Firstly, please no corsa jokes. I've got an 11 plate corsa which I have had for a year now. It has one of those things that tells you how many miles you have left before you need to fill up again. The last week or so it suddenly seems to be using A LOT more fuel than usual. For example I've done about 20 actual miles this weekend, but the number of miles it's telling me I have left has gone down by about 3 times that. I've not been sat in loads of traffic, I haven't gone o