Why it matters: Nose weight of the centre-axle trailer

Wrong nose weight is dangerous in two opposite directions. Too much pushes the car's nose up and the rear down — worse steering, less front grip. Too little makes the trailer unstable: on the bridge at Moerdijk, where the westerly wind pushes trucks and caravans sideways, an under-loaded centre-axle trailer becomes an unstable snaking machine at high speed. Two different kinds of limits, not one simple number that applies everywhere.