Tyre Pressure for Corrugations and Sand: A Guide for a Loaded-Up 4WD
Running the same tyre pressure on corrugations, sand and the highway is one of the most common mistakes on a touring trip - and it matters more, not less, once you've got a loaded rooftop tent adding weight up top and shifting your centre of gravity.
Why pressure matters more with a rooftop tent fitted
A rooftop tent and its contents typically add 50-100+kg high on the vehicle (see our Weight Management guide for specifics). That extra weight, combined with a higher centre of gravity, means your tyres are working harder and your vehicle is more sensitive to being over or under-inflated for the terrain - particularly in crosswinds or on corrugated tracks where a top-heavy vehicle already handles differently.
General starting points
These are general guides, not fixed rules - always check your vehicle and tyre manufacturer's specifications, and adjust from there based on load and conditions:
- Highway/bitumen, loaded: Manufacturer's placard pressure, adjusted up slightly for a genuinely heavy load (roof-mounted tent, full fuel and water, gear in the back)
- Corrugated dirt roads: Generally lower than highway pressure to let the tyre absorb the washboard surface rather than skipping across it - a common range quoted by touring guides is around 28-32psi for a loaded 4WD, but always check what your specific tyre and vehicle combination calls for
- Sand: Lower again, often down to the high teens or low twenties psi, to increase the tyre's footprint and stop it digging in - drop pressure before you hit the sand, not after you're bogged
Reading the signs on corrugations
If the vehicle is bouncing and skipping across the top of the corrugations rather than tracking through them, pressure is usually too high for the surface. A properly aired-down tyre flexes and follows the ripples instead of hammering across them - easier on the vehicle, the tent brackets, and everyone's spine.
Don't forget to air back up
Low pressure that's fine on dirt or sand isn't safe at highway speed - it generates excess heat and increases the risk of tyre failure. Always re-inflate before getting back on sealed roads, and carry a means of doing so (12V compressor) as standard touring kit.
A loaded roof changes your margin for error
With a rooftop tent fitted, a genuinely underinflated tyre combined with a heavier, higher-riding vehicle is a worse combination than the same mistake in an unloaded car - handling in a crosswind or through a corrugated corner is noticeably more affected. It's one more reason to get pressures right before you leave sealed roads, not to guess and adjust later.
FAQ
Do I need a different tyre pressure gauge for touring?
A reliable gauge (rather than relying on a servo air hose gauge) is worth having in the vehicle, along with a compressor for airing back up before the highway.
Should I air down before or after fitting the rooftop tent for a trip?
Air down once you're actually on the corrugated or sandy section, not preemptively - you still want full highway pressure for the sealed-road drive out, especially with the extra weight and wind resistance of a loaded roof.
Does tyre pressure affect fuel use with a rooftop tent fitted?
Yes - both an overloaded roof and incorrect tyre pressure independently increase fuel consumption, so getting both right matters more on a long touring trip than a quick weekend away.
What's the risk of getting it wrong?
Overinflated tyres on corrugations reduce grip and comfort and increase wear; underinflated tyres at highway speed risk overheating and tyre failure. Match pressure to the surface and the load, and adjust as conditions change through the trip.
