This is true for all cars - the air condition system simply isn't designed to to be switched off for long periods. Why? The system is self-lubricating, with refrigerant oil being circulated by the compressor. If you switch the system off for 2 or 3 weeks the oil will not circulate and the joints will eventually dry out. This will result in the refrigerant gas escaping. The compressor may also seize up when you attempt to re-start the system after a long period of inactivity. A new compressor alone is £1000.

In the short term, switching off the aircon to save a few coppers on fuel may seem like wisdom. In the long run, it’ll result in a faulty air conditioning system that will cost serious money to put right.