car is too high or too low and if your child has been sitting in the seat for an extended period of time. When you reach your destination, the technology will remind you that your child is still buckled in the back seat. It will then notify your designated emergency contacts of your location if you do not remove the child from the seat. These alerts are designed to help prevent parents from accidentally leaving their child in an unsafe car and could theoretically help prevent unnecessary death from things like overheating in a hot car. This feature works with your smartphone and does emit Electromagnetic Frequency (EMF), so you need to determine if the feature aligns with your goals and the EMF level is considered acceptable for the benefits you gain. This feature will only work on late model cars with a port for installing the receiver port that comes with the seat.

Installing the Cybex in a forward-facing position requires the use...
Installing the Cybex in a forward-facing position requires the use of the tether strap and allows you to use the door side of the seat linear side-impact feature.
Installing the Cybex with the vehicle seat is simple with a...
Installing the Cybex with the vehicle seat is simple with a well-placed, easy to use lock-off.

Ease of Install - LATCH


The Sirona LATCH installation is a smooth operation for ease of installation using the LATCH. This LATCH system is not that straightforward, and until you figure out that you need to slip the tails of each strap through the slots on the seat to tighten, it can feel near impossible to tighten well. You need to ensure that the strap is positioned properly over the "hump" in the seat, but once it is, it is easy to use and can get as tight as you need it. While some testers wished this step wasn't necessary, it isn't difficult, making tightening a breeze.

The LATCH connector on the Cybex is unique in design which makes it...
The LATCH connector on the Cybex is unique in design which makes it easier to attach and release than other connector styles we've seen in the past.
The Cybex has a unique LATCH connector that has a push in connection...
The Cybex has a unique LATCH connector that has a push in connection with a cool pull to release strap.

The LATCH connectors are somewhat unique and easier to use because the shape allows you to press the back end with your thumb to push into place (above left). There is also a pull tab to release the connectors (above right) that are far easier to use than the traditional button.

The rear-facing belt path for the Cybex is near the foot of the seat...
The rear-facing belt path for the Cybex is near the foot of the seat and can be accessed without removing the padding or cover.
The Cybex forward-facing installation has an easy to access belt...
The Cybex forward-facing installation has an easy to access belt pathway that doesn't require moving the padding or cover.

Ease of Install - Belt


The Sirona is equally as easy to install using the vehicle belt, earning the same score as the LATCH installation.

The vehicle belt slides into the Cybex lock-off to hold the strap in...
The vehicle belt slides into the Cybex lock-off to hold the strap in place. The belt can be tightened without releasing until you want it to be.
The Cybex has labeled lock-offs that instruct the user on where to...
The Cybex has labeled lock-offs that instruct the user on where to put the belt so there is less room for error.

The belt lock-off for forward (above left) and rear-facing (above right) installation are both difficult to see, making threading the belt more challenging. However, once you get the belt through, it is easy to tighten and use the lock-off to hold the strap in place. The lock-off allows the strap to tighten but not loosen. Rear-facing is more difficult because the lock-off allows the strap to fold and wrinkle.

The angle of the Cybex is adjustable by using the lever on the foot...
The angle of the Cybex is adjustable by using the lever on the foot of the seat to move the seat for comfort or proper installation.
The level on the Cybex is a metal ball in a plastic casing. The ball...
The level on the Cybex is a metal ball in a plastic casing. The ball moves smoothly for an accurate reading.

The Sirona angle can be adjusted (above left), and the level indicator (above right) has a range to help ensure the right angle is used. Both features work well and function as expected.

cybex sirona m with sensorsafe 2.0 convertible car seat review - the harness tightening strap works smoothly and easily but the...
The harness tightening strap works smoothly and easily but the release button is positioned fairly deep inside the seat under a plastic cover designed to limit child access.
Credit: Abriah Wofford

Ease of Use


The Cybex is easy to use with features that function as they should.

cybex sirona m with sensorsafe 2.0 convertible car seat review - the harness height on the cybex can be adjusted on the fly with your...
The harness height on the Cybex can be adjusted on the fly with your child in the seat by squeezing the lever and moving the assembly up and down as needed.
Credit: Abriah Wofford

