If you want a compact, lighter solution that still offers substantial space for family trips and DIY gear, choose GiantexUK 15/21; if you need maximum volume, heavier-duty construction for hauling bulky loads like tents or large equipment, choose Asinking Car Rooftop Cargo. Both carriers solve the same problem of overflowing trunks, but they approach the challenge with different philosophies regarding size, weight, and material durability. This comparison cuts through the noise to help you decide which bag fits your specific storage needs without relying on fleeting sales figures or subjective ratings.
• Best For: Choose GiantexUK 15/21 for everyday family travel where ease of handling matters; choose Asinking for long-term camping trips or moving large DIY supplies where sheer volume and ruggedness are priorities.
The GiantexUK 15/21 Cubic Feet Car Roof Bag is designed for the driver who values efficiency and manageability. This weight advantage becomes critical if you frequently load and unload the bag yourself without a helper.
Its 15 cubic feet of storage provides ample room for the essentials of a family of five or six. The manufacturer notes that this volume can hold about three-quarters of a medium-sized suitcase, which translates to practical utility for weekend trips. You can fit several suitcases, backpacks, and perhaps some smaller boxes of tools or sports gear. The inclusion of a non-slip mat and six door hooks ensures that the contents stay put during transit, while the ten reinforced straps offer a robust method of securing the bag to various vehicle types, from sedans to SUVs.
However, this model might not be the right choice if you are planning a major relocation or a multi-week expedition requiring bulkier items. If your primary use case involves transporting oversized items like large golf bags, multiple tents, or extensive DIY repair materials, the 15 cubic foot limit could feel restrictive. The design prioritizes a streamlined profile that fits well on most cars, including those with side rails or crossbars, but it simply cannot match the internal dimensions of the larger options available. It is an ideal tool for the traveler who wants to clear out the trunk without needing a warehouse-sized container.
The Asinking Car Rooftop Cargo Carrier targets the user who demands maximum capacity and rugged reliability above all else. With a staggering 21 cubic feet of space, this bag is built to handle the heaviest loads. Its dimensions of 52 inches by 40 inches by 18 inches create a cavernous interior capable of accommodating luggage for four to six people, plus significant additional bulk. You can easily store tents, sleeping bags, foldable chairs, and golf bags that would overwhelm smaller carriers. This makes it a top contender for families embarking on extended road trips or individuals moving large quantities of goods.
We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-11-05 · 5 min read · Independent comparison
Durability is the second pillar of this product's identity. Constructed from 100% waterproof 900D PVC tarpaulin, the Asinking bag uses high-frequency welding technology on every seam. This manufacturing technique creates a triple-layer defense against water, snow, and dust, ensuring that even in severe weather conditions, your interior luggage remains dry and clean. The soft shell construction allows the bag to flex around irregular shapes, fitting various sized items that rigid boxes might reject. Furthermore, the inclusion of a combination lock on the zipper adds a layer of security that protects your belongings when parked overnight, a feature often overlooked in standard cargo bags.
The trade-off lies in the physical handling of such a substantial piece of equipment. Installing it requires more upper body strength, and you may find it necessary to have assistance when strapping it down securely. The sheer size also means it takes up more visual space on your vehicle, which might be a concern if you drive a smaller sedan or prefer a low-profile look. Additionally, while the non-slip mat and six security hooks are present, the overall footprint is larger, meaning it will not fit as snugly on smaller roof racks as a more compact unit might. It is best suited for those who prioritize volume and extreme durability over portability.
• Best for heavy DIY repairs or bulky equipment → Asinking Car Rooftop Cargo, due to its 21 cubic feet volume and 900D tarpaulin material.
• Best for harsh weather resistance → Asinking Car Rooftop Cargo, utilizing high-frequency welding and 900D PVC for superior tear-proof performance.
• Best for everyday family travel → GiantexUK 15/21, offering sufficient 15 cubic feet space without the hassle of managing excessive bulk.
• Best for flexible storage shapes → Asinking Car Rooftop Cargo, as its soft shell and larger dimensions accommodate irregular items like large tents and golf bags better.
• Best for fuel efficiency considerations → GiantexUK 15/21, since the smaller profile and lighter weight generally create less drag and require less energy to move.
• Best for vehicles with limited roof space → GiantexUK 15/21, as its 16.9 x 44.1 x 33.9 inch dimensions fit tighter roof areas more easily than the 18 x 52 x 40 inch Asinking model.
• Best for maximum security → Asinking Car Rooftop Cargo, which features a dedicated combination lock and reinforced seams for heavy-duty protection.
I would personally choose the Asinking Car Rooftop Cargo if my primary goal was carrying a heavy load of gear for a long trip or a significant DIY project. The 21 cubic feet of space and the 900D PVC construction provide a level of confidence and capacity that the smaller 15 cubic feet model simply cannot match. The extra weight is a minor inconvenience compared to the assurance that I can transport everything I need without leaving anything behind or worrying about tears in wet conditions. However, for general use cases like weekend getaways where ease of handling is paramount, the GiantexUK 15/21 remains a strong contender. Ultimately, for those tackling big jobs or long hauls, the extra volume and ruggedness of the Asinking unit make it the superior choice for serious hauling.
Yes, both models feature waterproof designs; GiantexUK uses high-quality PVC with a waterproof zipper, while Asinking utilizes 900D PVC tarpaulin with high-frequency welded seams for triple-layer protection against water and snow.
Both products are designed to be universal and work with vehicles that have or do not have roof racks, crossbars, side rails, or trays, utilizing ten reinforced straps and six door hooks for secure attachment.
Both carriers include a combination lock for the zipper to prevent unauthorized access, along with non-slip mats and security hooks to keep the bag stable and protect your vehicle's finish.
As an Amazon Associate I earn from qualifying purchases.
We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon and affiliated sites.
When you buy through links on this page, we may earn a commission from qualifying purchases at no extra cost to you.
Amazon and the Amazon logo are trademarks of Amazon or its affiliates. This site is an independent third-party review and is not affiliated with, endorsed by, or sponsored by Amazon or the product brands mentioned.