The move from sedans to crossovers is normally explained in one word: space. Buyers wanted more of it, so they bought taller cars.
The EPA measures interior volume in two separate numbers — the cabin and the boot — and reports them independently. Split the comparison that way and the explanation stops working.
| EPA class | Models | Passenger volume | Cargo volume | Cargo as % of total |
|---|---|---|---|---|
| Small SUV | 358 | 106 cu ft | 26 cu ft | 20% |
| Small station wagon | 633 | 96 cu ft | 22 cu ft | 19% |
| Large car | 1,401 | 108 cu ft | 17 cu ft | 14% |
| Midsize car | 2,199 | 100 cu ft | 14 cu ft | 13% |
| Compact car | 1,826 | 92 cu ft | 13 cu ft | 12% |
| Subcompact car | 279 | 86 cu ft | 11 cu ft | 11% |
A large car has more cabin than a small SUV — 108 cubic feet against 106 — and 65% of its luggage space.
The trade was never about people
That first comparison is the whole finding. If crossovers had won because they hold occupants better, the passenger column would show it. It shows the opposite.
What the crossover actually delivers is the second column. 26 cubic feet against 17 is not a marginal gain — it is half again, and it comes from geometry rather than from the vehicle being bigger overall.
A boot is a horizontal box with a lid, bounded by the rear screen and the parcel shelf. Anything taller than the opening does not go in. A crossover's rear is vertical, opens to the roof, and the load bay continues upward until it meets the ceiling — so the same footprint holds a different quantity of things.
The ratio column ranks by shape, not by size
Read the last column and the ordering is not by vehicle size at all. Small SUVs beat large cars. Small station wagons beat large cars. Subcompacts come last.
What sorts that column is how vertical the back of the car is. Wagons and SUVs put a fifth of their interior volume into the load bay; sedans manage an eighth.
Which is why a station wagon — a shape the American market largely abandoned — sits second on this table with 96 cubic feet of cabin and 22 of luggage. Mechanically it is a sedan; geometrically it is a crossover with a lower roof.
What this changes about the choice
It turns one decision into two, and they have different answers.
If the constraint is people — four adults on a long drive — a large sedan matches a small SUV on cabin volume, sits lower, handles better and costs less to fuel. There is no space argument for the crossover here.
If the constraint is what goes behind them, the crossover wins by 53% and nothing about the sedan closes that gap. A pushchair, a large dog, a bicycle with the front wheel off, anything flat-packed — these are height problems, and only one of the two shapes has height.
The honest summary is that crossovers won on luggage and were sold on space. Those are not the same claim, and the EPA has been measuring them separately the whole time.
One caveat on the numbers
These are class averages across 6,696 four-door models from 2010 onward, and individual vehicles vary considerably inside each class. A specific large sedan can out-carry a specific small SUV.
What holds is the direction: comparing a sedan and a crossover of similar footprint, expect similar room for people and substantially more room for luggage in the taller one.
And whichever shape you settle on, the individual car's history matters more than its class. A free VIN check covers that side.
Frequently asked questions
Do SUVs have more interior space than sedans?
Not for passengers. Across 6,696 four-door models, large cars average 108 cubic feet of passenger volume against 106 for small SUVs. The difference is entirely in cargo: 17 cubic feet against 26, because a hatchback opening and a vertical load bay hold far more than a boot of the same footprint.
What is passenger volume?
An EPA measurement of the total space enclosed by the cabin — the air around the occupants, measured to a standard procedure so it can be compared between vehicles. It is reported separately from cargo volume, which is why the two can be examined independently.
Which class carries the most luggage relative to its cabin?
Small SUVs, where cargo is 20% of total interior volume, followed by small station wagons at 19%. Subcompact cars are lowest at 11%. The ratio tracks body shape almost exactly: the more vertical the rear of the car, the more of its volume is usable for luggage.
Should I buy a sedan or a crossover?
If the constraint is people, a large sedan matches a small SUV and usually costs less to run. If the constraint is what you put behind them — a pushchair, a dog, flat-pack furniture — the crossover's shape wins by half again, and no amount of sedan boot space closes it.
Denis Kataev is a serial solopreneur and the founder of ForCar. With 15+ years in software engineering and 10 years in SEO, he builds data-driven products end to end — backed by a sharp eye for design. At ForCar he mines proprietary vehicle datasets, turning raw numbers into buying advice you can actually trust.
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