Trunk comparison: Kia Sportage vs Opel Astra Wagon

Key Differences (>10%) and Their Impact on Usage
The Opel Astra Sports Tourer offers a 4.7 in (about 13%) longer cargo floor with an upright first row of seats than the Kia Sportage.
This makes the Astra more practical for longer items (skis, planks, furniture parts) that need to be transported without folding the seats; in the Sportage, such loads often require folding or angling.
The trunk opening height is 4.7 in (about 16%) higher in the Astra. This makes it easier to load tall or bulky items upright without having to tilt them significantly. For users who frequently transport large boxes, strollers, or plants, this is a clear advantage.
The measured depth from the loading edge element to the trunk floor is 5.5 in (about 1300%) greater in the Astra — meaning the Astra has a significantly deeper cargo area or a more pronounced trunk well.
Practically, this means more usable volume and space for stacking or for low-lying items. However, items also sit deeper in the Astra, so you have to reach down or bend over more often when retrieving something from the very back.
In contrast, the loading edge of the Kia Sportage sits 4.3 in (about 18%) higher above the ground.
This increases the lifting effort when loading heavy items and makes loading less convenient; however, the higher entry in the Sportage can mean higher ground clearance (e.g., on uneven terrain) and better underbody protection.
Other, Less Relevant Differences (<=10%)
The total cargo length with folded seats is only 3.5 in (about 5%) longer in the Astra — a minor advantage. The narrowest trunk width is 0.8 in (about 2%) greater in the Sportage, while the width of the trunk opening is also 0.8 in (about 2%) greater in the Astra — both differences are hardly noticeable in practice.
Conclusion — Usability
Those who regularly transport long, tall, or bulky items benefit from the Opel Astra Sports Tourer: more usable length with upright seats, a significantly higher opening, and a notably deeper cargo floor make loading easier and increase capacity.
Those who prefer higher ground clearance, a raised loading edge, or typical SUV behavior (slightly higher ground clearance, protection on uneven ground) may find advantages in the Kia Sportage — but at the cost of easier loading and an overall somewhat smaller, less deep cargo area.