If the vehicle is used mainly in any of the following particularly harsh conditions:- to tow a trailer or caravan;- on dusty roads;- for short, repeated journeys (less than 7-8 Km) and at sub-zero outdoor temperatures;- engine often idling or driving long distances at low speeds (e.g. taxi or door-to-door deliveries) or long periods of idleness.- for urban routes;the following checks must be carried out more often than indicated in the Planned Maintenance Programme:- check front disc brake pad condition and wear;- check cleanliness of bonnet and boot locks, and cleanliness and lubrication of linkages;- visually inspect condition of: engine, gearbox, transmission, rigid and flexible pipes (exhaust - fuel system - braking system) and rubber elements (gaiters - hoses - bushes - etc.);- check battery charge and battery fluid level (electrolyte);- visually inspect condition of the auxiliary drive belts;- check and, if necessary, replace pollen filter;- check and, if necessary, replace air filter.