Trunk comparison: Audi Q3 vs Mercedes Benz GLB

Key Differences

The most noticeable differences concern the vertical dimensions of the GLB: the height of the trunk opening is 3.9 in (13%) larger on the GLB and the depth of the trunk (loading edge to trunk floor) is 1.2 in (33%) greater on the GLB.

Other, smaller differences: The GLB offers about 4.3 in (7%) more loading length with the seats folded down, or 2 in (6%) more depth with the first row upright than the Q3. The narrowest width in the trunk is 2 in (5%) larger on the GLB, while the width of the trunk opening is 2.4 in (6%) larger on the Q3. The loading edge of the Q3 is about 1.2 in (4%) higher above the road than on the GLB.

Impact on Usability

The higher vertical dimensions of the GLB (higher opening and greater interior depth) make it more practical for bulky and tall cargo: larger items can be more easily lifted or stacked through the opening, and the deeper interior surface allows items to sit more stably and be better stacked.

For moves, stacked boxes, or taller items (e.g., plants, boxes, tall furniture parts), the GLB is noticeably more advantageous in everyday use.

The greater distance from loading edge to trunk floor on the GLB can make rolling cargo in and shifting it sideways easier; conversely, a significantly deeper loading floor can make removing very heavy items somewhat less convenient if bending down is required.

The Q3 scores with a slightly wider trunk opening (≈2.4 in), which facilitates loading very wide, flat items (e.g., long shelves, wide boxes). However, the loading edge on the Q3 is somewhat higher, which makes lifting heavy loads into the trunk more difficult compared to the GLB.

Conclusion

For frequent transport of tall or stacked cargo, the GLB is the more practical choice due to the larger opening and deeper interior. For wide, flat items, the Q3 can offer advantages with its wider opening but usually requires more lifting due to the higher loading edge.