Trunk comparison: Opel Grandland vs VW Golf Wagon (Mk5)

Key Differences
The most significant differences concern the interior length with the front seats upright as well as the vertical dimensions of the trunk in the Opel Grandland. The VW Golf 5 offers a +6.3 in (≈18%) longer cargo space with the front seats upright than the Opel Grandland.
In contrast, the Opel Grandland has a trunk depth (distance from loading edge to trunk floor) that is +4.3 in (≈220%) greater than the Golf, and the loading edge of the Grandland sits +5.5 in (≈22%) higher above the road than the Golf.
Smaller differences (under 10%) affect trunk opening height, width, and the width at the narrowest point and are not highlighted here.
Impact on Usability
The longer loading floor of the VW Golf 5 with the front seats upright makes it more practical for longer items without folding the seats (e.g., slats, skis, long boxes). When all seats are folded down, the difference is negligible (only +1%), so the usable lengths are similar once the seats are folded.
The significantly greater depth value of the Opel Grandland means a much deeper cargo area below the loading edge – this can provide more volume for tall or bulky items that fit better in a deeper recess.
At the same time, the loading edge that is about 5.5 in higher makes lifting heavy loads more difficult: the lifting happens higher above the ground and then deeper into the vehicle, which worsens ergonomics when loading.
For frequent lifting of heavy items, the Golf is therefore more convenient; for storing bulky but not too heavy goods, the Grandland can be advantageous due to its greater depth.
In short: Golf 5 = better for longer loads without folding seats and generally lower, more ergonomic loading edge. Opel Grandland = greater trunk depth and thus potentially more usable volume for certain loading types, but with worse ergonomics when lifting due to the higher loading edge.