Trunk comparison: BMW 3 Series Touring vs Mercedes Benz GLB

Main Differences

The Mercedes‑GLB offers significantly more space and accessibility in several areas: the height of the trunk opening is 6.3 in (22%) higher, the depth between the loading edge and trunk floor is 4.3 in (1100%) greater, the loading edge is 4.7 in (20%) higher above the ground, and the narrowest width in the trunk is 3.9 in (11%) larger than in the BMW 3 Series Touring.

Smaller differences include that the BMW has a trunk 2 in (5%) longer with the front seats upright, and the GLB is only 0.8 in (1%) longer with the seats folded down; the width of the trunk opening is 6% larger in the GLB.

Impact on Usability

The higher trunk opening (+6.3 in / 22%) and the greater narrowest width (+3.9 in / 11%) in the GLB make loading wide and tall items easier (e.g., boxes, cabinets, bicycles without disassembly).

The significantly greater depth between the loading edge and trunk floor (+4.3 in / 1100%) creates more usable storage space below the loading edge and allows bulky or tall cargo to be recessed deeper; at the same time, a much deeper load floor can make reaching or lifting heavy items more difficult.

The higher loading edge of the GLB (+4.7 in / 20%) means more lifting effort when loading—especially with heavy loads. In contrast, the 3 Series Touring has a lower loading edge, which makes lifting easier and more comfortable when frequently loading lighter items.

For long, flat items (e.g., skis, slats), the BMW has a slight everyday advantage because its trunk with the front seats upright is 2 in longer. With the seats folded down, the length differences are negligible (GLB +0.8 in).

Conclusion

Those who often transport wide, tall, or bulky items benefit from the GLB (larger opening, more depth and width). Those who value easier lifting and a somewhat longer loading area with the rear seats upright are better served by the 3 Series Touring.