Trunk comparison: BMW X3 vs BMW X5

Key Differences

The most noticeable difference is the height of the trunk sill: The trunk sill of the BMW X5 is 3.5 in higher than that of the BMW X3 (about +13%).

All other measured dimensions are significantly smaller and within single-digit percentages: The trunk of the X5 is about 3.1 in (4%) longer with the seats folded down and about 3.5 in (9%) longer with the first row upright than the X3. The height of the trunk opening is only 0.4 in (1%) higher on the X5, and the depth (from trunk sill to trunk floor) is 0.4 in (0%) greater.

The narrowest interior width is the same in both models; the width of the trunk opening is 1.2 in (3%) larger on the X3.

Impact on Usability

The significantly higher trunk sill of the X5 has the most visible practical consequences: loading and unloading heavy or bulky items requires more effort and lifting height, which is noticeable when frequently transporting furniture, heavy shopping bags, or building materials.

For people with back problems or limited mobility, the X3 with the lower trunk sill is more practical. Additionally, the slightly larger opening width of the X3 (1.2 in) makes it easier to load wider items despite overall similar interior dimensions.

The somewhat greater cargo length of the X5 (4–9%) provides more usable space for long items, but the difference is moderate and unlikely to be decisive in most everyday cases. Since the width at the narrowest point and trunk depth are nearly identical, the shape of the usable cargo space remains similar.

In summary: Those who regularly transport heavy, frequently loaded cargo or value easy handling benefit more from the X3; those who need a bit more cargo length and accept the higher trunk sill will find greater usable capacity in the X5.