otherclive said:
Be aware that if you upgrade LI then the tyres will have a harder ride and need increased pressure. After contacting Firestone and GT Radial re pressures I now run at 53psi not the 42psi as specified for the Trailermaxx. So far my wardrobes are still fixed to the van!!!
Upgrading the LI means the internal tyre structure is altered, permitting higher presures and higher loads - but if the tyre limit x2 is well above the axle requirement, you don't have to and shouldn't run at maximum pressure.
Some caravan manufacturers, including Lunar, erroneously specify maximum pressure when a lower pressure is more appropriate for the axle load. My 1500kg MTPLM caravan has 185/80 R14 104/102N tyres - these permit a theoretical axle load of 1800kg (2x 900) at 65psi - so 54psi is the correct pressure, not 65psi.
The exact pressure will vary for every caravan, based on it's MTPLM, the tyre Load Index and the tyre maximum pressure.