I wasted a lot of time researching cargo boxes for my Model Y because I didn’t realize the main criteria for the box was a fixed crossbar spread of 35.5 inches. This narrows the list considerably.
Crossbar Spread: Leading edge of front crossbar to leading edge of rear crossbar
fitlookup.yakima.com
| Box | Price ($) | Volume (cu ft) | Weight (lb) | Capacity (lb) | Actual Capacity (lb) | Max Spread (in) |
| Thule Force XT (L) | 700 | 16 | 41.2 | 165 | 123.8 | 36-1/8 |
| Yakima SkyBox | 679 | 16 | 47 | 165 | 118 | 36 |
| Thule Motion XT (L) | 800 | 16 | 42 | 165 | 123 | 36-7/8 |
| Yakima GrandTour | 779 | 16 | 51.5 | 165 | 113.5 | 36 |
| Yakima RocketBox Pro | 549 | 14 | 40 | ? | < 125 | 40 |
| SportRack Vista (XL) | 400 | 18 | 28 | 100 | 100 | 29-7/8 |
Once this became a requirement the next big factors were price, volume, dimensions, and actual capacity. It seemed as though the top boxes in the Tesla community were the Thule Force, and Yakima GrandTour. With Yakima boxes you can opt to pay $45 for a Same Key System to match your roof rack, but how often are you going to remove your rack? Since the Model Y Roof Rack itself is rated at 165 lb (which also seems to be the weight capacity of many of the larger boxes) we have to remember to consider the weight of the box itself. This is what I call the Actual Capacity. Then there are the dimensions to consider. Many boxes will provide their inner and outer dimensions, the amount and length of skis that will fit. It’s all about what you see yourself carrying – maybe a couple fishing rods.
My personal dilemma was between the Thule Force, and Yakima SkyBox based on availability. I was happy to see REI carried a good selection and could ship them to my local shop quickly. Based on forum reports that SkyBox may or may not fit on Teslas rack, and the larger Actual Capacity – I went with Thule Force XT L. I have taken it on one longer trip and hope to post again with results on my battery range hit. These boxes are a beast to move by yourself. I will be looking into some kind of garage lift system.
I want to include an honorable mention for the SportRack Vista XL. I have found numerous sites that highly rate this box. It is likely that if it was compatible with my crossbars I would have chosen this affordable option. With a savings of $300, 18 cu ft volume, and 100 lb actual capacity it checks so many boxes. I even found an Amazon Answer where someone drilled new holes into the box to accommodate the crossbars and the mechanism to attach seemed plausible. I just didn’t want to experiment here.