Capacity is the number every product page leads with, and it is the least useful one. A van has more cubic feet than most builders fill; what runs out is accessible cubic feet. Sort your gear into what you touch daily, weekly, and twice a season, then assign zones in that order. Daily items belong at the slider door at standing height. Weekly items go in the garage. Twice-a-season gear can live anywhere that is annoying to reach, and that includes the roof. Builders who skip this step end up with a full van and nothing findable, which is the actual failure mode.