Harness


The harness on the Cybex has a non-rethread height adjustment you can move with a child in the seat. It is easy to use and moves smoothly up and down when you squeeze the lever. The harness has 12 height positions, and the crotch strap has 3 providing enough variation to fit most children well.

cybex sirona m with sensorsafe 2.0 convertible car seat review - the buckle on the cybex pops open on its own so you don't need to...
The buckle on the Cybex pops open on its own so you don't need to remove the parts.
Credit: Abriah Wofford

The buckle on the harness is a little stiff, but it pops open, and the parts move out independently. The chest clip feels like it gets a little hung up on the rubber back, but it releases easily. The tightening strap moves smoothly, and the release button is sort of deep within the foot of the seat with a plastic cover that prevents little ones from accessing the button. The button is easy to access for adults.

cybex sirona m with sensorsafe 2.0 convertible car seat review - the rear tether and the user manual stow in a pocket on the back of...
The rear tether and the user manual stow in a pocket on the back of the Cybex.
Credit: Abriah Wofford

LATCH Storage


The LATCH connectors stow under the padding of the seatback, and the tether has a covered pocket on the back. The location and design keep the straps and anchors out of the way when you move the seat or install it using the vehicle belt. The user manual tucks in the same back pocket location as the tether strap.

Cover


The cover of the Cybex can be removed to machine wash in cold water. The nicer finished look of the fabric tucking under the shell makes it a little more difficult to remove the cover, but it is worth the effort.

cybex sirona m with sensorsafe 2.0 convertible car seat review - the shell of the cybex is fairly enclosed with an opening for the...
The shell of the Cybex is fairly enclosed with an opening for the belt pathway only.
Credit: Abriah Wofford

Comfort/Quality


The Cybex is comfortable and looks to be of nice quality. With a smaller price tag than other seats with similar scores, the Cybex proves you can get more for less, but not budget-price less.

cybex sirona m with sensorsafe 2.0 convertible car seat review - the cybex comes with a cup holder that can be removed and cleaned in...
The Cybex comes with a cup holder that can be removed and cleaned in your dish washer.
Credit: Abriah Wofford

The Cybex has thicker padding than average and is fairly firm for good support. The fabric is slick and soft and feels like it will be easy to wipe clean. The fabric fits the padding and shell well with a look that isn't overly tight or frumpy. The shell has a nice look and feel that is enclosed so no dirt or gunk can find a home in small places. The base is also smooth, and there are no edges to cause damage to the vehicle seat. Overall the seat has a clean but functional look.

cybex sirona m with sensorsafe 2.0 convertible car seat review - the cybex is both on the heavy side and wider. while not the...
The Cybex is both on the heavy side and wider. While not the heaviest or widest in the group, its size could be limiting if you need to carry it or require 3 safety seats across your back seat.
Credit: Abriah Wofford

Weight


The Cybex weighs about 23.5 lbs depending on configuration, making it heavier than average for the group. It is also relatively wide at 19.6 inches, which may not be an issue if you only need to fit one or two car seats in your back seat. However, if you need three seats or two seats and a third person, it could be too wide to work well.

Should You Buy the Cybex Sirona M with SensorSafe 2.0?


Unless you are simply attracted to the gadget of the SensorSafe portion of the seat, it isn't the best seat available, and most of its test results were uninspired and below average. This seat has a short rear-facing life, which is the safest position for little ones, and it has disappointing crash test results. As one of the lowest-scoring options in a big group of potential choices, we can't see any reason to recommend this car seat to a friend. No matter what your car seat goals are, we believe there are better options available.

What Other Convertible Car Seat Should You Consider?


If you love Cybex, the Cybex Sirona S earned a slighter higher score overall and has better crash test results. However, it still isn't a super impressive seat, and we think there are better options to be had elsewhere. It also sports a significantly higher price which could stop those on a budget from choosing it. Our personal favorites include the Graco Extend2Fit, with one of the highest scores for crash test results, and the Britax Emblem that sports a reasonable price, higher crash test results, and is easy to use.

Manufacturer Video



Juliet Spurrier, MD and Wendy Schmitz