Australian Towing Legality Check

Use when someone asks whether an Australian vehicle can legally tow a particular caravan or trailer — "can my Ranger tow a 3 tonne van", "am I over GCM", "what is the heaviest caravan I can tow", "is my towing setup legal". Given a vehicle + variant and the caravan's ATM (plus optional tow-vehicle payload), returns whether the combination is legally compliant, marginal or illegal, WHICH limit binds (braked capacity, towball download, GVM or GCM — often not the braked rating everyone quotes), the maximum ATM that is legal for that vehicle, and remaining payload. Manufacturer-spec information, not advice.

{'type': 'object', 'required': ['vehicle', 'van_atm'], 'properties': {'load': {'type': 'number', 'description': 'people + gear in the tow vehicle (kg)'}, 'van_atm': {'type': 'number', 'description': 'caravan Aggregate Trailer Mass (kg)'}, 'variant': {'type': 'string', 'description': 'trim/variant, e.g. V6 or SR5'}, 'vehicle': {'type': 'string', 'description': 'make + model, e.g. Ford Ranger'}}}