Trunk comparison: BMW 5 Series Touring vs Mercedes Benz GLB

Key Differences

The models differ most noticeably in the vertical and longitudinal dimensions of the cargo area: The BMW offers a +5.5 in (≈15%) longer cargo floor with the front seats upright, while the GLB has a +7.1 in (≈26%) higher trunk opening.

Additionally, the GLB has a significantly greater "depth" between the loading edge and the trunk floor — specified as +4.7 in (≈1100%).

Smaller differences include the GLB's loading edge being 2.4 in higher (+9%) and the BMW having a 0.8 in wider narrowest width (+2%); the width of the trunk opening is the same for both models.

Implications for Usability

The approximately 15% longer cargo floor of the BMW makes it more practical for very long items (e.g., slats, furniture parts, skis), especially when the rear seats remain upright. This gives the BMW an advantage for longitudinal loads and when loading or rearranging longer items in everyday use.

The GLB wins in volume and height: the significantly higher trunk opening and the greater depth between the loading edge and trunk floor create more vertical space.

This makes the GLB more practical for bulky, tall items (e.g., large boxes, cartons, tall plants) and facilitates loading voluminous cargo that cannot be laid flat.

The slightly higher loading edge of the GLB (≈2.4 in) can make lifting heavy items marginally more difficult but is a minor difference. Width differences are minimal and hardly affect usability; for long, flat loads, the BMW is clearly superior, while for tall or bulky loads, the GLB has the advantage.