All road vehicles in this country have specific limits on their weight; the details will be stamped on the VIN plate.
Exceeding any or all of these weight limits is illegal and may lead to heavy fines or even put an end to your travels until it’s corrected.
Here are some details on motorhome weights explained.
Check your motorhome VIN plate
The VIN plate is often a metal plate attached under the bonnet somewhere, but it might be a printed label attached in a cab doorway.
On it will be the VIN (Vehicle Identity Number) along with the Maximum Allowed Mass (MAM), Maximum Train Weight (MTW), and Maximums for front axle weight and rear axle weight (these will be often listed as axle 1, axle 2, axle 3 (tandem axled vehicles)).
The MAM is simply the maximum the vehicle is legally allowed to weigh; this will include everything carried in the vehicle.
MTW is the legal maximum the vehicle and any trailer it pulls may weigh, while the individual axle weights are the legal maximum weights for each axle.
It is very often the case with motorhomes that, while the MAM is not exceeded an individual axle limit can be; often the rear axle but sometimes the front.
Overloading of one axle can usually be rectified by simply moving items to a different location in the motorhome.
A few A-class vans built on lighter chassis will struggle to remain legal on the front axle due to the body adding a significant load at the front, as well as having a large drop-down bed.
Motorhome MAM weights
Often the MAM is lower than the axle totals to allow for variations of loading.
The MAM can often be uprated; first as a paper exercise to raise the MAM to the total of the axle weights, usually upgrading a 3500kg motorhome to around 3850kg MAM, but this doesn’t alter individual axle limits.
Axle limits can be uprated, but will usually involve upgrading suspension and tyres.
Air-assist rear suspension can often increase a rear-axle limit and thereby the MAM.
Front axle limits can be raised, usually by fitting stronger springs. Tyres will often need to be upgraded to allow an axle upgrade, so allow for a set of tyres in your costing.
Upgrading a motorhome’s weight
Upgrading beyond 3500kg does have other consequences besides increasing carrying capacity.
Driving licences may also require upgrading for you to legally drive a vehicle that’s more than 3500kg. If you passed your test before 1 January 1997, you will be allowed to drive up to 7500kg plus a 750kg trailer; after that date you will only be allowed to drive 3500kg plus a 750kg trailer.
Speed limits may be lower for a vehicle exceeding 3500kg MAM on the continent, while in the UK the speed limit is based on unladen mass.
On the positive side road tax is cheaper for over 3500kg (PHGV) vehicles.
Exceeding any or all of these weight limits is illegal and may lead to heavy fines or even put an end to your travels until it's corrected