These cars are generally getting on 9years old now, very lucky if air con is still working correctly (some well informed previous owners running the system regularly). I have a mechanic mate who regasses mine when I service/mot, but must have a leak as it generally only lasts around 3-4months before pressure is too low and condensor doesn't 'click' on. Luckily we are in a country where the requirement is minimal

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I'd imagine the O-rings will have dried up and shrunk on the majority of cars over 6-7year old, resulting in ineffective systems. But the cost of fixing seems unjustifiable.
...jerry springers final word: if it aint working the extra 5bhp you get with it being off will allow you to drive that bit quicker, to allow for excellent cross-ventilation, eliminating the requirement for your aircon
