Hey All,

I have a 2018 Mazda CX9 GT (factory flush rails) and Thule 47 inch Aerobars.

I'm looking at Thule roof boxes. I'm thinking about the Thule Motion XT series.

Regarding size, any feedback on the size: Large (16 cf), Extra Large (18 cf), or XXL (22cf)?

Thanks!

 

The critical measure is from the back of the box to the opened liftgate. I think any you mention will fit. I have a Thule Motion XT Alpine on factory cross bars, and it fits fine.

What length do you need to fit what you'll carry? What height? Any width is OK unless you'll parallel a rack for a kayak, bike, etc.

 

Another thing to consider is if you will need the box up there for both directions of your trip. I ask this because last night I returned from a ~4,500 mile road trip; 2,200 miles with stuff on top and the remaining miles with the rack system stowed inside the car. In my case I used the Thule Interstate cargo bag, filled it almost to the bursting point on the way out, and then stowed the full rack system inside the car for the return trip. On the way out I averaged 22 mpg, on the way back I averaged 33 mpg.

 

Thanks for your reply.

We are a family of 5, so mostly concerned with being able to carry our luggage out of the cabin. Also, skis and stuff for winter sports.

I believe that the Alpine is the longest Thule Motion. If it fits your CX9 well, I believe that the Motion XT XL/XXL would fit fine as well.

Any pics of it installed on your CX9?