Trunk comparison: BMW 3 Series Touring vs BMW X3

Key Differences
The BMW X3 offers a cargo space that is 1.2 in (2%) longer with the seats folded down, while the BMW 3 Series Touring has a usable length that is 2 in (5%) longer with the first row of seats upright.
The trunk opening of the X3 is 2.8 in (10%) higher than that of the 3 Series Touring; the depth from the loading floor to the loading edge is only 0.4 in (0%) higher in the 3 Series Touring. Significantly larger in the X3 is the usable width: at the narrowest point, the trunk is 5.9 in (16%) wider and the width of the trunk opening is 4.7 in (12%) greater than in the 3 Series Touring. The loading edge of the X3 is also 3.9 in (17%) higher above the ground than in the 3 Series Touring.
Impact on Usability
The greater widths (inside and at the opening) in the X3 make it significantly easier to store wide or irregularly shaped items: furniture parts, wide boxes, or strollers fit more easily through the opening and require less maneuvering space inside the cargo area.
The 3.9 in higher loading edge of the X3 makes lifting heavy loads into the trunk more strenuous and complicates the easy rolling in of suitcases or shopping carts; the Touring model with the lower loading edge is more convenient here for frequent loading and unloading.
The length differences (±3–2 in) and the 0.4 in depth deviation are practically negligible and only minimally affect everyday usability. The 2.8 in higher trunk opening of the X3 can somewhat simplify loading tall items but is quantitatively less decisive than the width and loading edge differences.