In general, most people don’t use a vehicle’s cargo space 100 % of the time. However, some people need a lot of trunk space, maybe because they travel so much, carry sales and marketing items, play golf, or deliver pizza or other stuff. Whatever it is they are moving, a large cargo capacity would then definitely be a requirement.
One thing, though. Some cargo space figures from car manufacturers can turn out to be misleading. It’s not to say they are inaccurate, but they may not reflect the kind of cargo space you are expecting. This confusion stems from the Society of Automotive Engineers (SAE) industry standard for measuring a car’s cargo or trunk space.
First introduced in 1973, the J1100 standard for cargo capacity has been revised multiple times, the last time in 2009. Though there is the latest revision, manufacturers can choose which version to follow, as long as this information is stated unambiguously.
This is why it’s important to read your vehicle owner’s manual carefully to determine which version the cargo space measurement is based on. One can only hope that it is actually stated there.
It turns out that automakers measure trunk space with standardized blocks that simulate luggage, and are also different from each other. Certain manufacturers’ blocks have simulated luggage handles while others do not.
This alone can affect how the pieces of luggage are stacked upon each other. Measurements using these pieces also do not consider the empty spaces around them, where items in plastic bags can fit.
Open cargo spaces, especially those in hatchbacks, station wagons, and sport-utility/crossover vehicles are measured differently. The standard formula for volume with comprises the measurements of length, width, and height. While this seems reasonable, protruding wheel wells, seatback angle, and other factors are not considered. A rear seatback bent so far back can significantly affect and reduce the cargo space’s volume, probably by as much as 20 %.
A manufacturer might claim that the new SUV you’re looking at has more cargo capacity than your old one. Still, in reality, it could only be achieved by stacking luggage items so high that your rearview is already obscured. It’s also possible that a vehicle such as a station wagon or crossover can achieve so much cargo space only by pulling the rear seats way forward, making the rear seats so uncomfortable for fully grown adults that only dwarves or little children can sit in the back.
That being said, you don’t always have to rely on manufacturers’ claims about cargo space. Just take a tape measure and calculate the cargo space by yourself, making sure you factor in curved interior panels, protrusions, your own preferred maximum stacking height for suitcases and boxes (in the case of open cargo spaces), and the danger of luggage flying around the interior (which necessitates the use of cargo nets and mounting points).