Unexpected automotive benefit

[Belatucadrus]

A few months ago after a service the Honda garage told mum her cars air-conditioning needed recharging, we were in no rush so left it a bit before deciding to proceed. Not surprisingly the air con was revived, cooling was much faster and more effective but over the past few tank refills we've also noted a significant increase in range. With hindsite this shouldn't be surprising as I know the air-con unit puts a heavy load on the engine burning fuel, so if the coolant escapes or degrades the pump is going to be working that much harder burning more fuel to achieve less. It wasn't however anything I'd really thought about and I didn't expect there to be an obvious improvement in mpg. Now as I wasn't monitoring consumption before and after I have no stats to give so this is only "As it seems to me" rather than scientific fact. But if you have an old car with air conditioning it may well be worth having it checked out.