“You said my roof can hold 75 kg, but the tent specs say 300 kg — which is it?” Both. They’re measuring two different things, and confusing them is the #1 cause of overloaded roofs. This guide explains dynamic vs static load, how to read your vehicle’s ratings, and how to size an inflatable rooftop tent so you never exceed them.
Dynamic Load vs Static Load: The Core Distinction
- Dynamic load= the weight your roof can carry *while driving* (bumps, cornering, wind). This is the small number — usually 50–100 kg.
- Static load= the weight it can hold *when parked and still* (you sleeping inside). This is 4–5× higher, often 300 kg+.
Your car’s manual lists the dynamic limit. The static limit is rarely printed but is safe to estimate at ~4–5× dynamic for a well-built roof.
Where to Find Your Vehicle’s Ratings
- Open the owner’s manual → “Roof load” or “Luggage rack” section.
- Check the sticker on the driver’s door jamb — some list it there.
- Look up the crossbar maker’s dynamic rating (often lower than the car’s).
Use the lowest of these three numbers as your real limit.
Doing the Math for an Inflatable Rooftop Tent
PlayDo inflatable tents weigh 26–35 kg. Add the mattress (≈4 kg) and a little gear stored inside (≈6 kg) and you’re at ~45 kg dynamic — under almost every SUV’s 75 kg rating. That’s the big advantage of inflatable: less weight means more headroom for your gear.
What Happens If You Overload?
Sagging rails, cracked mounting points, and — worst case — a tent coming loose at speed. Overloading also voids rack warranties. When in doubt, weigh it.
Static Load and Sleepers
Two adults (≈160 kg) + tent (≈32 kg) = ~192 kg. Well under a typical 300 kg static limit. This is why rooftop tents are safe to sleep in even though the dynamic number looks small.
FAQ
Is 75 kg dynamic enough for an inflatable rooftop tent?
For almost all PlayDo models (26–35 kg) plus a thin mattress and light gear, yes. Hard shells (60–85 kg) are tighter.
How do I calculate total roof weight?
Tent + mattress + anything stored inside the closed tent + crossbar weight. Compare the sum to your dynamic rating.
Can I store gear inside the tent while driving?
A little, yes — but keep it light. Heavy items raise the center of gravity and eat into your dynamic limit.
Does an inflatable tent reduce roof load vs hard shell?
Yes, significantly. Inflatable models are roughly half the weight of aluminum hard shells, leaving more capacity for gear.
What if my car lists no roof rating?
Assume a conservative 50 kg dynamic and confirm with the dealer. Never guess on a glass-roof or unibody vehicle.
Explore the Range
- [Inflatable Rooftop Tents — lightest in the range](https://www.playdooutdoor.com/product-category/rooftop-tent/)
- [Roof Rack & Mounting Guide](https://www.playdooutdoor.com/product-category/rooftop-tent/)
- [All Rooftop Tent guides](https://www.playdooutdoor.com/)
