Tyre pressure in larger campers, what's you recommendation?

[julius0377]

A question for the guys with big rigs of more than 10 tonnes out there:

I see from the manual of the Atego I'm about to recieve that they recommend a tyre pressure of 2.8 bar for the 365/80 R 20 tyre dimension with singles. Thats with an axle load of 3800 kg pr. axle. It goes up to 4.0 bar for a fully loaded vehicle. (I just divided the load on the two axles equally, there might be small variations from front to back axle as I get the correct loads on a scale/weight.)

What types of pressures do you use? on what type of tyre dimension? Any recommendations for pressure in different situations like:

1. Asphalt highway (about 80 to 85 km/s top speed)
2. Dirt roads
3. "Offroad" roads. Roads with large protrusions like tree roots, stones, deep holes.
4. Mud
5. Sand

Any input much appreciated!

 

[charlieaarons]

You should fill up all fuel tanks and water tanks, and put all recovery gear, tools and spare parts in the vehicle. Then go to a weighbridge and weigh front and rear axles separately. Then add 500 or even 1000kg to the rear figure to account for all the extra stuff one carries when out travelling. Use Michelin's inflation tables for correct pressure (or whatever mfg for the tires you have). If you have XZLs I'd add 0.5-0.7 bar in front to reduce side lug wear.
On my U500 with 395/85R20 XZLs I run 6.6 bar in the rear and 4.4 bar in front. I reduce to 75% on dirt roads if bumpy or corrugated (100% if smooth) - not to exceed 65kph, 50% for very bad roads - not to exceed 35kph, 33-40% for very soft stuff like loose sand, not to exceed 20 kph. I run minimum pressure of 2.2 bar in the rear and 1.5 bar in front, I don't have bead locks.
Your tire size in Michelin XZL is rated at 7100kg/axle at 6 bar.

Charlie

 

[julius0377]

Thank you Charlie. Its going to be XZL's, so I'll source Michelins tables and use those instead of the Ategos instruction book.