Trunk comparison: BMW X5 vs Mercedes Benz GLB

Key Differences

The measurable differences between the BMW X5 and Mercedes-Benz GLB are generally small to moderate: The BMW X5 offers about +3.5 in more trunk length (5% and 9%) with the seats folded down and with the first row upright, respectively, and at the narrowest point a +2 in (5%) greater width.

The width of the trunk opening is +1.2 in (3%) larger on the X5. The GLB's trunk opening is +3.1 in (10%) higher than the X5's, and the X5's load lip sits +2.8 in (10%) higher above the road.

Notably, the depth between the load lip and trunk floor is significantly different: The GLB is +4.3 in (1100%) higher here than the BMW X5.

Impact on Usability

The very large difference in depth (load lip → trunk floor) in the GLB is the practically most important difference: a significantly lower trunk floor means that items in the GLB sit further "below" the load lip.

This has two consequences: First, the retention effect increases—loose cargo is better protected against sliding outwards. Second, loading and unloading bulky or heavy items can be more cumbersome because more lifting or levering effort is required, especially if the load lip is relatively high.

The X5 has a higher load lip above the road (+2.8 in), which makes lifting heavy loads more difficult, while the GLB's lower load lip facilitates placing and sliding luggage.

At the same time, the X5 offers slightly more length and marginally more width at the narrowest point, which slightly favors transporting longer or wider items — however, the differences are small (3–3.5 in) and usually not decisive for everyday use.

In summary: For easy handling of heavy or bulky loads, the GLB is advantageous due to the lower load lip, but the much greater depth to the trunk floor changes loading behavior (better containment but deeper lifting/reaching).

The X5 offers somewhat more usable length and width but requires more lifting effort due to the higher load lip.