"Does passenger capacity include the trunk area when the seats are folded?"
Passenger and cargo capacity are separate measurements. Both are expressed in cubic feet, and increasing one reduces the other.
Passenger room includes all seating areas, so if a vehicle has three rows of seats, it naturally will have more passenger volume. The three-row 2013 Toyota Highlander SUV, for example, has 145.7 cubic feet of passenger volume, and the two-row 2013 RAV4 has 101.9 cubic feet.
With the Highlander, when all three rows are in use the cargo volume left at the rear is a skimpy 10.3 cubic feet. Add that to the passenger volume, and the Highlander has total interior volume of 156 cubic feet under the EPA's measuring standards used to place vehicles in size categories.
Fold the Highlander's third row and cargo volume increases to 42.3 cubic feet. Fold the second row as well and the cargo space behind the front seats grows to the maximum 95.4 cubic feet.
Increasing cargo volume by folding seats, of course, reduces the passenger space by corresponding amounts.Related