Cybex Sirona S VS Eternis S

NOTE : Product prices, availability, ratings and save money information are accurate as of the date/time indicated on post time (as seen right bellow the tittle) and are subject to change. Any price, ratings, availability and save money information displayed on Amazon Site at the time of purchase will apply to the purchase of this product.

Parents know the importance of safety car seats for their children but many of us have to put some effort into utilizing them due to the complicated system. For those who want to use a more convenient safety seat, the Cybex Sirona S Vs Eternis S are ideal options to go for. These seats are easy to install and come with special features for the ease of use too. If parents are wondering which of them to go for, here are what you may want to know first.

In this comparison, we are going to talk about:

  • Why Safety Car Seat is Necessary
  • What are Cybex Sirona S and Eternis S
  • How are the Seat of Cybex Sirona S and Eternis S
  • How are the Installation of Cybex Sirona S and Eternis S
  • How are the Fit of Cybex Sirona S and Eternis S
  • What else Cybex Sirona S and Eternis S can offer
  • Cybex Sirona S Vs Eternis S

Safety Car Seat for Children

Having our own vehicle is undeniably convenient because we can travel easily and carry lots of things with us from transporting people to goods and moving from one place to another. In modern days almost everyone has their own motor vehicle and while this is great for our mobility, it also means more crowded space. The road once we knew was quite empty may now become congested at certain hours. Unfortunately it can also contribute to road accidents.

Our car is designed to minimize the impact when they get into accidents. For example the crumple zones are the areas of your vehicle that are designed to crush in a controlled way during collision as it takes the time to change momentum of the driver themselves as well as passengers to reduce force involved. The seatbelt and airbag are additional features to improve safety in modern cars. The latter may act like a cushion and improve the safety purpose with the proper deployment.

However, all of them are made for adults and designed for our build rather than the children who also may present in the vehicle during the accident. In the past there were so many casualties from improper restraining. This is why a safety car seat is necessary and even mandatory in so many places in order to prevent a more serious impact and effect on the children’s body. Safety car seat needs to be installed in your car and younger children need to be restrained in the seat.

Safety car seats are featured with a harness or five point harness to help replace the function of the seatbelt. The harness will secure the passenger when there is an impact so they won’t get ejected or thrown inside the vehicle. The casing of a safety car seat is also useful to improve the impact absorption in order to reduce the energy applied to the body. However, in order to make it work properly, we need to install it securely using the lower anchor, seatbelt, and latch.

Safety car seats are made according to standard and parents have to match the seat fit with their weight and height. The first car seat is infant car seat or convertible seat such as Graco Extend2Fit Vs Britax One4Life. These types of seats are installed in rear position or facing the rear but convertible car seats can be installed facing the front too. When your kid is older, we are going to need a booster seat and the difference is that we will use a seatbelt to secure both the seat and passenger.

Cybex Sirona SCybex Eternis S
Product Dimensions25.3 x 20 x 25.5 inches
25.3 x 20 x 25.5 inches
Shipping Weight30.4 pounds
26 pounds
Best offerCheck priceCheck price

About Cybex Sirona S and Eternis S

There are so many good car seats to consider and parents can find them easily. The decision is all yours based on which seems to work best in the lifestyle and which of them will fit in the budget too. Make sure that the seat is ideal for the weight of the kid because usually it is the easiest way to select one. Additionally, since car seats must be installed properly, parents can choose to have the option that is easier to work with.

Cybex for example is a very famous brand of car seats and many parents are familiar with this company because they are always offering interesting and useful products. The car seats are probably among the most advanced among the similar alternatives but they do cost higher in most chances. What we personally like from their seats is the ease of use because sometimes car seats are a bit stressful to install and remove or adjust. Cybex understands these efforts and offers various convenient systems to help parents.

For new parents who start using safety car seats, Cybex Sirona S and Eternis S are two ideal options to go for. These seats are convertible type meaning we can install the two facing the rear and front after the weight or height is exceeded. They are not cheap but should last for years to come until you need a higher or bigger seat for older children. The main difference between these two however is their installation and also the length on how long we can keep the seat useful.

The best part of Sirona S is their base and the reason why we say so is because it is very much possible to install it once and leave it in the same position until it is no longer in use. On the other hand, Eternis S is similar to a 3-in-1 seat which allows the seat to be kept until booster range. This is very useful especially when the kid grows faster because we may need a booster earlier than expected.

Cybex Sirona S and Eternis S Unit

It is easy to set them apart because they are very different and as you can see, the Sirona S has a bulky base, very different from Eternis S which is more compact and similar to most safety car seats. The seat shape itself is not far different because the case is one from the bottom to the backrest. They can be reclined until several positions for installation and comfort. In comparison the Sirona S is noticeably heavier than the Eternis S.

