Trunk comparison: Volvo V90 vs VW Tiguan Allspace

Key Differences
With all seats upright, the Volvo V90 has a trunk that is 26.4 in (+143%) longer than the VW Tiguan Allspace. The loading edge of the Tiguan Allspace is also 6.3 in (+26%) higher above the road than that of the Volvo V90.
Smaller differences (under 10%) are: the Volvo has only about 1.6 in (2%) more loading length with folded seats and 0.8 in (2%) more length with the first row upright; the narrowest trunk width is 2 in (5%) larger in the Volvo; the trunk opening height is 0.8 in (3%) higher in the Tiguan.
Depth (loading edge → floor) and width of the trunk opening are the same in both models.
Practical Implications
Because the Volvo V90 offers significantly more cargo space with all seats upright, it is clearly more practical when several passengers need to remain seated while still transporting a lot of luggage or long items.
This advantage is especially evident in everyday scenarios with full occupancy (shopping, luggage, sports equipment), where the Tiguan Allspace has noticeably less usable space.
The higher loading edge of the Tiguan Allspace means noticeably more effort is required to lift heavy items into the trunk. For regularly heavy or bulky cargo, the lower loading height of the Volvo is more practical because lifting and sliding items around is easier.
However, when folding down the seats, the two models are largely comparable (only about 1.6 in difference), so both vehicles are similarly suitable for transport tasks with folded seats.
The slightly larger narrowest width of the Volvo (+2 in) is a small advantage when loading wider items; the minimally higher opening of the Tiguan (+0.8 in) plays hardly any role in practice.
Practical Conclusion
If you often travel fully occupied with a lot of luggage or long items or frequently load and unload heavy cargo, the Volvo V90 offers the clearer benefit. If you regularly fold down the seats and then transport large loads, the differences are minor.