Disclosure: This article contains affiliate links. I may earn a commission at no extra cost to you.
The Thule Motion 3 L is the 450-liter size in Thule’s Motion 3 line, and it’s the box most Subaru owners end up comparing first. This guide covers its published size and weight, how it fits against each Subaru’s roof limit, and what to check before you buy. It’s built from Thule’s listed specs and Subaru’s own roof ratings. On the Amazon listing, make sure the L size is the one selected.
Thule Motion 3 L Specs
| Spec | Thule Motion 3 L |
|---|---|
| Capacity | 450 L (about 16 cu ft) |
| Exterior size | 76.5 x 34.2 x 16.5 in (194 x 87 x 42 cm) |
| Weight | About 43.6 lb (20 kg) |
| Box load rating | 165 lb (75 kg) |
| Longest skis | About 180 cm |
| Opening | Dual-side |
Specs are the figures retailers list for the Thule Motion 3 L, and they can differ by a small amount between sellers. Check Thule’s own page for your exact box before you rely on a number.
How It Fits Each Subaru’s Roof Limit
The box weighs about 44 lb empty, and that comes out of your roof’s driving (dynamic) limit before you add the crossbars or any gear. The table below uses the limits from our roof weight limits guide and subtracts only the box.
| Vehicle | Driving roof limit | Left after the box (before crossbars and gear) |
|---|---|---|
| Outback 2018-2025 (most trims) | 150 lb | about 106 lb |
| Forester 2019-2024 (raised rails) | 176 lb | about 132 lb |
| Crosstrek 2018-2023 | 150 lb | about 106 lb |
| Crosstrek 2024-2026 (raised rails) | 165 lb | about 121 lb |
Subtract the weight of your crossbars too, then pack to what’s left. A box rated for 165 lb doesn’t raise the car’s limit. Your lowest rating always wins, as covered in How Much Weight Can Subaru Crossbars Hold?
Hatch Clearance and Height
A box this long is easy to place too far back. Push it forward until the open rear hatch clears it, which depends on your crossbar spacing and how far the box can slide. Our guide on how far forward a cargo box should sit walks through the check. The Outback’s longer roof gives the most room, and the Crosstrek’s shorter roof gives the least.
At 16.5 in tall, it adds that much above your crossbars. Measure your garage opening against the full installed height before you buy. The garage clearance guide lists real heights for this and other boxes.
Crossbars
The Motion 3 clamps to most round, square and aero bars. Factory bars usually work but can limit how far forward the box slides. Aftermarket bars give you more spacing options, such as the Thule WingBar Evo. See OEM vs Aftermarket Crossbars for the tradeoffs.
What It Holds
- Soft gear packs best: duffel bags, sleeping bags, jackets and tents.
- Rigid items are harder: bins and big coolers waste space because the ends taper.
- Skis: up to about 180 cm.
Duffel bags sized for roof boxes and packing cubes make the most of the center of the box.
Who It Fits and Who Should Look Elsewhere
- Good fit: Outback and Forester owners who want one large box for road trips and camping, and who have the garage height.
- Tighter fit: Crosstrek owners, because of the shorter roof and the lower limit on 2018-2023 models.
- Look elsewhere: if height is the issue, a lower box like the Motion 3 XL Low is shorter. See the Outback cargo box buyer’s guide and Thule vs Yakima to compare.
Storing It Between Trips
It’s about 6.4 ft long, so plan wall or ceiling space. A wall mount rack or a ceiling hoist keeps it off the floor. Two people make lifting it onto the roof much easier.
Leave a Reply