Radian 3QXT › fit in › GMC Sierra 1500 Crew Cab
Will the Diono Radian 3QXT fit in a 2019–2024 GMC Sierra 1500 Crew Cab?
Yes — the Diono Radian 3QXT fits a 2019–2024 GMC Sierra 1500 Crew Cab.
The Radian 3QXT is about 17" wide; the Sierra 1500 Crew Cab's usable rear bench is about 56". It fits one rear position comfortably. Three even fit across the back (51" needed vs 56").
The Radian 3QXT is about 17" wide; the Sierra 1500 Crew Cab's usable rear bench is about 56". It fits one rear position comfortably. Three even fit across the back (51" needed vs 56").
17"Radian 3QXT width
56"Sierra 1500 Crew Cab rear bench
Yesthree across
★★★☆☆NHTSA Ease-of-Use
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What fits this Sierra 1500 Crew Cab
- One seat, rear position: Yes. The Radian 3QXT installs in an outboard rear position of a 2019–2024 GMC Sierra 1500 Crew Cab with room to spare.
- Three across: Yes — three need ~51" against a ~56" bench. Test-fit; three-across is decided by half-inches.
- Modes this seat covers: rear-facing → forward-facing → booster.
- LATCH: lower anchors up to 40 lb; the Sierra 1500 Crew Cab has 3 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 Sierra 1500 Crew Cab's rear-bench width (Typical for pickup — crew cab — approximate, verify install in your vehicle) are both approximate — confirm with a test-fit before buying.
Common questions
Will the Diono Radian 3QXT fit in a 2019–2024 GMC Sierra 1500 Crew Cab?
Yes — the Diono Radian 3QXT (17" wide) fits a single rear seating position in a 2019–2024 GMC Sierra 1500 Crew Cab. Three of them also fit across its roughly 56" rear bench.
Can you fit three Radian 3QXTs across a Sierra 1500 Crew Cab?
Yes — three Radian 3QXTs need about 51" and the Sierra 1500 Crew Cab's usable bench is about 56". It's close, so test-fit before buying.
Sources: seat ratings & modes — NHTSA (pulled 2026-06-18); 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.