Trunk comparison: BMW i4 vs BMW iX1

Key Differences

The most significant differences lie in the interior depth and width: The BMW i4 offers a significantly greater trunk depth (+3.1 in, +400%) while the BMW iX1 is advantageous in width — both at the narrowest point of the trunk (+4.7 in, +14%) and at the trunk opening (+5.9 in, +16%).

Other, smaller deviations: The i4 has a longer loading floor with folded rear seats (+5.5 in, 9%) and with the rear seat upright (+3.1 in, 9%); the trunk opening of the iX1 is slightly higher (+2 in, 7%) and the loading edge of the iX1 sits marginally higher above the road (+0.8 in, 3%).

Impact on Usability

The greater trunk depth of the i4 means more usable space in length/height direction: bulky or higher stackable items can be stored deeper and more stably, longer equipment also benefits from the slightly longer loading floor (each about ~9%).

The result: the i4 is better suited for longer luggage, sports equipment, and when volume in depth is important.

The wider dimensions of the iX1 at the narrow point and at the opening make the model better suited for wide or bulky loads — strollers, wide boxes, or furniture parts fit more easily through the opening and can be loaded more easily sideways.

The slightly higher opening height supports loading tall items; the slightly higher loading edge can minimally complicate lifting heavy loads in.

Conclusion: For more depth- and length-oriented cargo volume, the i4 is advantageous; for wider, bulky cargo and easier side loading comfort, the iX1 is better suited. Smaller differences in opening height and loading edge height only marginally affect practical use.