What is the Overall Width of the Thule Motion 3 Low Profile Rooftop Cargo Box

Question:

What is the width of this roof box where it sits on the rails? Thanks!

asked by: TB

Expert Reply:

Hey TB, thanks for reaching out!

The Thule Motion 3 Low Profile Rooftop Cargo Box # TH37PN has an overall width of 35". Since this is a bigger item and it's designed to be full of cargo, you'll want the box itself to sit on the rails - you won't want to have it hanging off the rails at all.

Let me know if you have any other questions!

expert reply by: Jon G

2/26/2025

The box won't hang off the rails, my apologies on the poor vernacular. I have Yakima Railbars so there's rather large pieces of plastic at either end of the cross bars. I have 31" of exposed metal crossbar for the box to sit on, and 38" rail to rail length including the plastic (Subaru Crosstrek). So the box should fit between the factory rails, but didn't know if it would fit on the Yakima Railbars.

Jon G.

2/27/2025

@Tb Ah, I see. Thanks for reaching back out!

2/27/2025

@JonG Any chance you could measure the width of the box on the rear of the two cutouts where the box would sit on the cross bars? Thule's chart has the width of the box at 35.25", but it appears that the upper shell is wider than the bottom. Any help is appreciated.

Jon G.

2/27/2025

@Tb I took some measurements and that track where the mounting clamps sit are about 5" in from the outside of the box so you're looking at saving about 10" with the width there.