Trunk comparison: Mercedes Benz GLB vs VW ID.3

Key Differences

The Mercedes‑Benz GLB offers a cargo floor that is +9.4 in (16%) longer with the seats folded down than the VW ID.3, and with the first row of seats upright, a trunk that is +6.3 in (20%) longer.

The trunk opening of the GLB is also +5.1 in (17%) higher than that of the ID.3. In contrast, the VW ID.3 has a greater depth between the loading edge and the trunk floor: +1.6 in (33%) more than the GLB.

Smaller differences include the ID.3's loading edge being 2 in (7%) higher above the ground, as well as a slightly wider narrowest trunk width (+1.6 in / 4%) and a +3.9 in (10%) larger opening width on the GLB.

Impact on Usability

The longer loading lengths in the GLB (each +16–9.4 in) and the significantly higher trunk opening (+5.1 in) make it better suited for long or bulky items (e.g., slats, furniture parts, folded bicycles) and facilitate loading large suitcases or boxes.

The greater opening height reduces the need for edge maneuvering when loading and unloading bulky items.

The greater interior "depth" value of the ID.3 (+1.6 in / 33%) means that more vertical volume or space between the loading edge and floor can be utilized inside — practical for stacking taller items or when the floor structure is shaped differently.

However, the loading edge of the ID.3 is 2 in higher, which makes lifting heavy loads in more strenuous. In practice, this means: the ID.3 may offer more stackable height with the same footprint, while the GLB is more comfortable when loading heavy or bulky items.

Differences in width are minor (narrowest point +1.6 in / 4%, opening width +3.9 in / 10%) and only marginally affect everyday usability — wide items fit somewhat easier through the opening in the GLB, but this effect is less decisive than the length and height differences.