As for the fabric and cushioning, they are similarly soft and comfortable, featured with the harness, and also inserts for small babies. In addition, the base of the Sirona S is featured with a steel leg and it is used as additional support in order to make the seat more stable. This is necessary because the base is wide and it needs to be supported yet it can cause some issues as well depending on your vehicle’s seat height and floor.

Cybex Sirona S and Eternis S Installation

Moving further, let’s see what the Cybex Sirona S and Eternis S can offer starting from the installation system and as it has been mentioned above, the Sirona S is very convenient. This is because the seat can be rotated on the base itself meaning once getting a secured installation whether it is using a lower anchor or seatbelt, we can keep the base at the same installation. However, the lower anchor weight limit is lower so we highly recommend using the seatbelt for convenience.

In comparison installing a lower anchor is easier with Eternis S, the same with a seatbelt because it is more straightforward to do it. With Sirona S parents will need to use the leg and depending on the height of the seat height, it can be a bit tricky to get the perfect adjustment. The most complicated thing about Sirona S is probably the slot it uses since while it is smart, it is also not as simple as the Eternis S.

Cybex Sirona S and Eternis S Fit

Next is for the fit and since the two are convertible types, we can use them from the early stage. Depending on the baby it may vary so we recommend caregivers to adjust it according to their body first. With inserts newborn can be secured properly on the lowest shoulder setting and when used with lower anchor, they will be ideal for up to 30-35 pounds while seatbelt installation for rear facing mode will be useful for up to 50 pounds.

The weight limit is around 48-49 inches or at least one inch below the top of the headrest of the seat’s shell. When they exceed this weight limit, forward facing is up to 60 pounds but Eternis S is slightly higher at 65 pounds maximum. Depending on the growth rate, your kid may need to move into a booster seat at around 6-7 years old and while we need to move to another seat when using Sirona S, we can still keep using Eternis S as its maximum height capacity is 57 inches and up to 120 pounds in booster mode.

Cybex Sirona S and Eternis S Features

In addition, the standard features such as angle adjustment are present in both Cybex Sirona S and Eternis S, and they do have cup holders on the arm rest. Additionally there is an impact-absorbing feature called LSP or Linear side-impact protection which is designed to absorb 25% more impact from the collision compared to those seats without this feature. Unique to Sirona S and some seats, the 360 degree rotation is helpful so parents can put and remove the kid conveniently while avoiding the need to change the installation for forward facing mode.

Cybex Sirona S Vs Eternis S

Both seats are very useful and convenient but the Sirona S is probably one of the most convenient seats we have seen. Since the seat itself can be rotated, we can install it once and adjust the reclining when needed including when moving to front facing mode. The Eternis S is a 3-in-1 solution which is not as convenient as the Sirona S but will surely last longer because it converts into a booster seat and has a higher weight capacity.

- Convertible Car Seat: The first car seat in the U.S to feature an innovative 360° rotatable seat, the Sirona S makes it quick and easy to switch between rear-facing and forward-facing positions and get your child in and out of the car.
- EasyLock Bar: Reduces the force needed up to 4x for simple and secure car seat installation. Dual-level indicators ensure that your car seat is at the correct recline angle while our load leg can reduce rotation in certain crashes by up to 30%.
- SensorSafe: Built into the chest clip, SensorSafe provides app alerts if a child unbuckles themselves; if the back seat has become too warm or too cold, if a child has been seated for too long, or if the driver accidentally leaves the child behind.
- Superior Protection: Linear side-impact protection (L.S.P.) absorbs up to 25% more impact in a collision compared to the same car seat without L.S.P. extended while the anti-rebound design reduces car seat rebound movement in the event of a crash.
- All-In-One Car Seat: The CYBEX Eternis S is the only seat your child will need from birth and beyond. Featuring rear-facing, front-facing, and belt-positioning booster modes, the Eternis S is designed for use from birth up to 120 lbs.
- Linear Side Impact Protection: The Linear Side Impact Protection system (L.S.P.) absorbs up to 25% more impact forces in certain crashes when compared to the same car seat without L.S.P. extended.
- Patented Reclining Headrest: The Eternis S headrest helps prevent the child's head from falling forward while asleep, keeping the head and neck in a safe position. The headrest also features 12 height settings for easy adjustment as your child grows.
- 10-Year Car Seat: The seamless transitions between modes offers up to 10 years of use from your Eternis S. An in-seat recline helps provide correct ergonomic positioning and extra legroom that lets your child ride rear-facing for longer.


NOTE : Product prices, availability, ratings and save money information are accurate as of the date/time indicated on post time (as seen right bellow the tittle) and are subject to change. Any price, ratings, availability and save money information displayed on Amazon Site at the time of purchase will apply to the purchase of this product.

The decision is all yours since there is no bad option here and we do think if convenience is the most important then Sirona S is a great choice and if parents want to keep using the seat for longer then we recommend getting the Eternis S.

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