Trunk comparison: BMW i4 vs Kia Sportage

Key Differences

When it comes to trunk dimensions, clear focal points emerge: The BMW i4 offers slightly longer cargo space measurements with the seats folded down (+2.8 in / 4%) and with the first row upright (+3.1 in / 9%), but these differences are small. Noticeably larger are three deviations favoring either the Kia or the BMW:

• Width at the narrowest point: Kia +6.3 in (18%) — the Kia is significantly wider in cross-section.
• Width of the trunk opening: Kia +4.3 in (12%) — the Kia's opening is noticeably wider.
• Trunk depth (loading edge to trunk floor): BMW +3.9 in (900%) — the BMW has a significantly deeper interior below the loading edge.

Other differences under 10%: The Kia's trunk opening height is +2.4 in (9%) higher, and the Kia's loading edge is +0.8 in (3%) higher above the road than the BMW's.

What are the implications of these differences for usability?

The width at the narrowest point and the opening width are crucial for loading large, wide, or bulky items.

Thanks to the wider opening and larger cross-section, bulky cargo is easier to slide and turn inside the Kia Sportage — such as large boxes, flat furniture parts, or wide sports equipment. Tapering items are more likely to fit into the Kia without complicated rearranging or disassembly.

The significantly greater trunk depth of the BMW means the interior below the loading edge is deeper.

Practically, this means more vertical usable space behind the loading edge, better room for taller stacks below the opening, and often a lower center of gravity for the load. Combined with the slightly lower loading edge of the BMW, heavy items are easier to lift or roll into the vehicle.

The slightly longer cargo space measurements of the BMW (4–9%) have only a moderate effect — they provide more usable length but are less decisive in everyday use than width and opening.

The somewhat higher opening of the Kia (+2.4 in, just under 10%) slightly eases inserting tall, very bulky items but does not impact as much as the mentioned width and depth differences.

Conclusion

For wide or bulky items, the Kia Sportage is the more practical choice due to the wider trunk opening and larger cross-section.

For deeper, high-stackable, or heavy cargo, the BMW i4 offers advantages in handling and storage volume below the opening with its significantly greater trunk depth and lower loading edge. Small length and height differences are secondary and have only a minor impact on everyday usability.