8Rank 08 of 8 · Best i-Size Car Seats
Britax Römer Britax Römer Dualfix 5Z + Vario Base 5Z
Included as a warning. The second-most-expensive seat here at €540, and the worst-performing: 3.2 overall, with ADAC citing elevated injury risk in the frontal crash.
5.3BPR score
- €540Price
- 3.2 — safety sub-score 3.5 (ADAC/ÖAMTC 05/2026)ADAC / ÖAMTC overall grade
- 8 of 8in Best i-Size Car Seats
- 5.3BPR score 0–10
Review
What this product is
Written after the analysis, from the same sources the score is built on: the manufacturer's documentation, available studies and verified owner feedback.
We have included this seat deliberately, because it is from a brand many parents treat as a default and it produced the worst result in this ranking.
ADAC graded it 3.2 overall in the May 2026 round, with a safety sub-score of 3.5 driven by what ADAC describes as erhöhtes Verletzungsrisiko beim Frontcrash — elevated injury risk in the frontal crash. Handling scored 2.4, ergonomics 2.3, and harmful substances 1.9.
That 1.9 for harmful substances is also worth noting. It is the weakest toxicology result of any seat here — every other seat in this ranking except the Maxi-Cosi scored a clean 1.0. ADAC applies harmful-substance results as a progressive downgrade to the overall grade, so this figure is pulling the result down further on top of the crash performance.
The comparison that makes the point: this seat costs €540 and scored 3.2. The Graco Turn2Me DLX costs €149 and scored 2.4, with a safety sub-score of 2.1 against this seat's 3.5. Nearly four times the price, and a materially worse crash result.
The specification is otherwise unremarkable. Approval is 61 to 105 cm — note that this is not from birth, unlike most seats here — with rear-facing from 61 to 105 cm and forward-facing from 76 to 105 cm, 360° rotation, and an ISOFIX base with support leg.
Two specification inconsistencies we could not resolve. Britax's own page shows a maximum weight of 18 kg in the body text and 19 kg in the page metadata. And ADAC's page mentions 5.2 kg, which is implausible for a complete rotating seat and is probably the shell without the Vario Base — we have not stated a seat weight as a result.
None of this means Britax Römer builds bad seats generally. It means this model, in this test round, performed poorly — and that a respected brand name is not a substitute for checking the current grade.
Technical data
Specification
Figures from the manufacturer's documentation, verified against available outside sources. Values we could not confirm are marked as declared.
- Approval
- UN ECE R129 (i-Size)
- Height range
- 61-105 cm - NOT from birth
- Weight limit
- 18 kg per Britax body text; 19 kg per page metadata - unresolved
- Orientation
- Rear-facing 61-105 cm, forward-facing 76-105 cm, 360° rotation
- ADAC overall grade
- 3.2
- Safety (Sicherheit)
- 3.5 - elevated frontal crash injury risk
- Handling (Bedienung)
- 2.4
- Ergonomics (Ergonomie)
- 2.3
- Harmful substances (Schadstoffe)
- 1.9
- Installation
- ISOFIX Vario Base 5Z with support leg
- Seat weight
- Not reliably established
- Test round
- May 2026
- Market price
- approx. EUR 540 (ADAC)
Component scores
Where the score
comes from.
Four components, equal weight, each on a 0–10 scale and each resting on a named source. The overall score is their mean — the full procedure is in the methodology.
What we liked
- Handling 2.4 — better than several higher-scoring seats here
- Ergonomics 2.3, mid-pack
- 360° rotation with rear-facing to 105 cm
- ISOFIX base with support leg
- Established brand with a wide European service and retail network
Worth knowing
- 3.2 overall — the worst result in this ranking
- Safety sub-score 3.5, with ADAC citing elevated frontal-crash injury risk
- Harmful substances 1.9, the weakest toxicology result here
- €540 — nearly four times the price of a better-scoring seat
- 61-105 cm, so not usable from birth
- Britax's own page gives conflicting weight limits (18 vs 19 kg)
Comparison
How it compares
within the category
All values come from the same analysis and are comparable only within the category Best i-Size Car Seats.
| Product | Score | ADAC / ÖAMTC overall grade | Price |
|---|---|---|---|
| Maxi-Cosi Pebble S + FamilyFix STop score | 8.8 | 1.8 (ADAC/ÖAMTC 05/2025) | €330 |
| Britax Römer Dualfix 5Z + Vario Base 5ZThis product | 5.3 | 3.2 — safety sub-score 3.5 (ADAC/ÖAMTC 05/2026) | €540 |
| Category average8 products analysed | 7.9 | — | — |
FAQ
Frequently asked questions
Should I avoid Britax Römer entirely?
No. This is one model in one test round. Britax Römer is a long-established manufacturer with a broad range, and other models in that range have tested well. What this result demonstrates is that brand reputation does not transfer between models — check the current ADAC grade for the specific seat you are considering, every time.
Why does a harmful substances score of 1.9 matter when it is still 'good'?
Because ADAC applies it as a progressive downgrade to the overall grade rather than as a weighted component. Anything worse than "good" pulls the verdict down, and a poor result sinks it outright. The rationale is exposure: a child sits in this seat for years, in a hot car, gripping and mouthing the fabric. ADAC screens for PAHs, phthalates, flame retardants, phenols, organotin compounds, azo dyes, heavy metals and — since 2025 — PFAS.
From the same ranking
Other products in Best i-Size Car Seats.
The same protocol, the same key parameter, the same set of sources.
-
No. 018.8/ 10
Maxi-Cosi Pebble S + FamilyFix S
The best infant carrier here at 1.8, with a 3.2 kg shell and ADAC's explicit note of low…
-
No. 028.7/ 10
Joie i-Spin Safe
The best safety result in this ranking: 1.6 overall with a safety sub-score of 1.2 and a clean…
-
No. 038.4/ 10
Joie i-Level Pro
A €199 infant carrier with a 157° near-flat recline and clean 1.0 toxicology. Unusually, it…
-
No. 048.4/ 10
Graco Turn2Me DLX i-Size R129
The value finding of this research: €149 for a rotating 40–105 cm seat with identical ADAC…