Radian 3QXT › fit in › Mazda CX-5

Will the Diono Radian 3QXT fit in a 2017–2024 Mazda CX-5?

Yes — the Diono Radian 3QXT fits a 2017–2024 Mazda CX-5, with a caveat.
The Radian 3QXT is about 17" wide; the CX-5's usable rear bench is about 49". It fits one rear position comfortably. Three across is tight (51" needed vs 49"). Note: rear legroom here is limited, so a rear-facing install may crowd the front passenger.

17"Radian 3QXT width

49"CX-5 rear bench

Tightthree across

★★★☆☆NHTSA Ease-of-Use

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What fits this CX-5

One seat, rear position: Yes. The Radian 3QXT installs in an outboard rear position of a 2017–2024 Mazda CX-5, though you may slide the front seat forward for rear-facing.
Three across: Tight — three need ~51" against only ~49". A narrower seat is the better bet.
Modes this seat covers: rear-facing → forward-facing → booster.
LATCH: lower anchors up to 40 lb; the CX-5 has 2 lower-anchor positions.

ℹ️ Informational only — built from NHTSA public car-seat ratings and published seat/vehicle dimensions. This is not a safety certification and not a substitute for the seat and vehicle manuals. Always confirm the fit and install yourself before every trip. The Radian 3QXT's width (Diono published spec (17 in)) and the CX-5's rear-bench width (Mazda dimensions + owner measurements (approx)) are both approximate — confirm with a test-fit before buying.

Common questions

Will the Diono Radian 3QXT fit in a 2017–2024 Mazda CX-5?

Yes — the Diono Radian 3QXT (17" wide) fits a single rear seating position in a 2017–2024 Mazda CX-5. Because this vehicle has limited rear legroom, a rear-facing install may require sliding the front seat forward. Three across is tight — its rear bench is about 49" and three of these would need 51".

Can you fit three Radian 3QXTs across a CX-5?

Probably not — three Radian 3QXTs need about 51" but the CX-5's usable bench is only about 49". Consider a narrower seat — see our narrowest-seats guide.

Sources: seat ratings & modes — NHTSA (pulled 2026-06-17); dimensions — manufacturer specs and owner measurements. Informational only — built from NHTSA public car-seat ratings and published seat/vehicle dimensions. This is not a safety certification and not a substitute for the seat and vehicle manuals. Always confirm the fit and install yourself before every trip.