Trunk comparison: BMW X3 vs BMW X4

Biggest Differences

Three differences stand out clearly from the data: The trunk opening of the BMW X3 is 3.5 in (13%) higher than that of the X4, the depth of the trunk (loading edge → trunk floor) in the BMW X4 is 3.1 in (700%) greater, and the loading edge of the BMW X4 is 3.5 in (13%) higher above the road than in the X3. All other specified differences (e.g., cargo length with/without folded seats or width differences) are below or at 10% and are therefore less significant.

Impact on Usability

The higher trunk opening of the X3 makes loading tall or bulky items significantly easier: bulky boxes, plants, or larger cartons fit more easily through the opening, and you have to bend less when loading. This makes the X3 overall more practical for regularly transporting tall cargo.

The greater depth between the loading edge and trunk floor in the X4 means more usable depth inside; longer or flat-lying items can be pushed further back, and the volume near the floor is noticeably larger.

Combined with the coupe-like narrower opening profile, this gives the X4 advantages when it comes to volume in depth, but not necessarily for loading large, tall items.

The higher loading edge of the X4 makes loading heavy items more strenuous: suitcases, toolboxes, or machines have to be lifted higher, and rolling luggage reaches the cargo floor less easily than with the lower loading edge height of the X3. Practically, this means: the X4 tends to offer more usable depth, the X3 offers easier access and better vertical usability.

Conclusion: Those who frequently load tall or bulky items and prefer easy access benefit more from the BMW X3. Those who need flat-lying, deeper stowage and somewhat more interior depth and can live with a higher loading edge will find the BMW X4 the more suitable solution.